This section contains unified change history highlights for all
MySQL Cluster releases based on version 6.3 of the
NDB storage engine through MySQL
Cluster NDB 6.3.55. Included are all changelog
entries in the categories MySQL Cluster,
Disk Data, and Cluster
For an overview of features that were added in MySQL Cluster NDB 6.3, see What is New in MySQL Cluster NDB 6.3.
- Changes in MySQL Cluster NDB 6.3.54 (5.1.73-ndb-6.3.54)
- Changes in MySQL Cluster NDB 6.3.53 (5.1.72-ndb-6.3.53)
- Changes in MySQL Cluster NDB 6.3.52 (5.1.69-ndb-6.3.52)
- Changes in MySQL Cluster NDB 6.3.51 (5.1.67-ndb-6.3.51)
- Changes in MySQL Cluster NDB 6.3.50 (5.1.66-ndb-6.3.50)
- Changes in MySQL Cluster NDB 6.3.49 (5.1.61-ndb-6.3.49)
- Changes in MySQL Cluster NDB 6.3.47 (5.1.56-ndb-6.3.47)
- Changes in MySQL Cluster NDB 6.3.46 (5.1.56-ndb-6.3.46)
- Changes in MySQL Cluster NDB 6.3.45 (5.1.56-ndb-6.3.45)
- Changes in MySQL Cluster NDB 6.3.44 (5.1.56-ndb-6.3.44)
- Changes in MySQL Cluster NDB 6.3.43 (5.1.56-ndb-6.3.43)
- Changes in MySQL Cluster NDB 6.3.42 (5.1.51-ndb-6.3.42)
- Changes in MySQL Cluster NDB 6.3.41 (5.1.51-ndb-6.3.41)
- Changes in MySQL Cluster NDB 6.3.40 (5.1.51-ndb-6.3.40)
- Changes in MySQL Cluster NDB 6.3.39 (5.1.51-ndb-6.3.39)
- Changes in MySQL Cluster NDB 6.3.38 (5.1.47-ndb-6.3.38)
- Changes in MySQL Cluster NDB 6.3.37 (5.1.47-ndb-6.3.37)
- Changes in MySQL Cluster NDB 6.3.36 (5.1.47-ndb-6.3.36)
- Changes in MySQL Cluster NDB 6.3.35 (5.1.47-ndb-6.3.35)
- Changes in MySQL Cluster NDB 6.3.34 (5.1.44-ndb-6.3.34)
- Changes in MySQL Cluster NDB 6.3.33 (5.1.44-ndb-6.3.33)
- Changes in MySQL Cluster NDB 6.3.32 (5.1.41-ndb-6.3.32)
- Changes in MySQL Cluster NDB 6.3.31b (5.1.41-ndb-6.3.31b)
- Changes in MySQL Cluster NDB 6.3.31a (5.1.41-ndb-6.3.31a)
- Changes in MySQL Cluster NDB 6.3.31 (5.1.41-ndb-6.3.31)
- Changes in MySQL Cluster NDB 6.3.30 (5.1.39-ndb-6.3.30)
- Changes in MySQL Cluster NDB 6.3.29 (5.1.39-ndb-6.3.29)
- Changes in MySQL Cluster NDB 6.3.28b (5.1.39-ndb-6.3.28b)
- Changes in MySQL Cluster NDB 6.3.28a (5.1.39-ndb-6.3.28a)
- Changes in MySQL Cluster NDB 6.3.28 (5.1.39-ndb-6.3.28)
- Changes in MySQL Cluster NDB 6.3.27a (5.1.37-ndb-6.3.27a)
- Changes in MySQL Cluster NDB 6.3.27 (5.1.37-ndb-6.3.27)
- Changes in MySQL Cluster NDB 6.3.26 (5.1.35-ndb-6.3.26)
- Changes in MySQL Cluster NDB 6.3.25 (5.1.34-ndb-6.3.25)
- Changes in MySQL Cluster NDB 6.3.24 (5.1.32-ndb-6.3.24)
- Changes in MySQL Cluster NDB 6.3.23 (5.1.32-ndb-6.3.23)
- Changes in MySQL Cluster NDB 6.3.22 (5.1.31-ndb-6.3.22)
- Changes in MySQL Cluster NDB 6.3.21 (5.1.31-ndb-6.3.21)
- Changes in MySQL Cluster NDB 6.3.20 (5.1.30-ndb-6.3.20)
- Changes in MySQL Cluster NDB 6.3.19 (5.1.29-ndb-6.3.19)
- Changes in MySQL Cluster NDB 6.3.18 (5.1.28-ndb-6.3.18)
- Changes in MySQL Cluster NDB 6.3.17 (5.1.27-ndb-6.3.17)
- Changes in MySQL Cluster NDB 6.3.16 (5.1.24-ndb-6.3.16)
- Changes in MySQL Cluster NDB 6.3.15 (5.1.24-ndb-6.3.15)
- Changes in MySQL Cluster NDB 6.3.14 (5.1.24-ndb-6.3.14)
- Changes in MySQL Cluster NDB 6.3.13 (5.1.24-ndb-6.3.13)
- Changes in MySQL Cluster NDB 6.3.10 (5.1.23-ndb-6.3.10)
- Changes in MySQL Cluster NDB 6.3.9 (5.1.23-ndb-6.3.9)
- Changes in MySQL Cluster NDB 6.3.8 (5.1.23-ndb-6.3.8)
- Changes in MySQL Cluster NDB 6.3.7 (5.1.23-ndb-6.3.7)
- Changes in MySQL Cluster NDB 6.3.6 (5.1.22-ndb-6.3.6)
- Changes in MySQL Cluster NDB 6.3.5 (5.1.22-ndb-6.3.5)
- Changes in MySQL Cluster NDB 6.3.4 (5.1.22-ndb-6.3.4)
- Changes in MySQL Cluster NDB 6.3.3 (5.1.22-ndb-6.3.3)
- Changes in MySQL Cluster NDB 6.3.2 (5.1.22-ndb-6.3.2)
- Changes in MySQL Cluster NDB 6.3.0 (5.1.19-ndb-6.3.0)
The ndbd_redo_log_reader utility now supports a
--helpoption. Using this options causes the program to print basic usage information, and then to exit. (Bug #11749591, Bug #36805)
Cluster API: It was possible for an
Ndbobject to receive signals for handling before it was initialized, leading to thread interleaving and possible data node failure when executing a call to
Ndb::init(). To guard against this happening, a check is now made when it is starting to receive signals that the
Ndbobject is properly initialized before any signals are actually handled. (Bug #17719439)
File system errors occurring during a local checkpoint could sometimes cause an LCP to hang with no obvious cause when they were not handled correctly. Now in such cases, such errors always cause the node to fail. Note that the LQH block always shuts down the node when a local checkpoint fails; the change here is to make likely node failure occur more quickly and to make the original file system error more visible. (Bug #16961443)
CLUSTERLOGcommand (see Commands in the MySQL Cluster Management Client) caused ndb_mgm to crash on Solaris SPARC systems. (Bug #16834030)
Improved handling of lagging row change event subscribers by setting size of the GCP pool to the value of
MaxBufferedEpochs. This fix also introduces a new
MaxBufferedEpochBytesdata node configuration parameter, which makes it possible to set a total number of bytes per node to be reserved for buffering epochs. In addition, a new
DUMPcode (8013) has been added which causes a list a lagging subscribers for each node to be printed to the cluster log (see DUMP 8013). (Bug #16203623)
When a node fails, the Distribution Handler (
DBDIHkernel block) takes steps together with the Transaction Coordinator (
DBTC) to make sure that all ongoing transactions involving the failed node are taken over by a surviving node and either committed or aborted. Transactions taken over which are then committed belong in the epoch that is current at the time the node failure occurs, so the surviving nodes must keep this epoch available until the transaction takeover is complete. This is needed to maintain ordering between epochs.
A problem was encountered in the mechanism intended to keep the current epoch open which led to a race condition between this mechanism and that normally used to declare the end of an epoch. This could cause the current epoch to be closed prematurely, leading to failure of one or more surviving data nodes. (Bug #14623333, Bug #16990394)
When performing an
INSERT ... ON DUPLICATE KEY UPDATEon an
NDBtable where the row to be inserted already existed and was locked by another transaction, the error message returned from the
INSERTfollowing the timeout was Transaction already aborted instead of the expected Lock wait timeout exceeded. (Bug #14065831, Bug #65130)
Cluster API: For each log event retrieved using the MGM API, the log event category (
ndb_mgm_event_category) was simply cast to an
enumtype, which resulted in invalid category values. Now an offset is added to the category following the cast to ensure that the value does not fall out of the allowed range.Note
This change was reverted by the fix for Bug #18354165. See the MySQL Cluster API Developer documentation for
ndb_logevent_get_next(), for more information.
References: See also: Bug #18354165.
Functionality Added or Changed
Cluster API: Added
DUMPcode 2514, which provides information about counts of transaction objects per API node. For more information, see DUMP 2514. See also Commands in the MySQL Cluster Management Client. (Bug #15878085)
When ndb_restore fails to find a table, it now includes in the error output an NDB API error code giving the reason for the failure. (Bug #16329067)
The NDB Error-Reporting Utility (ndb_error_reporter) failed to include the cluster nodes' log files in the archive it produced when the
FILEoption was set for the parameter
LogDestination. (Bug #16765651)
References: See also: Bug #11752792, Bug #44082.
Added the ndb_error_reporter options
--connection-timeout, which makes it possible to set a timeout for connecting to nodes,
--dry-scp, which disables scp connections to remote hosts, and
--skip-nodegroup, which skips all nodes in a given node group. (Bug #16602002)
References: See also: Bug #11752792, Bug #44082.
Attempting to perform additional operations such as
ADD COLUMNas part of an
ALTER [ONLINE | OFFLINE] TABLE ... RENAME ...statement is not supported, and now fails with an ER_NOT_SUPPORTED_YET error. (Bug #16021021)
Purging the binary logs could sometimes cause mysqld to crash. (Bug #15854719)
Due to a known issue in the MySQL Server, it is possible to drop the
PERFORMANCE_SCHEMAdatabase. (Bug #15831748) In addition, when executed on a MySQL Server acting as a MySQL Cluster SQL node,
DROP DATABASEcaused this database to be dropped on all SQL nodes in the cluster. Now, when executing a distributed drop of a database,
NDBdoes not delete tables that are local only. This prevents MySQL system databases from being dropped in such cases. (Bug #14798043)
References: See also: Bug #15831748.
ndb_error-reporter did not support the
--helpoption. (Bug #11756666, Bug #48606)
References: See also: Bug #11752792, Bug #44082.
A number of fixes for ndb_error_reporter have been backported from MySQL Cluster NDB 7.0 and later to this NDB 6.3 release, and are listed here:
Bug #11764570, Bug #57417: If
LogDestination=FILEis included without a file name, use
ndb_as the default.
Bug #16765651: Add
*to scp command, to include all log files
Since NDB 6.3 does not support the
NodeGroupconfiguration parameter, node groups cannot be queried using ndb_config; use ndb_mgm -e show to get the node groups for the
Bug #11756666, Bug #48606: Add missing
(Bug #11752792, Bug #44082)
Node failure during the dropping of a table could lead to the node hanging when attempting to restart.
When this happened, the
NDBinternal dictionary (
DBDICT) lock taken by the drop table operation was held indefinitely, and the logical global schema lock taken by the SQL the drop table operation from which the drop operation originated was held until the
NDBinternal operation timed out. To aid in debugging such occurrences, a new dump code,
DUMP DictDumpLockQueue), which dumps the contents of the
DICTlock queue, has been added in the ndb_mgm client. (Bug #14787522)
A slow filesystem during local checkpointing could exert undue pressure on
DBDIHkernel block file page buffers, which in turn could lead to a data node crash when these were exhausted. This fix limits the number of table definition updates that
DBDIHcan issue concurrently. (Bug #14828998)
Cluster API: When the buffer pool used for
KeyInfofrom NDB API requests for primary key and scans was exhausted while receiving the
KeyInfo, the error handling path did not correctly abort the scan request. Symptoms of this incorrect error handling included the NDB API client that requested the scan experiencing a long timeout, as well as permanent leakage of the scan record, scan fragment records, and linked operation record associated with the scan.
This issue is not present in MySQL Cluster NDB 7.0 and later, due to the replacement of the fixed-size single-purpose buffers for
LongMessageBuffer, as well as improvements in error handling. (Bug #14386849)
When reloading the redo log during a node or system restart, and with
NoOfFragmentLogFilesgreater than or equal to 42, it was possible for metadata to be read for the wrong file (or files). Thus, the node or nodes involved could try to reload the wrong set of data. (Bug #14389746)
If the Transaction Coordinator aborted a transaction in the “prepared” state, this could cause a resource leak. (Bug #14208924)
DUMP 2303in the ndb_mgm client now includes the status of the single fragment scan record reserved for a local checkpoint. (Bug #13986128)
A shortage of scan fragment records in
DBTCresulted in a leak of concurrent scan table records and key operation records. (Bug #13966723)
In some circumstances, transactions could be lost during an online upgrade. (Bug #13834481)
When trying to use ndb_size.pl
portto connect to a MySQL server running on a nonstandard port, the
portargument was ignored. (Bug #13364905, Bug #62635)
Attempting to add both a column and an index on that column in the same online
ALTER TABLEstatement caused mysqld to fail. Although this issue affected only the mysqld shipped with MySQL Cluster, the table named in the
ALTER TABLEcould use any storage engine for which online operations are supported. (Bug #12755722)
Cluster API: When an NDB API application called
NdbScanOperation::nextResult()again after the previous call had returned end-of-file (return code 1), a transaction object was leaked. Now when this happens, NDB returns error code 4210 (Ndb sent more info than length specified); previouslyu in such cases, -1 was returned. In addition, the extra transaction object associated with the scan is freed, by returning it to the transaction coordinator's idle list. (Bug #11748194)
When a failure of multiple data nodes during a local checkpoint (LCP) that took a long time to complete included the node designated as master, any new data nodes attempting to start before all ongoing LCPs were completed later crashed. This was due to the fact that node takeover by the new master cannot be completed until there are no pending local checkpoints. Long-running LCPs such as those which triggered this issue can occur when fragment sizes are sufficiently large (see MySQL Cluster Nodes, Node Groups, Replicas, and Partitions, for more information). Now in such cases, data nodes (other than the new master) are kept from restarting until the takeover is complete. (Bug #13323589)
When deleting from multiple tables using a unique key in the
WHEREcondition, the wrong rows were deleted. In addition,
UPDATEtriggers failed when rows were changed by deleting from or updating multiple tables. (Bug #12718336, Bug #61705, Bug #12728221)
When replicating DML statements with
IGNOREbetween clusters, the number of operations that failed due to nonexistent keys was expected to be no greater than the number of defined operations of any single type. Because the slave SQL thread defines operations of multiple types in batches together, code which relied on this assumption could cause mysqld to fail. (Bug #12859831)
When failure handling of an API node takes longer than 300 seconds, extra debug information is included in the resulting output. In cases where the API node's node ID was greater than 48, these extra debug messages could lead to a crash, and confuing output otherwise. This was due to an attempt to provide information specific to data nodes for API nodes as well. (Bug #62208)
In rare cases, a series of node restarts and crashes during restarts could lead to errors while reading the redo log. (Bug #62206)
When global checkpoint indexes were written with no intervening end-of-file or megabyte border markers, this could sometimes lead to a situation in which the end of the redo log was mistakenly regarded as being between these GCIs, so that if the restart of a data node took place before the start of the next redo log was overwritten, the node encountered an Error while reading the REDO log. (Bug #12653993, Bug #61500)
References: See also: Bug #56961.
