MySQL NDB Cluster 7.2 Release Notes

17 Changes in MySQL NDB Cluster 7.2.22 (5.5.46-ndb-7.2.22) (2015-10-19, General Availability)

MySQL NDB Cluster 7.2.22 is a new release of NDB Cluster, incorporating new features in the NDB storage engine, and fixing recently discovered bugs in previous MySQL NDB Cluster 7.2 development releases.

Obtaining MySQL NDB Cluster 7.2.  MySQL NDB Cluster 7.2 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/.

This release also incorporates all bug fixes and changes made in previous NDB Cluster releases, as well as all bug fixes and feature changes which were added in mainline MySQL 5.5 through MySQL 5.5.46 (see Changes in MySQL 5.5.46 (2015-09-30, General Availability)).

Bugs Fixed

  • NDB Cluster APIs: While executing dropEvent(), if the coordinator DBDICT failed after the subscription manager (SUMA block) had removed all subscriptions but before the coordinator had deleted the event from the system table, the dropped event remained in the table, causing any subsequent drop or create event with the same name to fail with NDB error 1419 Subscription already dropped or error 746 Event name already exists. This occurred even when calling dropEvent() with a nonzero force argument.

    Now in such cases, error 1419 is ignored, and DBDICT deletes the event from the table. (Bug #21554676)

  • NDB Cluster APIs: The internal value representing the latest global checkpoint was not always updated when a completed epoch of event buffers was inserted into the event queue. This caused subsequent calls to Ndb::pollEvents() and pollEvents2() to fail when trying to obtain the correct GCI for the events available in the event buffers. This could also result in later calls to nextEvent() or nextEvent2() seeing events that had not yet been discovered. (Bug #78129, Bug #21651536)

  • Backup block states were reported incorrectly during backups. (Bug #21360188)

    References: See also: Bug #20204854, Bug #21372136.

  • When a data node is known to have been alive by other nodes in the cluster at a given global checkpoint, but its sysfile reports a lower GCI, the higher GCI is used to determine which global checkpoint the data node can recreate. This caused problems when the data node being started had a clean file system (GCI = 0), or when it was more than more global checkpoint behind the other nodes.

    Now in such cases a higher GCI known by other nodes is used only when it is at most one GCI ahead. (Bug #19633824)

    References: See also: Bug #20334650, Bug #21899993. This issue is a regression of: Bug #29167.

  • After restoring the database schema from backup using ndb_restore, auto-discovery of restored tables in transactions having multiple statements did not work correctly, resulting in Deadlock found when trying to get lock; try restarting transaction errors.

    This issue was encountered both in the mysql client, as well as when such transactions were executed by application programs using Connector/J and possibly other MySQL APIs.

    Prior to upgrading, this issue can be worked around by executing SELECT TABLE_NAME, TABLE_SCHEMA FROM INFORMATION_SCHEMA.TABLES WHERE ENGINE = 'NDBCLUSTER' on all SQL nodes following the restore operation, before executing any other statements. (Bug #18075170)

  • ndb_desc used with the --extra-partition-info and --blob-info options failed when run against a table containing one or more TINYBLOB. columns. (Bug #14695968)

  • When attempting to enable index statistics, creation of the required system tables, events and event subscriptions often fails when multiple mysqld processes using index statistics are started concurrently in conjunction with starting, restarting, or stopping the cluster, or with node failure handling. This is normally recoverable, since the affected mysqld process or processes can (and do) retry these operations shortly thereafter. For this reason, such failures are no longer logged as warnings, but merely as informational events. (Bug #77760, Bug #21462846)