MySQL NDB Cluster 8.2 is an Innovation release of NDB 8.2, based
on MySQL Server 8.2 and including features in version 8.2 of the
NDB storage engine, as well as fixing
recently discovered bugs in previous NDB Cluster releases.
Obtaining NDB Cluster 8.2. NDB Cluster 8.2 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/.
For an overview of changes made in NDB Cluster 8.2, see What is New in MySQL NDB Cluster 8.2.
This release also incorporates all bug fixes and changes made in previous NDB Cluster releases, as well as all bug fixes and feature changes made in mainline MySQL 8.2 (see Changes in MySQL 8.2.0 (2023-10-25, Innovation Release)).
NDB Replication: Updates to primary keys of character types were not correctly represented in the
AFTERtrigger values sent to the NDB binary log injector. This issue was previously fixed in part, but it was discovered subsequently that the problem still occurred when the mysqld was run with the binary logging options having the values listed here:
The minimal binary log format excluded all primary key columns from the
AFTERvalues reflecting the updated row, the rationale for this being a flawed assumption that the primary key remained constant when an update trigger was received. This did not take into account the fact that, if the primary key uses a character data type, an update trigger is received if character columns are updated to values treated as equal by the comparison rules of the collation used.
To be able to replicate such changes, we need to include them in the
AFTERvalues; this fix ensures that we do so. (Bug #34540016)
References: See also: Bug #27522732, Bug #34312769, Bug #34388068.
NDB Cluster APIs: The header files
mgmapi.hrequired C++ to compile, even though they should require C only. (Bug #35709497)
NDB Cluster APIs:
Ndb::pollEvents2()did not set NDB_FAILURE_GCI (
~(Uint64)0) to indicate cluster failure. (Bug #35671818)
References: See also: Bug #31926584. This issue is a regression of: Bug #18753887.
NDB Client Programs: When ndb_select_all failed to read all data from the table, it always tried to re-read it. This could lead to the two problems listed here:
Returning a non-empty partial result eventually led to spurious reports of duplicate rows.
The table header was printed on every retry.
Now when ndb_select_all is unsuccessful at reading all the table data, its behavior is as follows:
NDB Cluster did not compile using Clang 15. (Bug #35763112)
src/common/transporter/Transporter.cpplacked a matching
DBUG_RETURN. (Bug #35717730)
TransporterRegistry(TR) instance connects to a management server, it first uses the MGM API, and then converts the connection to a
Transporterconnection for further communication. The initial connection had an excessively long timeout (60 seconds) so that, in the case of a cluster having two management servers where one was unavailable, clients were forced to wait until this management server timed out before being able to connect to the available one.
We fix this by setting the MGM API connection timeout to 5000 milliseconds, which is equal to the timeout used by the TR for getting and setting dynamic ports. (Bug #35714466)
Values for causes of conflicts used in conflict resolution exceptions tables were misaligned such that the order of
ROW_DOES_NOT_EXISTwas reversed. (Bug #35708719)
When TLS is used over the TCP transporter, the
ssl_writev()method may return
TLS_BUSY_TRY_AGAINin cases where the underlying
SSL_write()returned either SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE, which is used to indicate to the upper layers that it is necessary to try the write again later.
TCP_Transporter::doSend()may write in a loop in which multiple blocks of buffered data are written using a sequence of
writev()calls, we may have successfully written some buffered data before encountering an SSL_ERROR_WANT_WRITE. In such cases the handling of the
TLS_BUSY_TRY_AGAINwas simply to return from the loop, without first calling
iovec_data_sent(sum_sent)in order to inform the buffering layer of what was sent.
This resulted in later tries to resend a chunk which had already been sent, calling
writev()with both duplicated data and an incorrect length argument. This resulted in a combination of checksum errors and SSL
writev()failing with bad length errors reported in the logs.
We fix this by breaking out of the send loop rather than just returning, so that execution falls through to the point in the code where such status updates are supposed to take place. (Bug #35693207)
Removed a memory leak found in
src/mgmclient/main.cpp. (Bug #35641639)
NDBFSdebugging output for bad requests. (Bug #35500304)
References: This issue is a regression of: Bug #28922609.
When other events led to
NDBFSdumping requests to the log, some of the names of the request types were printed as
Unknown action. (Bug #35499931)
ndb_restore did not update compare-as-equal primary key values changed during backup. (Bug #35420131)
NOWAITdid not start following a restart of the data node. (Bug #35389533)
In cases where the distributed global checkpoint (GCP) protocol stops making progress, this is detected and optionally handled by the GCP monitor, with handling as determined by the
TimeBetweenGlobalCheckpointsTimeoutdata node parameters.
The LCP protocol is mostly node-local, but depends on the progress of the GCP protocol at the end of a local checkpoint (LCP); this means that, if the GCP protocol stalls, LCPs may also stall in this state. If the LCP watchdog detects that the LCP is stalled in this end state, it should defer to the GCP monitor to handle this situation, since the GCP Monitor is distribution-aware.
If no GCP monitor limit is set (
TimeBetweenEpochsTimeoutis equal 0), no handling of GCP stalls is performed by the GCP monitor. In this case, the LCP watchdog was still taking action which could eventually lead to cluster failure; this fix corrects this misbehavior so that the LCP watchdog no longer takes any such action. (Bug #29885899)
Previously, when a timeout was detected during transaction commit and completion, the transaction coordinator (TC) switched to a serial commit-complete execution protocol, which slowed commit-complete processing for large transactions, affecting
GCP_COMMITdelays and epoch sizes. Instead of switching in such cases, the TC now continues waiting for parallel commit-complete, periodically logging a transaction summary, with states and nodes involved. (Bug #22602898)
References: See also: Bug #35260944.