Error reporting has been improved for cases in which API nodes are unable to connect due to apparent unavailability of node IDs. (Bug #12598398)
Error messages for Failed to convert connection transporter registration problems were inspecific. (Bug #12589691)
Under certain rare circumstances, a data node process could fail with Signal 11 during a restart. This was due to uninitialized variables in the
QMGRkernel block. (Bug #12586190)
Handling of the
MaxNoOfAttributesconfiguration parameters was not consistent in all parts of the
NDBkernel, and were only strictly enforced by the
SUMAkernel blocks. This could lead to problems when tables could be created but not replicated. Now these parameters are treated by
DBDICTas suggested maximums rather than hard limits, as they are elsewhere in the
NDBkernel. (Bug #61684)
Cluster API: Within a transaction, after creating, executing, and closing a scan, calling
NdbTransaction::refresh()after creating and executing but not closing a second scan caused the application to crash. (Bug #12646659)
Two unused test files in
storage/ndb/test/sqlcontained incorrect versions of the GNU Lesser General Public License. The files and the directory containing them have been removed. (Bug #11810156)
References: See also: Bug #11810224.
Cluster API: Performing interpreted operations using a unique index did not work correctly, because the interpret bit was kept when sending the lookup to the index table.
A scan with a pushed condition (filter) using the
CommittedReadlock mode could hang for a short interval when it was aborted when just as it had decided to send a batch. (Bug #11932525)
When aborting a multi-read range scan exactly as it was changing ranges in the local query handler, LQH could fail to detect it, leaving the scan hanging. (Bug #11929643)
Disk Data: Limits imposed by the size of
SharedGlobalMemorywere not always enforced consistently with regard to Disk Data undo buffers and log files. This could sometimes cause a
CREATE LOGFILE GROUPor
ALTER LOGFILE GROUPstatement to fail for no apparent reason, or cause the log file group specified by
InitialLogFileGroupnot to be created when starting the cluster. (Bug #57317)
Functionality Added or Changed
Functionality Added or Changed
--skip-broken-objectsoption for ndb_restore. This option causes ndb_restore to ignore tables corrupted due to missing blob parts tables, and to continue reading from the backup file and restoring the remaining tables. (Bug #54613)
References: See also: Bug #51652.
Two related problems could occur with read-committed scans made in parallel with transactions combining multiple (concurrent) operations:
When committing a multiple-operation transaction that contained concurrent insert and update operations on the same record, the commit arrived first for the insert and then for the update. If a read-committed scan arrived between these operations, it could thus read incorrect data; in addition, if the scan read variable-size data, it could cause the data node to fail.
When rolling back a multiple-operation transaction having concurrent delete and insert operations on the same record, the abort arrived first for the delete operation, and then for the insert. If a read-committed scan arrived between the delete and the insert, it could incorrectly assume that the record should not be returned (in other words, the scan treated the insert as though it had not yet been committed).
A row insert or update followed by a delete operation on the same row within the same transaction could in some cases lead to a buffer overflow. (Bug #59242)
References: See also: Bug #56524. This issue is a regression of: Bug #35208.
FAIL_REPsignal, used inside the NDB kernel to declare that a node has failed, now includes the node ID of the node that detected the failure. This information can be useful in debugging. (Bug #58904)
In some circumstances, an SQL trigger on an
NDBtable could read stale data. (Bug #58538)
During a node takeover, it was possible in some circumstances for one of the remaining nodes to send an extra transaction confirmation (
LQH_TRANSCONF) signal to the
DBTCkernel block, conceivably leading to a crash of the data node trying to take over as the new transaction coordinator. (Bug #58453)
A query having multiple predicates joined by
WHEREclause and which used the
sort_unionaccess method (as shown using
EXPLAIN) could return duplicate rows. (Bug #58280)
Trying to drop an index while it was being used to perform scan updates caused data nodes to crash. (Bug #58277, Bug #57057)
When handling failures of multiple data nodes, an error in the construction of internal signals could cause the cluster's remaining nodes to crash. This issue was most likely to affect clusters with large numbers of data nodes. (Bug #58240)
The number of rows affected by a statement that used a
WHEREclause having an
INcondition with a value list containing a great many elements, and that deleted or updated enough rows such that
NDBprocessed them in batches, was not computed or reported correctly. (Bug #58040)
A query using
BETWEENas part of a pushed-down
WHEREcondition could cause mysqld to hang or crash. (Bug #57735)
In some circumstances, it was possible for mysqld to begin a new multi-range read scan without having closed a previous one. This could lead to exhaustion of all scan operation objects, transaction objects, or lock objects (or some combination of these) in
NDB, causing queries to fail with such errors as Lock wait timeout exceeded or Connect failure - out of connection objects. (Bug #57481)
References: See also: Bug #58750.
NULLon a table with a unique index created with
columnalways returned an empty result. (Bug #57032)
engine_condition_pushdownenabled, a query using
ENUMcolumn of an
NDBtable failed to return any results. This issue is resolved by disabling
engine_condition_pushdownwhen performing such queries. (Bug #53360)
When a slash character (
/) was used as part of the name of an index on an
NDBtable, attempting to execute a
TRUNCATE TABLEstatement on the table failed with the error Index not found, and the table was rendered unusable. (Bug #38914)
Disk Data: In certain cases, a race condition could occur when
DROP LOGFILE GROUPremoved the logfile group while a read or write of one of the effected files was in progress, which in turn could lead to a crash of the data node. (Bug #59502)
Disk Data: A race condition could sometimes be created when
DROP TABLESPACEwas run concurrently with a local checkpoint; this could in turn lead to a crash of the data node. (Bug #59501)
Disk Data: Performing what should have been an online drop of a multi-column index was actually performed offline. (Bug #55618)
Disk Data: When at least one data node was not running, queries against the
INFORMATION_SCHEMA.FILEStable took an excessive length of time to complete because the MySQL server waited for responses from any stopped nodes to time out. Now, in such cases, MySQL does not attempt to contact nodes which are not known to be running. (Bug #54199)
Cluster API: Attempting to read the same value (using
getValue()) more than 9000 times within the same transaction caused the transaction to hang when executed. Now when more reads are performed in this way than can be accommodated in a single transaction, the call to
execute()fails with a suitable error. (Bug #58110)
Functionality Added or Changed
Important Change: The
Idconfiguration parameter used with MySQL Cluster management, data, and API nodes (including SQL nodes) is now deprecated, and the
NodeIdparameter (long available as a synonym for
Idwhen configuring these types of nodes) should be used instead.
Idcontinues to be supported for reasons of backward compatibility, but now generates a warning when used with these types of nodes, and is subject to removal in a future release of MySQL Cluster.
This change affects the name of the configuration parameter only, establishing a clear preference for
[api]sections of the MySQL Cluster global configuration (
config.ini) file. The behavior of unique identifiers for management, data, and SQL and API nodes in MySQL Cluster has not otherwise been altered.
Idparameter as used in the
[computer]section of the MySQL Cluster global configuration file is not affected by this change.
Packaging: MySQL Cluster RPM distributions did not include a
shared-compatRPM for the MySQL Server, which meant that MySQL applications depending on
libmysqlclient.so.15(MySQL 5.0 and earlier) no longer worked. (Bug #38596)
LQHKEYREQrequest message used by the local query handler when checking the major schema version of a table, being only 16 bits wide, could cause this check to fail with an Invalid schema version error (
NDBerror code 1227). This issue occurred after creating and dropping (and re-creating) the same table 65537 times, then trying to insert rows into the table. (Bug #57896)
References: See also: Bug #57897.
An internal buffer overrun could cause a data node to fail. (Bug #57767)
Data nodes compiled with gcc 4.5 or higher crashed during startup. (Bug #57761)
ndb_restore now retries failed transactions when replaying log entries, just as it does when restoring data. (Bug #57618)
During a GCP takeover, it was possible for one of the data nodes not to receive a
SUB_GCP_COMPLETE_REPsignal, with the result that it would report itself as
GCP_COMMITTINGwhile the other data nodes reported
GCP_PREPARING. (Bug #57522)
WHEREclause of the form
when selecting from an
NDBtable having a primary key on multiple columns could result in Error 4259 Invalid set of range scan bounds if
range2started exactly where
range1ended and the primary key definition declared the columns in a different order relative to the order in the table's column list. (Such a query should simply return all rows in the table, since any expression
is always true.)
CREATE TABLE t (a, b, PRIMARY KEY (b, a)) ENGINE NDB;
This issue could then be triggered by a query such as this one:
SELECT * FROM t WHERE b < 8 OR b >= 8;
In addition, the order of the ranges in the
WHEREclause was significant; the issue was not triggered, for example, by the query
SELECT * FROM t WHERE b <= 8 OR b > 8. (Bug #57396)
A GCP stop is detected using 2 parameters which determine the maximum time that a global checkpoint or epoch can go unchanged; one of these controls this timeout for GCPs and one controls the timeout for epochs. Suppose the cluster is configured such that
TimeBetweenEpochsTimeoutis 100 ms but
HeartbeatIntervalDbDbis 1500 ms. A node failure can be signalled after 4 missed heartbeats—in this case, 6000 ms. However, this would exceed
TimeBetweenEpochsTimeout, causing false detection of a GCP. To prevent this from happening, the configured value for
TimeBetweenEpochsTimeoutis automatically adjusted, based on the values of
The current issue arose when the automatic adjustment routine did not correctly take into consideration the fact that, during cascading node-failures, several intervals of length
4 * (HeartbeatIntervalDBDB + ArbitrationTimeout)may elapse before all node failures have internally been resolved. This could cause false GCP detection in the event of a cascading node failure. (Bug #57322)
NDBtable having a
VARCHARcolumn as its primary key failed to return all matching rows. (Bug #56853)
When a data node angel process failed to fork off a new worker process (to replace one that had failed), the failure was not handled. This meant that the angel process either transformed itself into a worker process, or itself failed. In the first case, the data node continued to run, but there was no longer any angel to restart it in the event of failure, even with
StopOnErrorset to 0. (Bug #53456)
Cluster API: An application dropping a table at the same time that another application tried to set up a replication event on the same table could lead to a crash of the data node. The same issue could sometimes cause
NdbEventOperation::execute()to hang. (Bug #57886)
Cluster API: An NDB API client program under load could abort with an assertion error in
TransporterFacade::remove_from_cond_wait_queue. (Bug #51775)
References: See also: Bug #32708.
Functionality Added or Changed
References: See also: Bug #34325, Bug #11747863.
Cluster API: The MGM API function
ndb_mgm_get_version(), which was previously internal, has now been moved to the public API. This function can be used to get
NDBstorage engine and other version information from the management server. (Bug #51310)
References: See also: Bug #51273.
A data node can be shut down having completed and synchronized a given GCI
x, while having written a great many log records belonging to the next GCI
x+ 1, as part of normal operations. However, when starting, completing, and synchronizing GCI
x+ 1, then the log records from original start must not be read. To make sure that this does not happen, the REDO log reader finds the last GCI to restore, scans forward from that point, and erases any log records that were not (and should never be) used.
The current issue occurred because this scan stopped immediately as soon as it encountered an empty page. This was problematic because the REDO log is divided into several files; thus, it could be that there were log records in the beginning of the next file, even if the end of the previous file was empty. These log records were never invalidated; following a start or restart, they could be reused, leading to a corrupt REDO log. (Bug #56961)
An error in program flow in
ndbd.cppcould result in data node shutdown routines being called multiple times. (Bug #56890)
DROP TABLEoperations among several SQL nodes attached to a MySQL Cluster. the
LOCK_OPENlock normally protecting mysqld's internal table list is released so that other queries or DML statements are not blocked. However, to make sure that other DDL is not executed simultaneously, a global schema lock (implemented as a row-level lock by
NDB) is used, such that all operations that can modify the state of the mysqld internal table list also need to acquire this global schema lock. The
SHOW TABLE STATUSstatement did not acquire this lock. (Bug #56841)
In certain cases,
DROP DATABASEcould sometimes leave behind a cached table object, which caused problems with subsequent DDL operations. (Bug #56840)
Memory pages used for
DataMemory, once assigned to ordered indexes, were not ever freed, even after any rows that belonged to the corresponding indexes had been deleted. (Bug #56829)
MySQL Cluster stores, for each row in each
NDBtable, a Global Checkpoint Index (GCI) which identifies the last committed transaction that modified the row. As such, a GCI can be thought of as a coarse-grained row version.
Due to changes in the format used by
NDBto store local checkpoints (LCPs) in MySQL Cluster NDB 6.3.11, it could happen that, following cluster shutdown and subsequent recovery, the GCI values for some rows could be changed unnecessarily; this could possibly, over the course of many node or system restarts (or both), lead to an inconsistent database. (Bug #56770)
When multiple SQL nodes were connected to the cluster and one of them stopped in the middle of a DDL operation, the mysqld process issuing the DDL timed out with the error distributing
tbl_nametimed out. Ignoring. (Bug #56763)
ALTER TABLE ... ADD COLUMNoperation that changed the table schema such that the number of 32-bit words used for the bitmask allocated to each DML operation increased during a transaction in DML which was performed prior to DDL which was followed by either another DML operation or—if using replication—a commit, led to data node failure.
This was because the data node did not take into account that the bitmask for the before-image was smaller than the current bitmask, which caused the node to crash. (Bug #56524)
References: This issue is a regression of: Bug #35208.
The text file
cluster_change_hist.txtcontaining old MySQL Cluster changelog information was no longer being maintained, and so has been removed from the tree. (Bug #56116)
The failure of a data node during some scans could cause other data nodes to fail. (Bug #54945)
Exhausting the number of available commit-ack markers (controlled by the
MaxNoOfConcurrentTransactionsparameter) led to a data node crash. (Bug #54944)
When running a
TEXTcolumns, memory was allocated for the columns but was not freed until the end of the
SELECT. This could cause problems with excessive memory usage when dumping (using for example mysqldump) tables with such columns and having many rows, large column values, or both. (Bug #52313)
References: See also: Bug #56488, Bug #50310.
Functionality Added or Changed
Important Change: More finely grained control over restart-on-failure behavior is provided with two new data node configuration parameters
MaxStartFailRetrieslimits the total number of retries made before giving up on starting the data node;
StartFailRetryDelaysets the number of seconds between retry attempts.
These parameters are used only if
StopOnErroris set to 0.
For more information, see Defining MySQL Cluster Data Nodes. (Bug #54341)
Following a failure of the master data node, the new master sometimes experienced a race condition which caused the node to terminate with a GcpStop error. (Bug #56044)
The warning MaxNoOfExecutionThreads (
#) > LockExecuteThreadToCPU count (
#), this could cause contention could be logged when running ndbd, even though the condition described can occur only when using ndbmtd. (Bug #54342)
The graceful shutdown of a data node could sometimes cause transactions to be aborted unnecessarily. (Bug #18538)
References: See also: Bug #55641.
