-
NDB Cluster APIs: Added as an aid to debugging the ability to specify a human-readable name for a given
Ndb
object and later to retrieve it. These operations are implemented, respectively, as thesetNdbObjectName()
andgetNdbObjectName()
methods.To make tracing of event handling between a user application and
NDB
easier, you can use the reference (fromgetReference()
followed by the name (if provided) in printouts; the reference ties together the applicationNdb
object, the event buffer, and theNDB
storage engine'sSUMA
block. (Bug #18419907)
NDB Disk Data: Setting the undo buffer size used by
InitialLogFileGroup
to a value greater than that set bySharedGlobalMemory
prevented data nodes from starting; the data nodes failed with Error 1504 Out of logbuffer memory. While the failure itself is expected behavior, the error message did not provide sufficient information to diagnose the actual source of the problem; now in such cases, a more specific error message Out of logbuffer memory (specify smaller undo_buffer_size or increase SharedGlobalMemory) is supplied. (Bug #11762867, Bug #55515)NDB Cluster APIs: When two tables had different foreign keys with the same name, ndb_restore considered this a name conflict and failed to restore the schema. As a result of this fix, a slash character (
/
) is now expressly disallowed in foreign key names, and the naming formatparent_id
/child_id
/fk_name
is now enforced by the NDB API. (Bug #18824753)-
NDB Cluster APIs: When an
NDB
data node indicates a buffer overflow via an empty epoch, the event buffer places an inconsistent data event in the event queue. When this was consumed, it was not removed from the event queue as expected, causing subsequentnextEvent()
calls to return 0. This caused event consumption to stall because the inconsistency remained flagged forever, while event data accumulated in the queue.Event data belonging to an empty inconsistent epoch can be found either at the beginning or somewhere in the middle.
pollEvents()
returns 0 for the first case. This fix handles the second case: callingnextEvent()
call dequeues the inconsistent event before it returns. In order to benefit from this fix, user applications must callnextEvent()
even whenpollEvents()
returns 0. (Bug #18716991) NDB Cluster APIs: The
pollEvents()
method returned 1, even when called with a wait time equal to 0, and there were no events waiting in the queue. Now in such cases it returns 0 as expected. (Bug #18703871)-
Processing a NODE_FAILREP signal that contained an invalid node ID could cause a data node to fail. (Bug #18993037, Bug #73015)
References: This issue is a regression of: Bug #16007980.
When building out of source, some files were written to the source directory instead of the build dir. These included the
manifest.mf
files used for creating ClusterJ jars and thepom.xml
file used bymvn_install_ndbjtie.sh
. In addition,ndbinfo.sql
was written to the build directory, but marked as output to the source directory inCMakeLists.txt
. (Bug #18889568, Bug #72843)When the binary log injector thread commits an epoch to the binary log and this causes the log file to reach maximum size, it may need to rotate the binary log. The rotation is not performed until either all the committed transactions from all client threads are flushed to the binary log, or a maximum of 30 seconds has elapsed. In the case where all transactions were committed prior to the 30-second wait, it was possible for committed transactions from multiple client threads to belong to newer epochs than the latest epoch committed by the injector thread, causing the thread to deadlock with itself, and causing an unnecessary 30-second delay before breaking the deadlock. (Bug #18845822)
Adding a foreign key failed with NDB Error 208 if the parent index was parent table's primary key, the primary key was not on the table's initial attributes, and the child table was not empty. (Bug #18825966)
-
When an
NDB
table served as both the parent table and a child table for 2 different foreign keys having the same name, dropping the foreign key on the child table could cause the foreign key on the parent table to be dropped instead, leading to a situation in which it was impossible to drop the remaining foreign key. This situation can be modelled using the followingCREATE TABLE
statements:CREATE TABLE parent ( id INT NOT NULL, PRIMARY KEY (id) ) ENGINE=NDB; CREATE TABLE child ( id INT NOT NULL, parent_id INT, PRIMARY KEY (id), INDEX par_ind (parent_id), FOREIGN KEY (parent_id) REFERENCES parent(id) ) ENGINE=NDB; CREATE TABLE grandchild ( id INT, parent_id INT, INDEX par_ind (parent_id), FOREIGN KEY (parent_id) REFERENCES child(id) ) ENGINE=NDB;
With the tables created as just shown, the issue occurred when executing the statement
ALTER TABLE child DROP FOREIGN KEY parent_id
, because it was possible in some cases forNDB
to drop the foreign key from thegrandchild
table instead. When this happened, any subsequent attempt to drop the foreign key from either thechild
or from thegrandchild
table failed. (Bug #18662582) -
It was possible for a data node restart to become stuck indefinitely in start phase 101 (see Summary of NDB Cluster Start Phases) when there were connection problems between the node being restarted and one or more subscribing API nodes.