Functionality Added or Changed
Important Change; Cluster API: The poll and select calls made by the MGM API were not interrupt-safe; that is, a signal caught by the process while waiting for an event on one or more sockets returned error -1 with
errnoset to EINTR. This caused problems with MGM API functions such as
To fix this problem, the internal
ndb_socket_poller::poll()function has been made EINTR-safe.
The old version of this function has been retained as
poll_unsafe(), for use by those parts of NDB that do not need the EINTR-safe version of the function. (Bug #55906)
When another data node failed, a given data node
DBTCkernel block could time out while waiting for
DBDIHto signal commits of pending transactions, leading to a crash. Now in such cases the timeout generates a prinout, and the data node continues to operate. (Bug #55715)
The configure.js option
WITHOUT_DYNAMIC_PLUGINS=TRUEwas ignored when building MySQL Cluster for Windows using CMake. Among the effects of this issue was that CMake attempted to build the
InnoDBstorage engine as a plugin (
.DLLfile) even though the
InnoDB Pluginis not currently supported by MySQL Cluster. (Bug #54913)
It was possible for a
DROP DATABASEstatement to remove
NDBhidden blob tables without removing the parent tables, with the result that the tables, although hidden to MySQL clients, were still visible in the output of ndb_show_tables but could not be dropped using ndb_drop_table. (Bug #54788)
An excessive number of timeout warnings (normally used only for debugging) were written to the data node logs. (Bug #53987)
Disk Data: As an optimization when inserting a row to an empty page, the page is not read, but rather simply initialized. However, this optimzation was performed in all cases when an empty row was inserted, even though it should have been done only if it was the first time that the page had been used by a table or fragment. This is because, if the page had been in use, and then all records had been released from it, the page still needed to be read to learn its log sequence number (LSN).
This caused problems only if the page had been flushed using an incorrect LSN and the data node failed before any local checkpoint was completed—which would remove any need to apply the undo log, hence the incorrect LSN was ignored.
The user-visible result of the incorrect LSN was that it caused the data node to fail during a restart. It was perhaps also possible (although not conclusively proven) that this issue could lead to incorrect data. (Bug #54986)
Functionality Added or Changed
Restrictions on some types of mismatches in column definitions when restoring data using ndb_restore have been relaxed. These include the following types of mismatches:
Different default values
Different distribution key settings
Now, when one of these types of mismatches in column definitions is encountered, ndb_restore no longer stops with an error; instead, it accepts the data and inserts it into the target table, while issuing a warning to the user.
For more information, see ndb_restore — Restore a MySQL Cluster Backup. (Bug #54423)
References: See also: Bug #53810, Bug #54178, Bug #54242, Bug #54279.
HeartbeatOrderdata node configuration parameter, which can be used to set the order in which heartbeats are transmitted between data nodes. This parameter can be useful in situations where multiple data nodes are running on the same host and a temporary disruption in connectivity between hosts would otherwise cause the loss of a node group, leading to failure of the cluster. (Bug #52182)
The disconnection of all API nodes (including SQL nodes) during an
ALTER TABLEcaused a memory leak. (Bug #54685)
If a node shutdown (either in isolation or as part of a system shutdown) occurred directly following a local checkpoint, it was possible that this local checkpoint would not be used when restoring the cluster. (Bug #54611)
When performing an online alter table where 2 or more SQL nodes connected to the cluster were generating binary logs, an incorrect message could be sent from the data nodes, causing mysqld processes to crash. This problem was often difficult to detect, because restarting SQL node or data node processes could clear the error, and because the crash in mysqld did not occur until several minutes after the erroneous message was sent and received. (Bug #54168)
A table having the maximum number of attributes permitted could not be backed up using the ndb_mgm client.Note
The maximum number of attributes supported per table is not the same for all MySQL Cluster releases. See Limits Associated with Database Objects in MySQL Cluster, to determine the maximum that applies in the release which you are using.
During initial node restarts, initialization of the REDO log was always performed 1 node at a time, during start phase 4. Now this is done during start phase 2, so that the initialization can be performed in parallel, thus decreasing the time required for initial restarts involving multiple nodes. (Bug #50062)
Cluster API: When using the NDB API, it was possible to rename a table with the same name as that of an existing table.Note
This issue did not affect table renames executed using SQL on MySQL servers acting as MySQL Cluster API nodes.
Cluster API: An excessive number of client connections, such that more than 1024 file descriptors, sockets, or both were open, caused NDB API applications to crash. (Bug #34303)
Functionality Added or Changed
--wait-nodesoption has been added for ndb_waiter. When this option is used, the program waits only for the nodes having the listed IDs to reach the desired state. For more information, see ndb_waiter — Wait for MySQL Cluster to Reach a Given Status. (Bug #52323)
--skip-unknown-objectsoption for ndb_restore. This option causes ndb_restore to ignore any schema objects which it does not recognize. Currently, this is useful chiefly for restoring native backups made from a cluster running MySQL Cluster NDB 7.0 to a cluster running MySQL Cluster NDB 6.3.
Incompatible Change; Cluster API: The default behavior of the NDB API Event API has changed as follows:
Previously, when creating an
Event, DDL operations (alter and drop operations on tables) were automatically reported on any event operation that used this event, but as a result of this change, this is no longer the case. Instead, you must now invoke the event's
setReport()method, with the new
ER_DDL, to get this behavior.
For existing NDB API applications where you wish to retain the old behavior, you must update the code as indicated previously, then recompile, following an upgrade. Otherwise, DDL operations are no longer reported after upgrading
When attempting to create an
NDBtable on an SQL node that had not yet connected to a MySQL Cluster management server since the SQL node's last restart, the
CREATE TABLEstatement failed as expected, but with the unexpected Error 1495 For the partitioned engine it is necessary to define all partitions. (Bug #11747335, Bug #31853)
Creating a Disk Data table, dropping it, then creating an in-memory table and performing a restart, could cause data node processes to fail with errors in the
DBTUPkernel block if the new table's internal ID was the same as that of the old Disk Data table. This could occur because undo log handling during the restart did not check that the table having this ID was now in-memory only. (Bug #53935)
A table created while
ndb_table_no_loggingwas enabled was not always stored to disk, which could lead to a data node crash with Error opening DIH schema files for table. (Bug #53934)
An internal buffer allocator used by
NDBhas the form
alloc(and attempts to allocate
wantedpages, but is permitted to allocate a smaller number of pages, between
minimum. However, this allocator could sometimes allocate fewer than
minimumpages, causing problems with multi-threaded building of ordered indexes. (Bug #53580)
When compiled with support for
epollbut this functionality is not available at runtime, MySQL Cluster tries to fall back to use the
select()function in its place. However, an extra
ndbout_c()call in the transporter registry code caused ndbd to fail instead. (Bug #53482)
NDBtruncated a column declared as
DECIMAL(65,0)to a length of 64. Now such a column is accepted and handled correctly. In cases where the maximum length (65) is exceeded,
NDBnow raises an error instead of truncating. (Bug #53352)
When a watchdog shutdown occurred due to an error, the process was not terminated quickly enough, sometimes resulting in a hang. (To correct this, the internal
_exit()function is now called in such situations, rather than
exit().) (Bug #53246)
DataMemoryhigher than 4G on 32-bit platforms caused ndbd to crash, instead of failing gracefully with an error. (Bug #52536, Bug #50928)
NDB did not distinguish correctly between table names differing only by lettercase when
lower_case_table_nameswas set to 0. (Bug #33158)
ndb_mgm -e "ALL STATUS"erroneously reported that data nodes remained in start phase 0 until they had actually started.
Functionality Added or Changed
Cluster API: It is now possible to determine, using the ndb_desc utility or the NDB API, which data nodes contain replicas of which partitions. For ndb_desc, a new
--extra-node-infooption is added to cause this information to be included in its output. A new method
Table::getFragmentNodes()is added to the NDB API for obtaining this information programmatically. (Bug #51184)
DUMPcommands returned output to all ndb_mgm clients connected to the same MySQL Cluster. Now, these commands return their output only to the ndb_mgm client that actually issued the command. (Bug #40865)
If a node or cluster failure occurred while mysqld was scanning the
ndb.ndb_schematable (which it does when attempting to connect to the cluster), insufficient error handling could lead to a crash by mysqld in certain cases. This could happen in a MySQL Cluster with a great many tables, when trying to restart data nodes while one or more mysqld processes were restarting. (Bug #52325)
After running a mixed series of node and system restarts, a system restart could hang or fail altogether. This was caused by setting the value of the newest completed global checkpoint too low for a data node performing a node restart, which led to the node reporting incorrect GCI intervals for its first local checkpoint. (Bug #52217)
When performing a complex mix of node restarts and system restarts, the node that was elected as master sometimes required optimized node recovery due to missing
REDOinformation. When this happened, the node crashed with Failure to recreate object ... during restart, error 721 (because the
DBDICTrestart code was run twice). Now when this occurs, node takeover is executed immediately, rather than being made to wait until the remaining data nodes have started. (Bug #52135)
References: See also: Bug #48436.
The redo log protects itself from being filled up by periodically checking how much space remains free. If insufficient redo log space is available, it sets the state
TAIL_PROBLEMwhich results in transactions being aborted with error code 410 (out of redo log). However, this state was not set following a node restart, which meant that if a data node had insufficient redo log space following a node restart, it could crash a short time later with Fatal error due to end of REDO log. Now, this space is checked during node restarts. (Bug #51723)
The output of the ndb_mgm client
REPORT BACKUPSTATUScommand could sometimes contain errors due to uninitialized data. (Bug #51316)
GROUP BYquery against
NDBtables sometimes did not use any indexes unless the query included a
FORCE INDEXoption. With this fix, indexes are used by such queries (where otherwise possible) even when
FORCE INDEXis not specified. (Bug #50736)
The ndb_mgm client sometimes inserted extra prompts within the output of the
REPORT MEMORYUSAGEcommand. (Bug #50196)
Issuing a command in the ndb_mgm client after it had lost its connection to the management server could cause the client to crash. (Bug #49219)
The ndb_print_backup_file utility failed to function, due to a previous internal change in the NDB code. (Bug #41512, Bug #48673)
MemReportFrequencyconfiguration parameter was set in
config.ini, the ndb_mgm client
REPORT MEMORYUSAGEcommand printed its output multiple times. (Bug #37632)
ndb_mgm -e "... REPORT ..." did not write any output to
The fix for this issue also prevents the cluster log from being flooded with
DataMemoryusage reaches 100%, and insures that when the usage is decreased, an appropriate message is written to the cluster log. (Bug #31542, Bug #44183, Bug #49782)
Disk Data: Inserts of blob column values into a MySQL Cluster Disk Data table that exhausted the tablespace resulted in misleading no such tuple error messages rather than the expected error tablespace full.
This issue appeared similar to Bug #48113, but had a different underlying cause. (Bug #52201)
References: See also: Bug #48113.
Disk Data: The error message returned after atttempting to execute
ALTER LOGFILE GROUPon an nonexistent logfile group did not indicate the reason for the failure. (Bug #51111)
Cluster API: When reading blob data with lock mode
LM_SimpleRead, the lock was not upgraded as expected. (Bug #51034)
Cluster API: A number of issues were corrected in the NDB API coding examples found in the
storage/ndb/ndbapi-examplesdirectory in the MySQL Cluster source tree. These included possible endless recursion in
ndbapi_scan.cppas well as problems running some of the examples on systems using Windows or Mac OS X due to the lettercase used for some table names. (Bug #30552, Bug #30737)
Functionality Added or Changed
A new configuration parameter
HeartbeatThreadPrioritymakes it possible to select between a first-in, first-out or round-round scheduling policy for management node and API node heartbeat threads, as well as to set the priority of these threads. See Defining a MySQL Cluster Management Server, or Defining SQL and Other API Nodes in a MySQL Cluster, for more information. (Bug #49617)
Disk Data: The ndb_desc utility can now show the extent space and free extent space for subordinate
TEXTcolumns (stored in hidden
BLOBtables by NDB). A
--blob-infooption has been added for this program that causes ndb_desc to generate a report for each subordinate BLOB table. For more information, see ndb_desc — Describe NDB Tables. (Bug #50599)
When one or more data nodes read their LCPs and applied undo logs significantly faster than others, this could lead to a race condition causing system restarts of data nodes to hang. This could most often occur when using both ndbd and ndbmtd processes for the data nodes. (Bug #51644)
When deciding how to divide the REDO log, the
DBDIHkernel block saved more than was needed to restore the previous local checkpoint, which could cause REDO log space to be exhausted prematurely (
NDBerror 410). (Bug #51547)
DML operations can fail with
NDBerror 1220 (REDO log files overloaded...) if the opening and closing of REDO log files takes too much time. If this occurred as a GCI marker was being written in the REDO log while REDO log file 0 was being opened or closed, the error could persist until a GCP stop was encountered. This issue could be triggered when there was insufficient REDO log space (for example, with configuration parameter settings
NoOfFragmentLogFiles = 6and
FragmentLogFileSize = 6M) with a load including a very high number of updates. (Bug #51512)
References: See also: Bug #20904.
During an online upgrade from MySQL Cluster NDB 6.2 to MySQL Cluster NDB 6.3, a sufficiently large amount of traffic with more than 1 DML operation per transaction could lead.an NDB 6.3 data node to crash an NDB 6.2 data node with an internal error in the
DBLOQHkernel block. (Bug #51389)
A side effect of the ndb_restore
--rebuild-indexesoptions is to change the schema versions of indexes. When a mysqld later tried to drop a table that had been restored from backup using one or both of these options, the server failed to detect these changed indexes. This caused the table to be dropped, but the indexes to be left behind, leading to problems with subsequent backup and restore operations. (Bug #51374)
ndb_restore crashed while trying to restore a corrupted backup, due to missing error handling. (Bug #51223)
The ndb_restore message
Successfully created index `PRIMARY`...was directed to
stdout. (Bug #51037)
NoOfReplicasequal to 1 or 2, if data nodes from one node group were restarted 256 times and applications were running traffic such that it would encounter
NDBerror 1204 (Temporary failure, distribution changed), the live node in the node group would crash, causing the cluster to crash as well. The crash occurred only when the error was encountered on the 256th restart; having the error on any previous or subsequent restart did not cause any problems. (Bug #50930)
Disk Data: For a Disk Data tablespace whose extent size was not equal to a whole multiple of 32K, the value of the
FREE_EXTENTScolumn in the
INFORMATION_SCHEMA.FILEStable was smaller than the value of
As part of this fix, the implicit rounding of
NDBCLUSTER(see CREATE TABLESPACE Syntax) is now done explicitly, and the rounded values are used for calculating
INFORMATION_SCHEMA.FILEScolumn values and other purposes. (Bug #49709)
References: See also: Bug #31712.
Disk Data: Once all data files associated with a given tablespace had been dropped, there was no way for MySQL client applications (including the mysql client) to tell that the tablespace still existed. To remedy this problem,
INFORMATION_SCHEMA.FILESnow holds an additional row for each tablespace. (Previously, only the data files in each tablespace were shown.) This row shows
FILE_NAMEcolumn. (Bug #31782)
Disk Data: It was possible to issue a
ALTER TABLESPACEstatement in which
INITIAL_SIZEwas less than
EXTENT_SIZE. (In such cases,
INFORMATION_SCHEMA.FILESerroneously reported the value of the
1and that of the
0.) Now when either of these statements is issued such that
INITIAL_SIZEis less than
EXTENT_SIZE, the statement fails with an appropriate error message. (Bug #31712)
References: See also: Bug #49709.
Cluster API: An issue internal to ndb_mgm could cause problems when trying to start a large number of data nodes at the same time. (Bug #51273)
References: See also: Bug #51310.
IndexMemorygreater than 2GB could cause data nodes to crash while starting. (Bug #51256)
An initial restart of a data node configured with a large amount of memory could fail with a Pointer too large error. (Bug #51027)
References: This issue is a regression of: Bug #47818.
Functionality Added or Changed
Important Change: The maximum permitted value of the
ndb_autoincrement_prefetch_szsystem variable has been increased from 256 to 65536. (Bug #50621)
BuildIndexThreadsgreater than 1 with more than 31 ordered indexes caused node and system restarts to fail. (Bug #50266)
Dropping unique indexes in parallel while they were in use could cause node and cluster failures. (Bug #50118)
When setting the
LockPagesInMainMemoryconfiguration parameter failed, only the error Failed to memlock pages... was returned. Now in such cases the operating system's error code is also returned. (Bug #49724)
If a query on an
NDBtable compared a constant string value to a column, and the length of the string was greater than that of the column, condition pushdown did not work correctly. (The string was truncated to fit the column length before being pushed down.) Now in such cases, the condition is no longer pushed down. (Bug #49459)
Performing intensive inserts and deletes in parallel with a high scan load could a data node crashes due to a failure in the
DBACCkernel block. This was because checking for when to perform bucket splits or merges considered the first 4 scans only. (Bug #48700)
During Start Phases 1 and 2, the
STATUScommand sometimes (falsely) returned
Not Connectedfor data nodes running ndbmtd. (Bug #47818)
mysqld could sometimes crash during a commit while trying to handle NDB Error 4028 Node failure caused abort of transaction. (Bug #38577)
LockPagesInMainMemory, the stated memory was not allocated when the node was started, but rather only when the memory was used by the data node process for other reasons. (Bug #37430)
Trying to insert more rows than would fit into an
NDBtable caused data nodes to crash. Now in such situations, the insert fails gracefully with error 633 Table fragment hash index has reached maximum possible size. (Bug #34348)
Disk Data: When a crash occurs due to a problem in Disk Data code, the currently active page list is printed to
stdout(that is, in one or more
ndb_files). One of these lists could contain an endless loop; this caused a printout that was effectively never-ending. Now in such cases, a maximum of 512 entries is printed from each list. (Bug #42431)
Functionality Added or Changed
Added multi-threaded ordered index building capability during system restarts or node restarts, controlled by the
BuildIndexThreadsdata node configuration parameter (also introduced in this release).
Functionality Added or Changed
This enhanced functionality is supported for upgrades to MySQL Cluster NDB 7.0 when the
NDBengine version is 7.0.10 or later. (Bug #48528, Bug #49163)
Whether a system restart or a node restart is required when resetting that parameter;
Whether cluster nodes need to be restarted using the
--initialoption when resetting the parameter.
Node takeover during a system restart occurs when the REDO log for one or more data nodes is out of date, so that a node restart is invoked for that node or those nodes. If this happens while a mysqld process is attached to the cluster as an SQL node, the mysqld takes a global schema lock (a row lock), while trying to set up cluster-internal replication.
However, this setup process could fail, causing the global schema lock to be held for an excessive length of time, which made the node restart hang as well. As a result, the mysqld failed to set up cluster-internal replication, which led to tables being read only, and caused one node to hang during the restart.Note
This issue could actually occur in MySQL Cluster NDB 7.0 only, but the fix was also applied MySQL Cluster NDB 6.3, to keep the two codebases in alignment.
If the master data node receiving a request from a newly started API or data node for a node ID died before the request has been handled, the management server waited (and kept a mutex) until all handling of this node failure was complete before responding to any other connections, instead of responding to other connections as soon as it was informed of the node failure (that is, it waited until it had received a NF_COMPLETEREP signal rather than a NODE_FAILREP signal). On visible effect of this misbehavior was that it caused management client commands such as SHOW and ALL STATUS to respond with unnecessary slowness in such circumstances. (Bug #49207)
When evaluating the options
--exclude-tables, the ndb_restore program overwrote the result of the database-level options with the result of the table-level options rather than merging these results together, sometimes leading to unexpected and unpredictable results.
As part of the fix for this problem, the semantics of these options have been clarified; because of this, the rules governing their evaluation have changed slightly. These changes be summed up as follows:
--exclude-*options are now evaluated from right to left in the order in which they are passed to ndb_restore.
--exclude-*options are now cumulative.
In the event of a conflict, the first (rightmost) option takes precedence.
For more detailed information and examples, see ndb_restore — Restore a MySQL Cluster Backup. (Bug #48907)
When performing tasks that generated large amounts of I/O (such as when using ndb_restore), an internal memory buffer could overflow, causing data nodes to fail with signal 6.
Subsequent analysis showed that this buffer was not actually required, so this fix removes it. (Bug #48861)
Exhaustion of send buffer memory or long signal memory caused data nodes to crash. Now an appropriate error message is provided instead when this situation occurs. (Bug #48852)
Under certain conditions, accounting of the number of free scan records in the local query handler could be incorrect, so that during node recovery or a local checkpoint operations, the LQH could find itself lacking a scan record that is expected to find, causing the node to crash. (Bug #48697)
References: See also: Bug #48564.
The creation of an ordered index on a table undergoing DDL operations could cause a data node crash under certain timing-dependent conditions. (Bug #48604)
During an LCP master takeover, when the newly elected master did not receive a
COPY_GCILCP protocol message but other nodes participating in the local checkpoint had received one, the new master could use an uninitialized variable, which caused it to crash. (Bug #48584)
When running many parallel scans, a local checkpoint (which performs a scan internally) could find itself not getting a scan record, which led to a data node crash. Now an extra scan record is reserved for this purpose, and a problem with obtaining the scan record returns an appropriate error (error code 489, Too many active scans). (Bug #48564)
During a node restart, logging was enabled on a per-fragment basis as the copying of each fragment was completed but local checkpoints were not enabled until all fragments were copied, making it possible to run out of redo log file space (
NDBerror code 410) before the restart was complete. Now logging is enabled only after all fragments has been copied, just prior to enabling local checkpoints. (Bug #48474)
--configinfonow indicates that parameters belonging in the
[SHM DEFAULT]sections of the
config.inifile are deprecated or experimental, as appropriate. (Bug #47365)
NDBstores blob column data in a separate, hidden table that is not accessible from MySQL. If this table was missing for some reason (such as accidental deletion of the file corresponding to the hidden table) when making a MySQL Cluster native backup, ndb_restore crashed when attempting to restore the backup. Now in such cases, ndb_restore fails with the error message Table
table_namehas blob column (
column_name) with missing parts table in backup instead. (Bug #47289)
DROP DATABASEfailed when there were stale temporary
NDBtables in the database. This situation could occur if mysqld crashed during execution of a
DROP TABLEstatement after the table definition had been removed from
NDBCLUSTERbut before the corresponding
.ndbfile had been removed from the crashed SQL node's data directory. Now, when mysqld executes
DROP DATABASE, it checks for these files and removes them if there are no corresponding table definitions for them found in
NDBCLUSTER. (Bug #44529)
NDBtable with an excessive number of large
BITcolumns caused the cluster to fail. Now, an attempt to create such a table is rejected with error 791 (Too many total bits in bitfields). (Bug #42046)
References: See also: Bug #42047.
When a long-running transaction lasting long enough to cause Error 410 (REDO log files overloaded) was later committed or rolled back, it could happen that
NDBCLUSTERwas not able to release the space used for the REDO log, so that the error condition persisted indefinitely.
The most likely cause of such transactions is a bug in the application using MySQL Cluster. This fix should handle most cases where this might occur. (Bug #36500)
Disk Data: When running a write-intensive workload with a very large disk page buffer cache, CPU usage approached 100% during a local checkpoint of a cluster containing Disk Data tables. (Bug #49532)
Disk Data: Repeatedly creating and then dropping Disk Data tables could eventually lead to data node failures. (Bug #45794, Bug #48910)
Disk Data: When the
FileSystemPathUndoFilesconfiguration parameter was set to an non-existent path, the data nodes shut down with the generic error code 2341 (Internal program error). Now in such cases, the error reported is error 2815 (File not found).
Cluster API: When a DML operation failed due to a uniqueness violation on an
NDBtable having more than one unique index, it was difficult to determine which constraint caused the failure; it was necessary to obtain an
NdbErrorobject, then decode its
detailsproperty, which in could lead to memory management issues in application code.
To help solve this problem, a new API method
Ndb::getNdbErrorDetail()is added, providing a well-formatted string containing more precise information about the index that caused the unque constraint violation. The following additional changes are also made in the NDB API:
NdbError.detailsis now deprecated in favor of the new method.
Dictionary::listObjects()method has been modified to provide more information.
Cluster API: When using blobs, calling
getBlobHandle()requires the full key to have been set using
getBlobHandle()must access the key for adding blob table operations. However, if
getBlobHandle()was called without first setting all parts of the primary key, the application using it crashed. Now, an appropriate error code is returned instead. (Bug #28116, Bug #48973)
Using a large number of small fragment log files could cause
NDBCLUSTERto crash while trying to read them during a restart. This issue was first observed with 1024 fragment log files of 16 MB each. (Bug #48651)
When the combined length of all names of tables using the
NDBstorage engine was greater than or equal to 1024 bytes, issuing the
START BACKUPcommand in the ndb_mgm client caused the cluster to crash. (Bug #48531)
Functionality Added or Changed
Performance: Significant improvements in redo log handling and other file system operations can yield a considerable reduction in the time required for restarts. While actual restart times observed in a production setting will naturally vary according to database size, hardware, and other conditions, our own preliminary testing shows that these optimizations can yield startup times that are faster than those typical of previous MySQL Cluster releases by a factor of 50 or more.
Important Change: The
--with-ndb-port-baseoption for configure did not function correctly, and has been deprecated. Attempting to use this option produces the warning Ignoring deprecated option --with-ndb-port-base.
Beginning with MySQL Cluster NDB 7.1.0, the deprecation warning itself is removed, and the
--with-ndb-port-baseoption is simply handled as an unknown and invalid option if you try to use it. (Bug #47941)
References: See also: Bug #38502.
In certain cases, performing very large inserts on
NDBtables when using ndbmtd caused the memory allocations for ordered or unique indexes (or both) to be exceeded. This could cause aborted transactions and possibly lead to data node failures. (Bug #48037)
References: See also: Bug #48113.
UPDATE IGNOREstatements, batching of updates is now disabled. This is because such statements failed when batching of updates was employed if any updates violated a unique constraint, to the fact a unique constraint violation could not be handled without aborting the transaction. (Bug #48036)
Starting a data node with a very large amount of
DataMemory(approximately 90G or more) could lead to crash of the node due to job buffer congestion. (Bug #47984)
For example, consider the table created and populated using these statements:
CREATE TABLE t1 ( c1 INT NOT NULL, c2 INT NOT NULL, PRIMARY KEY(c1), KEY(c2) ) ENGINE = NDB; INSERT INTO t1 VALUES(1, 1);
UPDATEstatements, even though they did not change any rows, each still matched a row, but this was reported incorrectly in both cases, as shown here:
UPDATE t1 SET c2 = 1 WHERE c1 = 1;Query OK, 0 rows affected (0.00 sec) Rows matched: 0 Changed: 0 Warnings: 0 mysql>
UPDATE t1 SET c1 = 1 WHERE c2 = 1;Query OK, 0 rows affected (0.00 sec) Rows matched: 0 Changed: 0 Warnings: 0
Now in such cases, the number of rows matched is correct. (In the case of each of the example
UPDATEstatements just shown, this is displayed as Rows matched: 1, as it should be.)
This issue could affect
UPDATEstatements involving any indexed columns in
NDBtables, regardless of the type of index (including
UNIQUE KEY, and
PRIMARY KEY) or the number of columns covered by the index. (Bug #47955)
On Solaris, shutting down a management node failed when issuing the command to do so from a client connected to a different management node. (Bug #47948)
FragmentLogFileSizeto a value greater than 256 MB led to errors when trying to read the redo log file. (Bug #47908)
SHOW CREATE TABLEdid not display the
AUTO_INCREMENTcolumns. (Bug #47865)
Under some circumstances, when a scan encountered an error early in processing by the
DBTCkernel block (see The DBTC Block), a node could crash as a result. Such errors could be caused by applications sending incorrect data, or, more rarely, by a
DROP TABLEoperation executed in parallel with a scan. (Bug #47831)
When starting a node and synchronizing tables, memory pages were allocated even for empty fragments. In certain situations, this could lead to insufficient memory. (Bug #47782)
A very small race-condition between
LQH_TRANSREQsignals when handling node failure could lead to operations (locks) not being taken over when they should have been, and subsequently becoming stale. This could lead to node restart failures, and applications getting into endless lock-conflicts with operations that were not released until the node was restarted. (Bug #47715)
References: See also: Bug #41297.
configure failed to honor the
--with-zlib-diroption when trying to build MySQL Cluster from source. (Bug #47223)
ndbd was not built correctly when compiled using gcc 4.4.0. (The ndbd binary was built, but could not be started.) (Bug #46113)
If a node failed while sending a fragmented long signal, the receiving node did not free long signal assembly resources that it had allocated for the fragments of the long signal that had already been received. (Bug #44607)
When starting a cluster with a great many tables, it was possible for MySQL client connections as well as the slave SQL thread to issue DML statements against MySQL Cluster tables before mysqld had finished connecting to the cluster and making all tables writeable. This resulted in Table ... is read only errors for clients and the Slave SQL thread.
This issue is fixed by introducing the
--ndb-wait-setupoption for the MySQL server. This provides a configurable maximum amount of time that mysqld waits for all
NDBtables to become writeable, before enabling MySQL clients or the slave SQL thread to connect. (Bug #40679)
References: See also: Bug #46955.
When building MySQL Cluster, it was possible to configure the build using
--with-ndb-portwithout supplying a port number. Now in such cases, configure fails with an error. (Bug #38502)
References: See also: Bug #47941.
When the MySQL server SQL mode included
STRICT_TRANS_TABLES, storage engine warnings and error codes specific to
NDBwere returned when errors occurred, instead of the MySQL server errors and error codes expected by some programming APIs (such as Connector/J) and applications. (Bug #35990)
When a copying operation exhausted the available space on a data node while copying large
BLOBcolumns, this could lead to failure of the data node and a Table is full error on the SQL node which was executing the operation. Examples of such operations could include an
ALTER TABLEthat changed an
INTcolumn to a
BLOBcolumn, or a bulk insert of
BLOBdata that failed due to running out of space or to a duplicate key error. (Bug #34583, Bug #48040)
References: See also: Bug #41674, Bug #45768.