To help prevent this from happening, a new data node configuration parameter
RestartSubscriberConnectTimeout
has been introduced, which can be used to control how long a data node restart can stall in start phase 101 before giving up and attempting to restart again. The default is 12000 ms. (Bug #18599198) -
Executing
ALTER TABLE ... REORGANIZE PARTITION
after increasing the number of data nodes in the cluster from 4 to 16 led to a crash of the data nodes. This issue was shown to be a regression caused by previous fix which added a new dump handler using a dump code that was already in use (7019), which caused the command to execute two different handlers with different semantics. The new handler was assigned a newDUMP
code (7024). (Bug #18550318)References: This issue is a regression of: Bug #14220269.
Following a long series of inserts, when running with a relatively small redo log and an insufficient large value for
MaxNoOfConcurrentTransactions
, there remained transactions that were blocked by the lack of redo log and were thus not aborted in the correct state (waiting for prepare log to be sent to disk, orLOG_QUEUED
state). This caused the redo log to remain blocked until unblocked by a completion of a local checkpoint. This could lead to a deadlock, when the blocked aborts in turned blocked global checkpoints, and blocked GCPs block LCPs. To prevent this situation from arising, we now abort immediately when we reach theLOG_QUEUED
state in the abort state handler. (Bug #18533982)-
ndbmtd supports multiple parallel receiver threads, each of which performs signal reception for a subset of the remote node connections (transporters) with the mapping of remote_nodes to receiver threads decided at node startup. Connection control is managed by the multi-instance
TRPMAN
block, which is organized as a proxy and workers, and each receiver thread has aTRPMAN
worker running locally.The
QMGR
block sends signals toTRPMAN
to enable and disable communications with remote nodes. These signals are sent to theTRPMAN
proxy, which forwards them to the workers. The workers themselves decide whether to act on signals, based on the set of remote nodes they manage.The current issue arises because the mechanism used by the
TRPMAN
workers for determining which connections they are responsible for was implemented in such a way that each worker thought it was responsible for all connections. This resulted in theTRPMAN
actions forOPEN_COMORD
,ENABLE_COMREQ
, andCLOSE_COMREQ
being processed multiple times.The fix keeps
TRPMAN
instances (receiver threads) executingOPEN_COMORD
,ENABLE_COMREQ
andCLOSE_COMREQ
requests. In addition, the correctTRPMAN
instance is now chosen when routing from this instance for a specific remote connection. (Bug #18518037) -
During data node failure handling, the transaction coordinator performing takeover gathers all known state information for any failed TC instance transactions, determines whether each transaction has been committed or aborted, and informs any involved API nodes so that they can report this accurately to their clients. The TC instance provides this information by sending
TCKEY_FAILREF
orTCKEY_FAILCONF
signals to the API nodes as appropriate top each affected transaction.In the event that this TC instance does not have a direct connection to the API node, it attempts to deliver the signal by routing it through another data node in the same node group as the failing TC, and sends a
GSN_TCKEY_FAILREFCONF_R
signal to TC block instance 0 in that data node. A problem arose in the case of multiple transaction cooridnators, when this TC instance did not have a signal handler for such signals, which led it to fail.This issue has been corrected by adding a handler to the TC proxy block which in such cases forwards the signal to one of the local TC worker instances, which in turn attempts to forward the signal on to the API node. (Bug #18455971)
When running with a very slow main thread, and one or more transaction coordinator threads, on different CPUs, it was possible to encounter a timeout when sending a
DIH_SCAN_GET_NODESREQ
signal, which could lead to a crash of the data node. Now in such cases the timeout is avoided. (Bug #18449222)Failure of multiple nodes while using ndbmtd with multiple TC threads was not handled gracefully under a moderate amount of traffic, which could in some cases lead to an unplanned shutdown of the cluster. (Bug #18069334)
-
A local checkpoint (LCP) is tracked using a global LCP state (
c_lcpState
), and eachNDB
table has a status indicator which indicates the LCP status of that table (tabLcpStatus
). If the global LCP state isLCP_STATUS_IDLE
, then all the tables should have an LCP status ofTLS_COMPLETED
.When an LCP starts, the global LCP status is
LCP_INIT_TABLES
and the thread starts setting all theNDB
tables toTLS_ACTIVE
. If any tables are not ready for LCP, the LCP initialization procedure continues withCONTINUEB
signals until all tables have become available and been markedTLS_ACTIVE
. When this initialization is complete, the global LCP status is set toLCP_STATUS_ACTIVE
.This bug occurred when the following conditions were met:
An LCP was in the
LCP_INIT_TABLES
state, and some but not all tables had been set toTLS_ACTIVE
.The master node failed before the global LCP state changed to
LCP_STATUS_ACTIVE
; that is, before the LCP could finish processing all tables.The
NODE_FAILREP
signal resulting from the node failure was processed before the finalCONTINUEB
signal from the LCP initialization process, so that the node failure was processed while the LCP remained in theLCP_INIT_TABLES
state.