Disk Data: A local checkpoint of an empty fragment could cause a crash during a system restart which was based on that LCP. (Bug #47832)
References: See also: Bug #41915.
Cluster API: If an NDB API program reads the same column more than once, it is possible exceed the maximum permissible message size, in which case the operation should be aborted due to NDB error 880 Tried to read too much - too many getValue calls, however due to a change introduced in MySQL Cluster NDB 6.3.18, the check for this was not done correctly, which instead caused a data node crash. (Bug #48266)
Cluster API: The NDB API methods
NdbOperation::getErrorLine()formerly had both
constvariants. The non-
constversions of these methods have been removed. In addition, the
NdbOperation::getBlobHandle()method has been re-implemented to provide consistent internal semantics. (Bug #47798)
Cluster API: A duplicate read of a column caused NDB API applications to crash. (Bug #45282)
Cluster API: The error handling shown in the example file
ndbapi_scan.cppincluded with the MySQL Cluster distribution was incorrect. (Bug #39573)
The disconnection of an API or SQL node having a node ID greater than 49 caused a forced shutdown of the cluster. (Bug #47844)
The error message text for
NDBerror code 410 (REDO log files overloaded...) was truncated. (Bug #23662)
Functionality Added or Changed
Disk Data: Two new columns have been added to the output of ndb_desc to make it possible to determine how much of the disk space allocated to a given table or fragment remains free. (This information is not available from the
INFORMATION_SCHEMA.FILEStable, since the
FILEStable applies only to Disk Data files.) For more information, see ndb_desc — Describe NDB Tables. (Bug #47131)
mysqld allocated an excessively large buffer for handling
BLOBvalues due to overestimating their size. (For each row, enough space was allocated to accommodate every
TEXTcolumn value in the result set.) This could adversely affect performance when using tables containing
TEXTcolumns; in a few extreme cases, this issue could also cause the host system to run out of memory unexpectedly. (Bug #47574)
References: See also: Bug #47572, Bug #47573.
When an instance of the
NDBCLUSTERtable handler was recycled (this can happen due to table definition cache pressure or to operations such as
ALTER TABLE), if the last row read contained blobs of zero length, the buffer was not freed, even though the reference to it was lost. This resulted in a memory leak.
For example, consider the table defined and populated as shown here:
CREATE TABLE t (a INT PRIMARY KEY, b LONGTEXT) ENGINE=NDB; INSERT INTO t VALUES (1, REPEAT('F', 20000)); INSERT INTO t VALUES (2, '');
SELECT a, length(b) FROM bl ORDER BY a; FLUSH TABLES;
Prior to the fix, this resulted in a memory leak proportional to the size of the stored
LONGTEXTvalue each time these two statements were executed. (Bug #47573)
References: See also: Bug #47572, Bug #47574.
Large transactions involving joins between tables containing
BLOBcolumns used excessive memory. (Bug #47572)
References: See also: Bug #47573, Bug #47574.
A variable was left uninitialized while a data node copied data from its peers as part of its startup routine; if the starting node died during this phase, this could lead a crash of the cluster when the node was later restarted. (Bug #47505)
When a data node restarts, it first runs the redo log until reaching the latest restorable global checkpoint; after this it scans the remainder of the redo log file, searching for entries that should be invalidated so they are not used in any subsequent restarts. (It is possible, for example, if restoring GCI number 25, that there might be entries belonging to GCI 26 in the redo log.) However, under certain rare conditions, during the invalidation process, the redo log files themselves were not always closed while scanning ahead in the redo log. In rare cases, this could lead to
MaxNoOfOpenFilesbeing exceeded, causing a the data node to crash. (Bug #47171)
For very large values of
MaxNoOfAttributes, the calculation for
StringMemorycould overflow when creating large numbers of tables, leading to
NDBerror 773 (Out of string memory, please modify StringMemory config parameter), even when
StringMemorywas set to
100(100 percent). (Bug #47170)
The default value for the
StringMemoryconfiguration parameter, unlike other MySQL Cluster configuration parameters, was not set in
ndb/src/mgmsrv/ConfigInfo.cpp. (Bug #47166)
Signals from a failed API node could be received after an
API_FAILREQsignal (see Operations and Signals) has been received from that node, which could result in invalid states for processing subsequent signals. Now, all pending signals from a failing API node are processed before any
API_FAILREQsignal is received. (Bug #47039)
References: See also: Bug #44607.
Using triggers on
ndb_autoincrement_prefetch_szto be treated as having the NDB kernel's internal default value (32) and the value for this variable as set on the cluster's SQL nodes to be ignored. (Bug #46712)
When performing auto-discovery of tables on individual SQL nodes,
NDBCLUSTERattempted to overwrite existing
.frmfiles and corrupted them.
Workaround. In the mysql client, create a new table (
t2) with same definition as the corrupted table (
t1). Use your system shell or file manager to rename the old
.MYDfile to the new file name (for example, mv t1.MYD t2.MYD). In the mysql client, repair the new table, drop the old one, and rename the new table using the old file name (for example,
RENAME TABLE t2 TO t1).
Running ndb_restore with the
--print_logoption could cause it to crash. (Bug #40428, Bug #33040)
An insert on an
NDBtable was not always flushed properly before performing a scan. One way in which this issue could manifest was that
LAST_INSERT_ID()sometimes failed to return correct values when using a trigger on an
NDBtable. (Bug #38034)
When a data node received a
TAKE_OVERTCCONFsignal from the master before that node had received a
NODE_FAILREP, a race condition could in theory result. (Bug #37688)
References: See also: Bug #25364, Bug #28717.
Some joins on large
BLOBcolumns could cause mysqld processes to leak memory. The joins did not need to reference the
BLOBcolumns directly for this issue to occur. (Bug #36701)
On Mac OS X 10.5, commands entered in the management client failed and sometimes caused the client to hang, although management client commands invoked using the
-e) option from the system shell worked normally.
For example, the following command failed with an error and hung until killed manually, as shown here:
SHOWWarning, event thread startup failed, degraded printouts as result, errno=36
However, the same management client command, invoked from the system shell as shown here, worked correctly:
ndb_mgm -e "SHOW"
References: See also: Bug #34438.
Disk Data: Calculation of free space for Disk Data table fragments was sometimes done incorrectly. This could lead to unnecessary allocation of new extents even when sufficient space was available in existing ones for inserted data. In some cases, this might also lead to crashes when restarting data nodes.Note
This miscalculation was not reflected in the contents of the
INFORMATION_SCHEMA.FILEStable, as it applied to extents allocated to a fragment, and not to a file.
Cluster API: In some circumstances, if an API node encountered a data node failure between the creation of a transaction and the start of a scan using that transaction, then any subsequent calls to
closeTransaction()could cause the same transaction to be started and closed repeatedly. (Bug #47329)
Cluster API: Performing multiple operations using the same primary key within the same
NdbTransaction::execute()call could lead to a data node crash.Note
This fix does not make change the fact that performing multiple operations using the same primary key within the same
execute()is not supported; because there is no way to determine the order of such operations, the result of such combined operations remains undefined.
References: See also: Bug #44015.
Functionality Added or Changed
On Solaris platforms, the MySQL Cluster management server and NDB API applications now use
CLOCK_REALTIMEas the default clock. (Bug #46183)
A new option
--exclude-missing-columnshas been added for the ndb_restore program. In the event that any tables in the database or databases being restored to have fewer columns than the same-named tables in the backup, the extra columns in the backup's version of the tables are ignored. For more information, see ndb_restore — Restore a MySQL Cluster Backup. (Bug #43139)
This issue, originally resolved in MySQL 5.1.16, re-occurred due to a later (unrelated) change. The fix has been re-applied.
Restarting the cluster following a local checkpoint and an online
ALTER TABLEon a non-empty table caused data nodes to crash. (Bug #46651)
Full table scans failed to execute when the cluster contained more than 21 table fragments.Note
The number of table fragments in the cluster can be calculated as the number of data nodes, times 8 (that is, times the value of the internal constant
MAX_FRAG_PER_NODE), divided by the number of replicas. Thus, when
NoOfReplicas = 1at least 3 data nodes were required to trigger this issue, and when
NoOfReplicas = 2at least 4 data nodes were required to do so.
Killing MySQL Cluster nodes immediately following a local checkpoint could lead to a crash of the cluster when later attempting to perform a system restart.
The exact sequence of events causing this issue was as follows:
Local checkpoint occurs.
Immediately following the LCP, kill the master data node.
Kill the remaining data nodes within a few seconds of killing the master.
Attempt to restart the cluster.
Ending a line in the
config.inifile with an extra semicolon character (
;) caused reading the file to fail with a parsing error. (Bug #46242)
When combining an index scan and a delete with a primary key delete, the index scan and delete failed to initialize a flag properly. This could in rare circumstances cause a data node to crash. (Bug #46069)
AutoReconnectconfiguration parameter for API nodes (including SQL nodes) has been added. This is intended to prevent API nodes from re-using allocated node IDs during cluster restarts. For more information, see Defining SQL and Other API Nodes in a MySQL Cluster.
The signals used by ndb_restore to send progress information about backups to the cluster log accessed the cluster transporter without using any locks. Because of this, it was theoretically possible that these signals could be interefered with by heartbeat signals if both were sent at the same time, causing the ndb_restore messages to be corrupted. (Bug #45646)
Problems could arise when using
VARCHARcolumns whose size was greater than 341 characters and which used the
utf8_unicode_cicollation. In some cases, this combination of conditions could cause certain queries and
OPTIMIZE TABLEstatements to crash mysqld. (Bug #45053)
An internal NDB API buffer was not properly initialized. (Bug #44977)
When a data node had written its GCI marker to the first page of a megabyte, and that node was later killed during restart after having processed that page (marker) but before completing a LCP, the data node could fail with file system errors. (Bug #44952)
References: See also: Bug #42564, Bug #44291.
The warning message Possible bug in Dbdih::execBLOCK_COMMIT_ORD ... could sometimes appear in the cluster log. This warning is obsolete, and has been removed. (Bug #44563)
If the cluster crashed during the execution of a
CREATE LOGFILE GROUPstatement, the cluster could not be restarted afterward. (Bug #36702)
References: See also: Bug #34102.
Partitioning; Disk Data: An
NDBtable created with a very large value for the
MAX_ROWSoption could—if this table was dropped and a new table with fewer partitions, but having the same table ID, was created—cause ndbd to crash when performing a system restart. This was because the server attempted to examine each partition whether or not it actually existed. (Bug #45154)
References: See also: Bug #58638.
Disk Data: If the value set in the
FileSystemPathUndoFileswas identical to the value set for
FileSystemPath, that parameter was ignored when starting the data node with
--initialoption. As a result, the Disk Data files in the corresponding directory were not removed when performing an initial start of the affected data node or data nodes. (Bug #46243)
Disk Data: During a checkpoint, restore points are created for both the on-disk and in-memory parts of a Disk Data table. Under certain rare conditions, the in-memory restore point could include or exclude a row that should have been in the snapshot. This would later lead to a crash during or following recovery. (Bug #41915)
References: See also: Bug #47832.
Functionality Added or Changed
Two new server status variables
Ndb_pruned_scan_counthave been introduced.
Ndb_scan_countgives the number of scans executed since the cluster was last started.
Ndb_pruned_scan_countgives the number of scans for which
NDBCLUSTERwas able to use partition pruning. Together, these variables can be used to help determine in the MySQL server whether table scans are pruned by
NDBCLUSTER. (Bug #44153)
The ndb_config utility program can now provide an offline dump of all MySQL Cluster configuration parameters including information such as default and permitted values, brief description, and applicable section of the
config.inifile. A dump in text format is produced when running ndb_config with the new
--configinfooption, and in XML format when the options
--configinfo --xmlare used together. For more information and examples, see ndb_config — Extract MySQL Cluster Configuration Information.
Important Change; Partitioning: User-defined partitioning of an
NDBCLUSTERtable without any primary key sometimes failed, and could cause mysqld to crash.
Now, if you wish to create an
NDBCLUSTERtable with user-defined partitioning, the table must have an explicit primary key, and all columns listed in the partitioning expression must be part of the primary key. The hidden primary key used by the
NDBCLUSTERstorage engine is not sufficient for this purpose. However, if the list of columns is empty (that is, the table is defined using
PARTITION BY [LINEAR] KEY()), then no explicit primary key is required.
This change does not effect the partitioning of tables using any storage engine other than
NDBCLUSTER. (Bug #40709)
pkginstaller for MySQL Cluster on Solaris did not perform a complete installation due to an invalid directory reference in the postinstall script. (Bug #41998)
When ndb_config could not find the file referenced by the
--config-fileoption, it tried to read
my.cnfinstead, then failed with a misleading error message. (Bug #44846)
When a data node was down so long that its most recent local checkpoint depended on a global checkpoint that was no longer restorable, it was possible for it to be unable to use optimized node recovery when being restarted later. (Bug #44844)
References: See also: Bug #26913.
--xmldid not output any entries for the
HostNameparameter. In addition, the default listed for
MaxNoOfFileswas outside the permitted range of values. (Bug #44749)
References: See also: Bug #44685, Bug #44746.
The output of ndb_config
--xmldid not provide information about all sections of the configuration file. (Bug #44685)
References: See also: Bug #44746, Bug #44749.
Inspection of the code revealed that several assignment operators (
=) were used in place of comparison operators (
DbdihMain.cpp. (Bug #44567)
References: See also: Bug #44570.
It was possible for NDB API applications to insert corrupt data into the database, which could subquently lead to data node crashes. Now, stricter checking is enforced on input data for inserts and updates. (Bug #44132)
ndb_restore failed when trying to restore data on a big-endian machine from a backup file created on a little-endian machine. (Bug #44069)
ndberror.ccontained a C++-style comment, which caused builds to fail with some C compilers. (Bug #44036)
When trying to use a data node with an older version of the management server, the data node crashed on startup. (Bug #43699)
In some cases, data node restarts during a system restart could fail due to insufficient redo log space. (Bug #43156)
NDBCLUSTERdid not build correctly on Solaris 9 platforms. (Bug #39080)
References: See also: Bug #39036, Bug #39038.
The output of ndbd
--helpdid not provide clear information about the program's
--initial-startoptions. (Bug #28905)
It was theoretically possible for the value of a nonexistent column to be read as
NULL, rather than causing an error. (Bug #27843)
Disk Data: This fix supersedes and improves on an earlier fix made for this bug in MySQL 5.1.18. (Bug #24521)
Cluster Replication: If data node failed during an event creation operation, there was a slight risk that a surviving data node could send an invalid table reference back to NDB, causing the operation to fail with a false Error 723 (No such table). This could take place when a data node failed as a mysqld process was setting up MySQL Cluster Replication. (Bug #43754)
Cluster API: Partition pruning did not work correctly for queries involving multiple range scans.
As part of the fix for this issue, several improvements have been made in the NDB API, including the addition of a new
NdbScanOperation::getPruned()method, a new variant of
NdbIndexScanOperation::setBound(), and a new
PartitionSpecdata structure. (Bug #37934)
TransactionDeadlockDetectionTimeoutvalues less than 100 were treated as 100. This could cause scans to time out unexpectedly. (Bug #44099)
A race condition could occur when a data node failed to restart just before being included in the next global checkpoint. This could cause other data nodes to fail. (Bug #43888)
TimeBetweenLocalCheckpointswas measured from the end of one local checkpoint to the beginning of the next, rather than from the beginning of one LCP to the beginning of the next. This meant that the time spent performing the LCP was not taken into account when determining the
TimeBetweenLocalCheckpointsinterval, so that LCPs were not started often enough, possibly causing data nodes to run out of redo log space prematurely. (Bug #43567)
Using indexes containing variable-sized columns could lead to internal errors when the indexes were being built. (Bug #43226)
When a data node process had been killed after allocating a node ID, but before making contact with any other data node processes, it was not possible to restart it due to a node ID allocation failure.
This issue could effect either ndbd or ndbmtd processes. (Bug #43224)
References: This issue is a regression of: Bug #42973.
Some queries using combinations of logical and comparison operators on an indexed column in the
WHEREclause could fail with the error Got error 4541 'IndexBound has no bound information' from NDBCLUSTER. (Bug #42857)
ndb_restore crashed when trying to restore a backup made to a MySQL Cluster running on a platform having different endianness from that on which the original backup was taken. (Bug #39540)
When aborting an operation involving both an insert and a delete, the insert and delete were aborted separately. This was because the transaction coordinator did not know that the operations affected on same row, and, in the case of a committed-read (tuple or index) scan, the abort of the insert was performed first, then the row was examined after the insert was aborted but before the delete was aborted. In some cases, this would leave the row in a inconsistent state. This could occur when a local checkpoint was performed during a backup. This issue did not affect primary ley operations or scans that used locks (these are serialized).
After this fix, for ordered indexes, all operations that follow the operation to be aborted are now also aborted.
Disk Data: When a log file group had an undo log file whose size was too small, restarting data nodes failed with Read underflow errors.
As a result of this fix, the minimum permitted
INTIAL_SIZEfor an undo log file is now
1M(1 megabyte). (Bug #29574)
Cluster API: If the largest offset of a
RecordSpecificationused for an
NdbRecordobject was for the
NULLbits (and thus not a column), this offset was not taken into account when calculating the size used for the
RecordSpecification. This meant that the space for the
NULLbits could be overwritten by key or other information. (Bug #43891)
BITcolumns created using the native NDB API format that were not created as nullable could still sometimes be overwritten, or cause other columns to be overwritten.
This issue did not effect tables having
BITcolumns created using the mysqld format (always used by MySQL Cluster SQL nodes). (Bug #43802)
Cluster API: When performing insert or write operations,
NdbRecordpermits key columns to be specified in both the key record and in the attribute record. Only one key column value for each key column should be sent to the NDB kernel, but this was not guaranteed. This is now ensured as follows: For insert and write operations, key column values are taken from the key record; for scan takeover update operations, key column values are taken from the attribute record. (Bug #42238)
Cluster API: Ordered index scans using
NdbRecordformerly expressed a
BoundEQrange as separate lower and upper bounds, resulting in 2 copies of the column values being sent to the NDB kernel.
Now, when a range is specified by
NdbIndexScanOperation::setBound(), the passed pointers, key lengths, and inclusive bits are compared, and only one copy of the equal key columns is sent to the kernel. This makes such operations more efficient, as half the amount of
KeyInfois now sent for a
BoundEQrange as before. (Bug #38793)
Functionality Added or Changed
A new data node configuration parameter
MaxLCPStartDelayhas been introduced to facilitate parallel node recovery by causing a local checkpoint to be delayed while recovering nodes are synchronizing data dictionaries and other meta-information. For more information about this parameter, see Defining MySQL Cluster Data Nodes. (Bug #43053)
Performance: Updates of the
SYSTAB_0system table to obtain a unique identifier did not use transaction hints for tables having no primary key. In such cases the NDB kernel used a cache size of 1. This meant that each insert into a table not having a primary key required an update of the corresponding
SYSTAB_0entry, creating a potential performance bottleneck.
With this fix, inserts on
NDBtables without primary keys can be under some conditions be performed up to 100% faster than previously. (Bug #39268)
Packaging: Packages for MySQL Cluster were missing the
libndbclient.afiles. (Bug #42278)
ALTER TABLE ... REORGANIZE PARTITIONon an
NDBCLUSTERtable having only one partition caused mysqld to crash. (Bug #41945)
References: See also: Bug #40389.
Backup IDs greater than 231 were not handled correctly, causing negative values to be used in backup directory names and printouts. (Bug #43042)
When using ndbmtd, NDB kernel threads could hang while trying to start the data nodes with
LockPagesInMainMemoryset to 1. (Bug #43021)
When using multiple management servers and starting several API nodes (possibly including one or more SQL nodes) whose connection strings listed the management servers in different order, it was possible for 2 API nodes to be assigned the same node ID. When this happened it was possible for an API node not to get fully connected, consequently producing a number of errors whose cause was not easily recognizable. (Bug #42973)
ndb_error_reporter worked correctly only with GNU tar. (With other versions of tar, it produced empty archives.) (Bug #42753)
NDBCLUSTERtables caused such tables to become locked. (Bug #42751)
References: See also: Bug #16229, Bug #18135.
Given a MySQL Cluster containing no data (that is, whose data nodes had all been started using
--initial, and into which no data had yet been imported) and having an empty backup directory, executing
START BACKUPwith a user-specified backup ID caused the data nodes to crash. (Bug #41031)
In some cases,
NDBdid not check correctly whether tables had changed before trying to use the query cache. This could result in a crash of the debug MySQL server. (Bug #40464)
Disk Data: It was not possible to add an in-memory column online to a table that used a table-level or column-level
STORAGE DISKoption. The same issue prevented
ALTER ONLINE TABLE ... REORGANIZE PARTITIONfrom working on Disk Data tables. (Bug #42549)
Disk Data: Creating a Disk Data tablespace with a very large extent size caused the data nodes to fail. The issue was observed when using extent sizes of 100 MB and larger. (Bug #39096)
Disk Data: Trying to execute a
CREATE LOGFILE GROUPstatement using a value greater than
UNDO_BUFFER_SIZEcaused data nodes to crash.
As a result of this fix, the upper limit for
600M; attempting to set a higher value now fails gracefully with an error. (Bug #34102)
References: See also: Bug #36702.
Disk Data: When attempting to create a tablespace that already existed, the error message returned was Table or index with given name already exists. (Bug #32662)
Disk Data: Using a path or file name longer than 128 characters for Disk Data undo log files and tablespace data files caused a number of issues, including failures of
CREATE LOGFILE GROUP,
ALTER LOGFILE GROUP,
CREATE TABLESPACE, and
ALTER TABLESPACEstatements, as well as crashes of management nodes and data nodes.
With this fix, the maximum length for path and file names used for Disk Data undo log files and tablespace data files is now the same as the maximum for the operating system. (Bug #31769, Bug #31770, Bug #31772)
Disk Data: Attempting to perform a system restart of the cluster where there existed a logfile group without and undo log files caused the data nodes to crash.Note
While issuing a
CREATE LOGFILE GROUPstatement without an
ADD UNDOFILEoption fails with an error in the MySQL server, this situation could arise if an SQL node failed during the execution of a valid
CREATE LOGFILE GROUPstatement; it is also possible to create a logfile group without any undo log files using the NDB API.
Cluster API: Some error messages from ndb_mgmd contained newline (
\n) characters. This could break the MGM API protocol, which uses the newline as a line separator. (Bug #43104)
Cluster API: When using an ordered index scan without putting all key columns in the read mask, this invalid use of the NDB API went undetected, which resulted in the use of uninitialized memory. (Bug #42591)
Functionality Added or Changed
New options are introduced for ndb_restore for determining which tables or databases should be restored:
--include-databasescan be used to restore specific tables or databases.
--exclude-databasescan be used to exclude the specified tables or databases from being restored.
For more information about these options, see ndb_restore — Restore a MySQL Cluster Backup. (Bug #40429)
Disk Data: It is now possible to specify default locations for Disk Data data files and undo log files, either together or separately, using the data node configuration parameters
FileSystemPathUndoFiles. For information about these configuration parameters, see Disk Data file system parameters.
It is also now possible to specify a log file group, tablespace, or both, that is created when the cluster is started, using the
InitialTablespacedata node configuration parameters. For information about these configuration parameters, see Disk Data object creation parameters.
When performing more than 32 index or tuple scans on a single fragment, the scans could be left hanging. This caused unnecessary timeouts, and in addition could possibly lead to a hang of an LCP. (Bug #42559)
References: This issue is a regression of: Bug #42084.
A data node failure that occurred between calls to
NdbTransaction::execute()was not correctly handled; a subsequent call to
nextResult()caused a null pointer to be deferenced, leading to a segfault in mysqld. (Bug #42545)
SHOW GLOBAL STATUS LIKE 'NDB%'before mysqld had connected to the cluster caused a segmentation fault. (Bug #42458)
Data node failures that occurred before all data nodes had connected to the cluster were not handled correctly, leading to additional data node failures. (Bug #42422)
When a cluster backup failed with Error 1304 (Node
node_id1: Backup request from
node_id2failed to start), no clear reason for the failure was provided.
As part of this fix, MySQL Cluster now retries backups in the event of sequence errors. (Bug #42354)
References: See also: Bug #22698.
SHOW ENGINE NDBCLUSTER STATUSon an SQL node before the management server had connected to the cluster caused mysqld to crash. (Bug #42264)
Functionality Added or Changed
Important Change: Formerly, when the management server failed to create a transporter for a data node connection,
net_write_timeoutseconds elapsed before the data node was actually permitted to disconnect. Now in such cases the disconnection occurs immediately. (Bug #41965)
References: See also: Bug #41713.
It is now possible while in Single User Mode to restart all data nodes using
ALL RESTARTin the management client. Restarting of individual nodes while in Single User Mode remains not permitted. (Bug #31056)
Formerly, when using MySQL Cluster Replication, records for “empty” epochs—that is, epochs in which no changes to
NDBCLUSTERdata or tables took place—were inserted into the
ndb_binlog_indextables on the slave even when
--log-slave-updateswas disabled. Beginning with MySQL Cluster NDB 6.2.16 and MySQL Cluster NDB 6.3.13 this was changed so that these “empty” epochs were no longer logged. However, it is now possible to re-enable the older behavior (and cause “empty” epochs to be logged) by using the
--ndb-log-empty-epochsoption. For more information, see Replication Slave Options and Variables.
References: See also: Bug #37472.
A maximum of 11
TUPscans were permitted in parallel. (Bug #42084)
Trying to execute an
ALTER ONLINE TABLE ... ADD COLUMNstatement while inserting rows into the table caused mysqld to crash. (Bug #41905)
If the master node failed during a global checkpoint, it was possible in some circumstances for the new master to use an incorrect value for the global checkpoint index. This could occur only when the cluster used more than one node group. (Bug #41469)
API nodes disconnected too agressively from cluster when data nodes were being restarted. This could sometimes lead to the API node being unable to access the cluster at all during a rolling restart. (Bug #41462)
It was not possible to perform online upgrades from a MySQL Cluster NDB 6.2 release to MySQL Cluster NDB 6.3.8 or a later MySQL Cluster NDB 6.3 release. (Bug #41435)
Cluster log files were opened twice by internal log-handling code, resulting in a resource leak. (Bug #41362)
A race condition in transaction coordinator takeovers (part of node failure handling) could lead to operations (locks) not being taken over and subsequently getting stale. This could lead to subsequent failures of node restarts, and to applications getting into an endless lock conflict with operations that would not complete until the node was restarted. (Bug #41297)
References: See also: Bug #41295.
An abort path in the
DBLQHkernel block failed to release a commit acknowledgment marker. This meant that, during node failure handling, the local query handler could be added multiple times to the marker record which could lead to additional node failures due an array overflow. (Bug #41296)
During node failure handling (of a data node other than the master), there was a chance that the master was waiting for a
GCP_NODEFINISHEDsignal from the failed node after having received it from all other data nodes. If this occurred while the failed node had a transaction that was still being committed in the current epoch, the master node could crash in the
DBTCkernel block when discovering that a transaction actually belonged to an epoch which was already completed. (Bug #41295)
EXITin the management client sometimes caused the client to hang. (Bug #40922)
In the event that a MySQL Cluster backup failed due to file permissions issues, conflicting reports were issued in the management client. (Bug #34526)
If all data nodes were shut down, MySQL clients were unable to access
NDBCLUSTERtables and data even after the data nodes were restarted, unless the MySQL clients themselves were restarted. (Bug #33626)
Disk Data: Starting a cluster under load such that Disk Data tables used most of the undo buffer could cause data node failures.
The fix for this bug also corrected an issue in the
LGMANkernel block where the amount of free space left in the undo buffer was miscalculated, causing buffer overruns. This could cause records in the buffer to be overwritten, leading to problems when restarting data nodes. (Bug #28077)
mgmapi.hcontained constructs which only worked in C++, but not in C. (Bug #27004)
Functionality Added or Changed
Cluster API: Two new
Ndb_cluster_connectionmethods have been added to help in diagnosing problems with NDB API client connections. The
get_latest_error()method tells whether or not the latest connection attempt succeeded; if the attempt failed,
get_latest_error_msg()provides an error message giving the reason.
If a transaction was aborted during the handling of a data node failure, this could lead to the later handling of an API node failure not being completed. (Bug #41214)
SHOW TABLESrepeatedly could cause
NDBCLUSTERtables to be dropped. (Bug #40854)
Statements of the form
UPDATE ... ORDER BY ... LIMITrun against
NDBCLUSTERtables failed to update all matching rows, or failed with the error Can't find record in '
table_name'. (Bug #40081)
Start phase reporting was inconsistent between the management client and the cluster log. (Bug #39667)
Status messages shown in the management client when restarting a management node were inappropriate and misleading. Now, when restarting a management node, the messages displayed are as follows, where
node_idis the management node's node ID:
Shutting down MGM node
node_idfor restart Node
node_idis being restarted ndb_mgm>
Disk Data: This improves on a previous fix for this issue that was made in MySQL Cluster 6.3.8. (Bug #37116)
References: See also: Bug #29186.
Cluster API: When creating a scan using an
NdbScanFilterobject, it was possible to specify conditions against a
BITcolumn, but the correct rows were not returned when the scan was executed.
As part of this fix, 4 new comparison operators have been implemented for use with scans on
For more information about these operators, see The NdbScanFilter::BinaryCondition Type.
Functionality Added or Changed
Important Change; Cluster API: MGM API applications exited without raising any errors if the connection to the management server was lost. The fix for this issue includes two changes:
The MGM API now provides its own
SIGPIPEhandler to catch the “broken pipe” error that occurs when writing to a closed or reset socket. This means that MGM API now behaves the same as NDB API in this regard.
A new function
ndb_mgm_set_ignore_sigpipe()has been added to the MGM API. This function makes it possible to bypass the
SIGPIPEhandler provided by the MGM API.