Following master node failure and selection of a new one, the new master queries the remaining nodes with a
MASTER_LCPREQ
signal to determine the state of the LCP. At this point, since the LCP status wasLCP_INIT_TABLES
, the LCP status was reset toLCP_STATUS_IDLE
. However, the LCP status of the tables was not modified, so there remained tables withTLS_ACTIVE
. Afterwards, the failed node is removed from the LCP. If the LCP status of a given table isTLS_ACTIVE
, there is a check that the global LCP status is notLCP_STATUS_IDLE
; this check failed and caused the data node to fail.Now the
MASTER_LCPREQ
handler ensures that thetabLcpStatus
for all tables is updated toTLS_COMPLETED
when the global LCP status is changed toLCP_STATUS_IDLE
. (Bug #18044717) -
When performing a copying
ALTER TABLE
operation, mysqld creates a new copy of the table to be altered. This intermediate table, which is given a name bearing the prefix#sql-
, has an updated schema but contains no data. mysqld then copies the data from the original table to this intermediate table, drops the original table, and finally renames the intermediate table with the name of the original table.mysqld regards such a table as a temporary table and does not include it in the output from
SHOW TABLES
; mysqldump also ignores an intermediate table. However,NDB
sees no difference between such an intermediate table and any other table. This difference in how intermediate tables are viewed by mysqld (and MySQL client programs) and by theNDB
storage engine can give rise to problems when performing a backup and restore if an intermediate table existed inNDB
, possibly left over from a failedALTER TABLE
that used copying. If a schema backup is performed using mysqldump and the mysql client, this table is not included. However, in the case where a data backup was done using the ndb_mgm client'sBACKUP
command, the intermediate table was included, and was also included by ndb_restore, which then failed due to attempting to load data into a table which was not defined in the backed up schema.To prevent such failures from occurring, ndb_restore now by default ignores intermediate tables created during
ALTER TABLE
operations (that is, tables whose names begin with the prefix#sql-
). A new option--exclude-intermediate-sql-tables
is added that makes it possible to override the new behavior. The option's default value isTRUE
; to cause ndb_restore to revert to the old behavior and to attempt to restore intermediate tables, set this option toFALSE
. (Bug #17882305) The logging of insert failures has been improved. This is intended to help diagnose occasional issues seen when writing to the
mysql.ndb_binlog_index
table. (Bug #17461625)The
DEFINER
column in theINFORMATION_SCHEMA.VIEWS
table contained erroneous values for views contained in thendbinfo
information database. This could be seen in the result of a query such asSELECT TABLE_NAME, DEFINER FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_SCHEMA='ndbinfo'
. (Bug #17018500)Employing a
CHAR
column that used theUTF8
character set as a table's primary key column led to node failure when restarting data nodes. Attempting to restore a table with such a primary key also caused ndb_restore to fail. (Bug #16895311, Bug #68893)-
The
--order
(-o
) option for the ndb_select_all utility worked only when specified as the last option, and did not work with an equals sign.As part of this fix, the program's
--help
output was also aligned with the--order
option's correct behavior. (Bug #64426, Bug #16374870)