When performing an initial start of a data node, fragment log files were always created sparsely—that is, not all bytes were written. Now it is possible to override this behavior using the new
InitFragmentLogFilesconfiguration parameter. (Bug #40847)
Cluster API: Failed operations on
TEXTcolumns were not always reported correctly to the originating SQL node. Such errors were sometimes reported as being due to timeouts, when the actual problem was a transporter overload due to insufficient buffer space. (Bug #39867, Bug #39879)
Undo logs and data files were created in 32K increments. Now these files are created in 512K increments, resulting in shorter creation times. (Bug #40815)
Redo log creation was very slow on some platforms, causing MySQL Cluster to start more slowly than necessary with some combinations of hardware and operating system. This was due to all write operations being synchronized to disk while creating a redo log file. Now this synchronization occurs only after the redo log has been created. (Bug #40734)
Transaction failures took longer to handle than was necessary.
When a data node acting as transaction coordinator (TC) failed, the surviving data nodes did not inform the API node initiating the transaction of this until the failure had been processed by all protocols. However, the API node needed only to know about failure handling by the transaction protocol—that is, it needed to be informed only about the TC takeover process. Now, API nodes (including MySQL servers acting as cluster SQL nodes) are informed as soon as the TC takeover is complete, so that it can carry on operating more quickly. (Bug #40697)
It was theoretically possible for stale data to be read from
NDBCLUSTERtables when the transaction isolation level was set to
ReadCommitted. (Bug #40543)
SET SESSION ndb_optimized_node_selection = 1failed with an invalid warning message. (Bug #40457)
A restarting data node could fail with an error in the
DBDIHkernel block when a local or global checkpoint was started or triggered just as the node made a request for data from another data node. (Bug #40370)
Restoring a MySQL Cluster from a dump made using mysqldump failed due to a spurious error: Can't execute the given command because you have active locked tables or an active transaction. (Bug #40346)
O_DIRECTwas incorrectly disabled when making MySQL Cluster backups. (Bug #40205)
Heavy DDL usage caused the mysqld processes to hang due to a timeout error (
NDBerror code 266). (Bug #39885)
Events logged after setting
ALL CLUSTERLOG STATISTICS=15in the management client did not always include the node ID of the reporting node. (Bug #39839)
A segfault in
Logger::Logcaused ndbd to hang indefinitely. This fix improves on an earlier one for this issue, first made in MySQL Cluster NDB 6.2.16 and MySQL Cluster NDB 6.3.17. (Bug #39180)
References: See also: Bug #38609.
Memory leaks could occur in handling of strings used for storing cluster metadata and providing output to users. (Bug #38662)
A duplicate key or other error raised when inserting into an
NDBCLUSTERtable caused the current transaction to abort, after which any SQL statement other than a
ROLLBACKfailed. With this fix, the
NDBCLUSTERstorage engine now performs an implicit rollback when a transaction is aborted in this way; it is no longer necessary to issue an explicit
ROLLBACKstatement, and the next statement that is issued automatically begins a new transaction.Note
It remains necessary in such cases to retry the complete transaction, regardless of which statement caused it to be aborted.
References: See also: Bug #47654.
Error messages for
NDBCLUSTERerror codes 1224 and 1227 were missing. (Bug #28496)
Disk Data: Issuing concurrent
CREATE LOGFILE GROUP, or
ALTER LOGFILE GROUPstatements on separate SQL nodes caused a resource leak that led to data node crashes when these statements were used again later. (Bug #40921)
Disk Data: Disk-based variable-length columns were not always handled like their memory-based equivalents, which could potentially lead to a crash of cluster data nodes. (Bug #39645)
O_SYNCwas incorrectly disabled on platforms that do not support
O_DIRECT. This issue was noted on Solaris but could have affected other platforms not having
O_DIRECTcapability. (Bug #34638)
Cluster API: The MGM API reset error codes on management server handles before checking them. This meant that calling an MGM API function with a null handle caused applications to crash. (Bug #40455)
Cluster API: It was not always possible to access parent objects directly from
NdbScanOperationobjects. To alleviate this problem, a new
getNdbOperation()method has been added to
NdbBloband new getNdbTransaction() methods have been added to
NdbScanOperation. In addition, a const variant of
NdbOperation::getErrorLine()is now also available. (Bug #40242)
getBlobHandle()failed when used with incorrect column names or numbers. (Bug #40241)
Cluster API: The MGM API function
ndb_mgm_listen_event()ignored bind addresses.
As part of this fix, it is now possible to specify bind addresses in connection strings. See MySQL Cluster Connection Strings, for more information. (Bug #38473)
Cluster API: The NDB API example programs included in MySQL Cluster source distributions failed to compile. (Bug #37491)
References: See also: Bug #40238.
Functionality Added or Changed
It is no longer a requirement for database autodiscovery that an SQL node already be connected to the cluster at the time that a database is created on another SQL node. It is no longer necessary to issue
CREATE SCHEMA) statements on an SQL node joining the cluster after a database is created for the new SQL node to see the database and any
NDBCLUSTERtables that it contains. (Bug #39612)
Starting the MySQL Server with the
--ndbclusteroption plus an invalid command-line option (for example, using mysqld
--ndbcluster --foobar) caused it to hang while shutting down the binary log thread. (Bug #39635)
Dropping and then re-creating a database on one SQL node caused other SQL nodes to hang. (Bug #39613)
Setting a low value of
MaxNoOfLocalScans(< 100) and performing a large number of (certain) scans could cause the Transaction Coordinator to run out of scan fragment records, and then crash. Now when this resource is exhausted, the cluster returns Error 291 (Out of scanfrag records in TC (increase MaxNoOfLocalScans)) instead. (Bug #39549)
When a transaction included a multi-row insert to an
NDBCLUSTERtable that caused a constraint violation, the transaction failed to roll back. (Bug #39538)
Creating a unique index on an
NDBCLUSTERtable caused a memory leak in the
NDBsubscription manager (
SUMA) which could lead to mysqld hanging, due to the fact that the resource shortage was not reported back to the
NDBkernel correctly. (Bug #39518)
References: See also: Bug #39450.
Embedded libmysqld with
NDBdid not drop table events. (Bug #39450)
Unique identifiers in tables having no primary key were not cached. This fix has been observed to increase the efficiency of
INSERToperations on such tables by as much as 50%. (Bug #39267)
When restarting a data node, an excessively long shutdown message could cause the node process to crash. (Bug #38580)
After a forced shutdown and initial restart of the cluster, it was possible for SQL nodes to retain
.frmfiles corresponding to
NDBCLUSTERtables that had been dropped, and thus to be unaware that these tables no longer existed. In such cases, attempting to re-create the tables using
CREATE TABLE IF NOT EXISTScould fail with a spurious Table ... doesn't exist error. (Bug #37921)
A statement of the form
UPDATEwhere there was no row whose primary key column had the stated
valueappeared to succeed, with the server reporting that 1 row had been changed.
This issue was only known to affect MySQL Cluster NDB 6.3.11 and later NDB 6.3 versions. (Bug #37153)
Packaging: Support for the
InnoDBstorage engine was missing from the GPL source releases. An updated GPL source tarball
mysql-5.1.27-ndb-6.3.17-innodb.tar.gzwhich includes code for building
InnoDBcan be found on the MySQL FTP site.
MgmtSrvr::allocNodeId()left a mutex locked following an Ambiguity for node if %d error. (Bug #39158)
An invalid path specification caused mysql-test-run.pl to fail. (Bug #39026)
During transactional coordinator takeover (directly after node failure), the LQH finding an operation in the
LOG_COMMITstate sent an
LQH_TRANS_CONFsignal twice, causing the TC to fail. (Bug #38930)
An invalid memory access caused the management server to crash on Solaris Sparc platforms. (Bug #38628)
A segfault in
Logger::Logcaused ndbd to hang indefinitely. (Bug #38609)
ndb_mgmd failed to start on older Linux distributions (2.4 kernels) that did not support e-polling. (Bug #38592)
ndb_mgmd sometimes performed unnecessary network I/O with the client. This in combination with other factors led to long-running threads that were attempting to write to clients that no longer existed. (Bug #38563)
ndb_restore failed with a floating point exception due to a division by zero error when trying to restore certain data files. (Bug #38520)
A failed connection to the management server could cause a resource leak in ndb_mgmd. (Bug #38424)
Failure to parse configuration parameters could cause a memory leak in the NDB log parser. (Bug #38380)
NDBCLUSTERtable on one SQL node, caused a trigger on this table to be deleted on another SQL node. (Bug #36658)
Attempting to add a
UNIQUE INDEXtwice to an
NDBCLUSTERtable, then deleting rows from the table could cause the MySQL Server to crash. (Bug #35599)
ndb_restore failed when a single table was specified. (Bug #33801)
GCP_COMMITdid not wait for transaction takeover during node failure. This could cause
GCP_SAVE_REQto be executed too early. This could also cause (very rarely) replication to skip rows. (Bug #30780)
Cluster API: Support for Multi-Range Read index scans using the old API (using, for example,
NdbIndexScanOperation::end_of_bound()) were dropped in MySQL Cluster NDB 6.2. This functionality is restored in MySQL Cluster NDB 6.3 beginning with 6.3.17, but remains unavailable in MySQL Cluster NDB 6.2. Both MySQL Cluster NDB 6.2 and 6.3 support Multi-Range Read scans through the
NdbRecordAPI. (Bug #38791)
Cluster API: The
NdbScanOperation::readTuples()method could be called multiple times without error. (Bug #38717)
Cluster API: Certain Multi-Range Read scans involving
IS NOT NULLcomparisons failed with an error in the
NDBlocal query handler. (Bug #38204)
Cluster API: Problems with the public headers prevented
NDBapplications from being built with warnings turned on. (Bug #38177)
Cluster API: Creating an
NdbScanFilterobject using an
NdbScanOperationobject that had not yet had its
readTuples()method called resulted in a crash when later attempting to use the
NdbScanFilter. (Bug #37986)
Cluster API: Executing an
NdbRecordinterpreted delete created with an
ANYVALUEoption caused the transaction to abort. (Bug #37672)
Functionality Added or Changed
Event buffer lag reports are now written to the cluster log. (Bug #37427)
--no-binlogoption for ndb_restore. When used, this option prevents information being written to SQL node binary logs from the restoration of a cluster backup. (Bug #30452)
Cluster API: Changing the system time on data nodes could cause MGM API applications to hang and the data nodes to crash. (Bug #35607)
Failure of a data node could sometimes cause mysqld to crash. (Bug #37628)
DELETE ... WHEREdeleted the wrong row from the table. (Bug #37516)
If subscription was terminated while a node was down, the epoch was not properly acknowledged by that node. (Bug #37442)
libmysqldfailed to wait for the cluster binary log thread to terminate before exiting. (Bug #37429)
In rare circumstances, a connection followed by a disconnection could give rise to a “stale” connection where the connection still existed but was not seen by the transporter. (Bug #37338)
Cluster API: When some operations succeeded and some failed following a call to
NdbTransaction::execute(Commit, AO_IgnoreOnError), a race condition could cause spurious occurrences of NDB API Error 4011 (Internal error). (Bug #37158)
Cluster API: Creating a table on an SQL node, then starting an NDB API application that listened for events from this table, then dropping the table from an SQL node, prevented data node restarts. (Bug #32949, Bug #37279)
Cluster API: A buffer overrun in
NdbBlob::setValue()caused erroneous results on Mac OS X. (Bug #31284)
In certain rare situations,
ndb_size.plcould fail with the error Can't use string ("
value") as a HASH ref while "strict refs" in use. (Bug #43022)
A fail attempt to create an
NDBtable could in some cases lead to resource leaks or cluster failures. (Bug #37072)
Attempting to create a native backup of
NDBtables having a large number of
NULLcolumns and data could lead to node failures. (Bug #37039)
Checking of API node connections was not efficiently handled. (Bug #36843)
References: See also: Bug #36851.
If the combined total of tables and indexes in the cluster was greater than 4096, issuing
START BACKUPcaused data nodes to fail. (Bug #36044)
Where column values to be compared in a query were of the
NDBCLUSTERpassed a value padded to the full size of the column, which caused unnecessary data to be sent to the data nodes. This also had the effect of wasting CPU and network bandwidth, and causing condition pushdown to be disabled where it could (and should) otherwise have been applied. (Bug #35393)
When dropping a table failed for any reason (such as when in single user mode) then the corresponding
.ndbfile was still removed.
Cluster API: Ordered index scans were not pruned correctly where a partitioning key was specified with an EQ-bound. (Bug #36950)
Cluster API: When an insert operation involving
BLOBdata was attempted on a row which already existed, no duplicate key error was correctly reported and the transaction is incorrectly aborted. In some cases, the existing row could also become corrupted. (Bug #36851)
References: See also: Bug #26756.
ndb_global.h, which was not actually installed, causing the compilation of programs that used
NdbApi.hppto fail. (Bug #35853)
SET GLOBAL ndb_extra_loggingcaused mysqld to crash. (Bug #36547)
A race condition caused by a failure in epoll handling could cause data nodes to fail. (Bug #36537)
Under certain rare circumstances, the failure of the new master node while attempting a node takeover would cause takeover errors to repeat without being resolved. (Bug #36199, Bug #36246, Bug #36247, Bug #36276)
When more than one SQL node connected to the cluster at the same time, creation of the
mysql.ndb_schematable failed on one of them with an explicit Table exists error, which was not necessary. (Bug #35943)
mysqld failed to start after running mysql_upgrade. (Bug #35708)
Notification of a cascading master node failures could sometimes not be transmitted correctly (that is, transmission of the
NF_COMPLETEREPsignal could fail), leading to transactions hanging and timing out (
NDBerror 4012), scans hanging, and failure of the management server process. (Bug #32645)
If an API node disconnected and then reconnected during Start Phase 8, then the connection could be “blocked”—that is, the
QMGRkernel block failed to detect that the API node was in fact connected to the cluster, causing issues with the
NDBSubscription Manager (
NDBerror 1427 (Api node died, when SUB_START_REQ reached node) was incorrectly classified as a schema error rather than a temporary error.
Cluster API: Accessing the debug version of
dlopen()resulted in a segmentation fault. (Bug #35927)
Cluster API: Attempting to pass a nonexistent column name to the
NdbOperationcaused NDB API applications to crash. Now the column name is checked, and an error is returned in the event that the column is not found. (Bug #33747)
Important Change: mysqld_safe now traps Signal 13 (
SIGPIPE) so that this signal no longer kills the MySQL server process. (Bug #33984)
Node or system restarts could fail due an unitialized variable in the
DTUPkernel block. This issue was found in MySQL Cluster NDB 6.3.11. (Bug #35797)
It was not possible to determine the value used for the
--ndb-cluster-connection-pooloption in the mysql client. Now this value is reported as a system status variable. (Bug #35573)
The ndb_waiter utility wrongly calculated timeouts. (Bug #35435)
ndb_restore incorrectly handled some data types when applying log files from backups. (Bug #35343)
In some circumstances, a stopped data node was handled incorrectly, leading to redo log space being exhausted following an initial restart of the node, or an initial or partial restart of the cluster (the wrong CGI might be used in such cases). This could happen, for example, when a node was stopped following the creation of a new table, but before a new LCP could be executed. (Bug #35241)
SELECT ... LIKE ...queries yielded incorrect results when used on
NDBtables. As part of this fix, condition pushdown of such queries has been disabled; re-enabling it is expected to be done as part of a later, permanent fix for this issue. (Bug #35185)
ndb_mgmd reported errors to
STDOUTrather than to
STDERR. (Bug #35169)
Nested Multi-Range Read scans failed when the second Multi-Range Read released the first read's unprocessed operations, sometimes leading to an SQL node crash. (Bug #35137)
In some situations, a problem with synchronizing checkpoints between nodes could cause a system restart or a node restart to fail with Error 630 during restore of TX. (Bug #34756)
References: This issue is a regression of: Bug #34033.
A node failure during an initial node restart followed by another node start could cause the master data node to fail, because it incorrectly gave the node permission to start even if the invalidated node's LCP was still running. (Bug #34702)
When a secondary index on a
DECIMALcolumn was used to retrieve data from an
NDBtable, no results were returned even if the target table had a matched value in the column that was defined with the secondary index. (Bug #34515)
If a data node in one node group was placed in the “not started” state (using
), it was not possible to stop a data node in a different node group. (Bug #34201)
NDBCLUSTERtest failures occurred in builds compiled using icc on IA64 platforms. (Bug #31239)
START BACKUPcommand was issued while ndb_restore was running, the backup being restored could be overwritten. (Bug #26498)
Cluster API: Closing a scan before it was executed caused the application to segfault. (Bug #36375)
Cluster API: Using NDB API applications from older MySQL Cluster versions with
libndbclientfrom newer ones caused the cluster to fail. (Bug #36124)
Cluster API: Some ordered index scans could return tuples out of order. (Bug #35908)
Cluster API: Scans having no bounds set were handled incorrectly. (Bug #35876)
NdbScanFilter::getNdbOperation(), which was inadvertently removed in MySQL Cluster NDB 6.3.11, has been restored. (Bug #35854)
Due to the reduction of the number of local checkpoints from 3 to 2 in MySQL Cluster NDB 6.3.8, a data node using ndbd from MySQL Cluster NDB 6.3.8 or later started using a file system from an earlier version could incorrectly invalidate local checkpoints too early during the startup process, causing the node to fail. (Bug #34596)
Cluster failures could sometimes occur when performing more than three parallel takeovers during node restarts or system restarts. This affected MySQL Cluster NDB 6.3.
xreleases only. (Bug #34445)
Upgrades of a cluster using while a
DataMemorysetting in excess of 16 GB caused data nodes to fail. (Bug #34378)
In certain rare circumstances, a race condition could occur between an aborted insert and a delete leading a data node crash. (Bug #34260)
Multi-table updates using ordered indexes during handling of node failures could cause other data nodes to fail. (Bug #34216)
When configured with
NDBsupport, MySQL failed to compile using gcc 4.3 on 64bit FreeBSD systems. (Bug #34169)
The failure of a DDL statement could sometimes lead to node failures when attempting to execute subsequent DDL statements. (Bug #34160)
When configured with
NDBsupport, MySQL failed to compile on 64bit FreeBSD systems. (Bug #34046)
Statements executing multiple inserts performed poorly on
AUTO_INCREMENTcolumns. (Bug #33534)
The ndb_waiter utility polled ndb_mgmd excessively when obtaining the status of cluster data nodes. (Bug #32025)
References: See also: Bug #32023.
Transaction atomicity was sometimes not preserved between reads and inserts under high loads. (Bug #31477)
Having tables with a great many columns could cause Cluster backups to fail. (Bug #30172)
Disk Data; Cluster Replication: Statements violating unique keys on Disk Data tables (such as attempting to insert
NOT NULLcolumn) could cause data nodes to fail. When the statement was executed from the binary log, this could also result in failure of the slave cluster. (Bug #34118)
Disk Data: Updating in-memory columns of one or more rows of Disk Data table, followed by deletion of these rows and re-insertion of them, caused data node failures. (Bug #33619)
Functionality Added or Changed
Important Change; Cluster API: Because
NDB_LE_MemoryUsage.page_size_kbshows memory page sizes in bytes rather than kilobytes, it has been renamed to
page_size_bytes. The name
page_size_kbis now deprecated and thus subject to removal in a future release, although it currently remains supported for reasons of backward compatibility. See The Ndb_logevent_type Type, for more information about
NDB_LE_MemoryUsage. (Bug #30271)
ndb_restore now supports basic attribute promotion; that is, data from a column of a given type can be restored to a column using a “larger” type. For example, Cluster backup data taken from a
SMALLINTcolumn can be restored to a
For more information, see ndb_restore — Restore a MySQL Cluster Backup.
Now only 2 local checkpoints are stored, rather than 3 as in previous MySQL Cluster versions. This lowers disk space requirements and reduces the size and number of redo log files needed.
The mysqld option
--ndb-batch-sizehas been added. This enables control of the size of batches used for running transactions.
Node recovery can now be done in parallel, rather than sequentially, which can result in much faster recovery times.
NDBtables can now be controlled using the session variables
NDBtables not to be checkpointed to disk.
ndb_table_temporaryhas the same effect; in addition, when
ndb_table_temporaryis used, no
NDBtable schema files are created.
OPTIMIZE TABLEcan now be interrupted. This can be done, for example, by killing the SQL thread performing the
Important Change; Disk Data: It is no longer possible on 32-bit systems to issue statements appearing to create Disk Data log files or data files greater than 4 GB in size. (Trying to create log files or data files larger than 4 GB on 32-bit systems led to unrecoverable data node failures; such statements now fail with
NDBerror 1515.) (Bug #29186)
Replication: The code implementing heartbeats did not check for possible errors in some circumstances; this kept the dump thread hanging while waiting for heartbeats loop even though the slave was no longer connected. (Bug #33332)
High numbers of insert operations, delete operations, or both could cause
NDBerror 899 (Rowid already allocated) to occur unnecessarily. (Bug #34033)
A periodic failure to flush the send buffer by the
NDBTCP transporter could cause a unnecessary delay of 10 ms between operations. (Bug #34005)
DROP TABLEdid not free all data memory. This bug was observed in MySQL Cluster NDB 6.3.7 only. (Bug #33802)
A race condition could occur (very rarely) when the release of a GCI was followed by a data node failure. (Bug #33793)
Some tuple scans caused the wrong memory page to be accessed, leading to invalid results. This issue could affect both in-memory and Disk Data tables. (Bug #33739)
A failure to initialize an internal variable led to sporadic crashes during cluster testing. (Bug #33715)
The server failed to reject properly the creation of an
NDBtable having an unindexed
AUTO_INCREMENTcolumn. (Bug #30417)
The Cluster backup process could not detect when there was no more disk space and instead continued to run until killed manually. Now the backup fails with an appropriate error when disk space is exhausted. (Bug #28647)
It was possible in
config.inito define cluster nodes having node IDs greater than the maximum permitted value. (Bug #28298)
Under some circumstances, a recovering data node did not use its own data, instead copying data from another node even when this was not required. This in effect bypassed the optimized node recovery protocol and caused recovery times to be unnecessarily long. (Bug #26913)
Cluster API: Transactions containing inserts or reads would hang during
NdbTransaction::execute()calls made from NDB API applications built against a MySQL Cluster version that did not support micro-GCPs accessing a later version that supported micro-GCPs. This issue was observed while upgrading from MySQL Cluster NDB 6.1.23 to MySQL Cluster NDB 6.2.10 when the API application built against the earlier version attempted to access a data node already running the later version, even after disabling micro-GCPs by setting
TimeBetweenEpochsequal to 0. (Bug #33895)
Cluster API: When reading a
NdbOperation::getValue(), 12 bytes were written to the buffer rather than the expected 8 bytes. (Bug #33750)
Functionality Added or Changed
Compressed local checkpoints and backups are now supported, resulting in a space savings of 50% or more over uncompressed LCPs and backups. Compression of these can be enabled in the
config.inifile using the two new data node configuration parameters
Only in-memory tables are supported.
OPTIMIZEstill has no effect on Disk Data tables.
Only variable-length columns are supported. However, you can force columns defined using fixed-length data types to be dynamic using the
COLUMN_FORMAToption with a
The performance of
NDBtables can be regulated by adjusting the value of the
It is now possible to cause statements occurring within the same transaction to be run as a batch by setting the session variable
To use this feature,
autocommitmust be disabled.
Partitioning: When partition pruning on an
NDBtable resulted in an ordered index scan spanning only one partition, any descending flag for the scan was wrongly discarded, causing
ORDER BY DESCto be treated as
ORDER BY ASC,
MAX()to be handled incorrectly, and similar problems. (Bug #33061)
When all data and SQL nodes in the cluster were shut down abnormally (that is, other than by using
STOPin the cluster management client), ndb_mgm used excessive amounts of CPU. (Bug #33237)
When using micro-GCPs, if a node failed while preparing for a global checkpoint, the master node would use the wrong GCI. (Bug #32922)
Under some conditions, performing an
ALTER TABLEon an
NDBCLUSTERtable failed with a Table is full error, even when only 25% of
DataMemorywas in use and the result should have been a table using less memory (for example, changing a
VARCHAR(80)). (Bug #32670)
Functionality Added or Changed
The output of the ndb_mgm client
STATUScommands now indicates when the cluster is in single user mode. (Bug #27999)
Unnecessary reads when performing a primary key or unique key update have been reduced, and in some cases, eliminated. (It is almost never necessary to read a record prior to an update, the lone exception to this being when a primary key is updated, since this requires a delete followed by an insert, which must be prepared by reading the record.) Depending on the number of primary key and unique key lookups that are performed per transaction, this can yield a considerable improvement in performance.
In a cluster running in diskless mode and with arbitration disabled, the failure of a data node during an insert operation caused other data node to fail. (Bug #31980)
An insert or update with combined range and equality constraints failed when run against an
NDBtable with the error Got unknown error from NDB. An example of such a statement would be
UPDATE t1 SET b = 5 WHERE a IN (7,8) OR a >= 10;. (Bug #31874)
An error with an
sql/ha_ndbcluster.cccould potentially lead to an infinite loop in case of failure when working with
NDBtables. (Bug #31810)
NDBstorage engine code was not safe for strict-alias optimization in gcc 4.2.1. (Bug #31761)
ndb_restore displayed incorrect backup file version information. This meant (for example) that, when attempting to restore a backup made from a MySQL 5.1.22 cluster to a MySQL Cluster NDB 6.3.3 cluster, the restore process failed with the error Restore program older than backup version. Not supported. Use new restore program. (Bug #31723)
Following an upgrade, ndb_mgmd failed with an ArbitrationError. (Bug #31690)
NDBmanagement client command
provided no output when
node_idwas the node ID of a management or API node. Now, when this occurs, the management client responds with
Node. (Bug #29485)
node_id: is not a data node
DELETEoperations after a data node had been shut down could lead to inconsistent data following a restart of the node. (Bug #26450)
UPDATE IGNOREcould sometimes fail on
NDBtables due to the use of unitialized data when checking for duplicate keys to be ignored. (Bug #25817)
Functionality Added or Changed
Incompatible Change: The
--ndb_optimized_node_selectionstartup option for mysqld now permits a wider range of values and corresponding behaviors for SQL nodes when selecting a transaction coordinator.
You should be aware that the default value and behavior as well as the value type used for this option have changed, and that you may need to update the setting used for this option in your
my.cnffile prior to upgrading mysqld. See Server System Variables, for more information.
It was possible in some cases for a node group to be “lost” due to missed local checkpoints following a system restart. (Bug #31525)
NDBtables having names containing nonalphanumeric characters (such as “
$”) were not discovered correctly. (Bug #31470)
A node failure during a local checkpoint could lead to a subsequent failure of the cluster during a system restart. (Bug #31257)
A cluster restart could sometimes fail due to an issue with table IDs. (Bug #30975)
Transaction timeouts were not handled well in some circumstances, leading to excessive number of transactions being aborted unnecessarily. (Bug #30379)
In some cases, the cluster managment server logged entries multiple times following a restart of ndb_mgmd. (Bug #29565)
--helpdid not display any information about the
-aoption. (Bug #29509)
An interpreted program of sufficient size and complexity could cause all cluster data nodes to shut down due to buffer overruns. (Bug #29390)
The cluster log was formatted inconsistently and contained extraneous newline characters. (Bug #25064)
Functionality Added or Changed
NDBerror codes to MySQL storage engine error codes has been improved. (Bug #28423)
Attempting to restore a backup made on a cluster host using one endian to a machine using the other endian could cause the cluster to fail. (Bug #29674)
The description of the
--helpwas incorrect. (Bug #27683)
Functionality Added or Changed
ADD INDEX, and
DROP INDEXoperations can now be performed explicitly for
NDBtables—that is, without copying or locking of the affected tables—using
ALTER ONLINE TABLE. Indexes can also be created and dropped online using
DROP INDEX, respectively, using the
You can force operations that would otherwise be performed online to be done offline using the
Renaming of tables and columns for
MyISAMtables is performed in place without table copying.
It is now possible to control whether fixed-width or variable-width storage is used for a given column of an
NDBtable by means of the
COLUMN_FORMATspecifier as part of the column's definition in a
It is also possible to control whether a given column of an
NDBtable is stored in memory or on disk, using the
STORAGEspecifier as part of the column's definition in a
For permitted values and other information about
STORAGE, see CREATE TABLE Syntax.
A new cluster management server startup option
--bind-addressmakes it possible to restrict management client connections to ndb_mgmd to a single host and port. For more information, see ndb_mgmd — The MySQL Cluster Management Server Daemon.
NDBevent was left behind but the corresponding table was later recreated and received a new table ID, the event could not be dropped. (Bug #30877)
When creating an
NDBtable with a column that has
COLUMN_FORMAT = DYNAMIC, but the table itself uses
ROW_FORMAT=FIXED, the table is considered dynamic, but any columns for which the row format is unspecified default to
FIXED. Now in such cases the server issues the warning Row format FIXED incompatible with dynamic attribute
column_name. (Bug #30276)
An insufficiently descriptive and potentially misleading Error 4006 (Connect failure - out of connection objects...) was produced when either of the following two conditions occurred:
There were no more transaction records in the transaction coordinator
NDBobject in the NDB API was initialized with insufficient parallelism
Separate error messages are now generated for each of these two cases. (Bug #11313)
Functionality Added or Changed
Reporting functionality has been significantly enhanced in this release:
A new configuration parameter
BackupReportFrequencynow makes it possible to cause the management client to provide status reports at regular intervals as well as for such reports to be written to the cluster log (depending on cluster event logging levels).
REPORTcommand has been added in the cluster management client.
REPORT BackupStatusenables you to obtain a backup status report at any time during a backup.
REPORT MemoryUsagereports the current data memory and index memory used by each data node. For more about the
REPORTcommand, see Commands in the MySQL Cluster Management Client.
ndb_restore now provides running reports of its progress when restoring a backup. In addition, a complete report status report on the backup is written to the cluster log.