MySQL Cluster 7.5.0 has been released (part 3/3)

[Balasubramanian Kandasamy]

[This is part 3 of the announcement] 

     * Cluster API: The binlog injector did not work correctly
       with TE_INCONSISTENT event type handling by Ndb::nextEvent()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-methods.html#
       ndb-ndb-nextevent). (Bug #22135541) References: See also Bug
       #20646496.

     * Cluster API: While executing dropEvent()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-dictionary-method
       s.html#ndb-dictionary-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()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-dictionary-method
       s.html#ndb-dictionary-dropevent) with a nonzero force argument.
       Now in such cases, error 1419 is ignored, and DBDICT deletes the
       event from the table. (Bug #21554676)

     * Cluster API: Ndb::pollEvents()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-methods.html#
       ndb-ndb-pollevents) and pollEvents2()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-methods.html#
       ndb-ndb-pollevents2) were slow to receive events, being dependent
       on other client threads or blocks to perform polling of
       transporters on their behalf. This fix allows a client thread to
       perform its own transporter polling when it has to wait in either
       of these methods.  Introduction of transporter polling also
       revealed a problem with missing mutex protection in the
       ndbcluster_binlog handler, which has been added as part of this
       fix. (Bug #20957068, Bug #22224571, Bug #79311)

     * Cluster API: The pollEvents2()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-methods.html#
       ndb-ndb-pollevents2) method now waits indefinitely for events
       when a negative value is used for the time argument. (Bug
       #20762291)

     * Cluster API: Creation and destruction of
       Ndb_cluster_connection
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-cluster-conne
       ction.html) objects by multiple threads could make use of the
       same application lock, which in some cases led to failures in the
       global dictionary cache. To alleviate this problem, the creation
       and destruction of several internal NDB API objects have been
       serialized. (Bug #20636124)

     * Cluster API: When an Ndb
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html) object created
       prior to a failure of the cluster was reused, the event queue of
       this object could still contain data node events originating from
       before the failure. These events could reference "old" epochs
       (from before the failure occurred), which in turn could violate
       the assumption made by the nextEvent()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-methods.html#
       ndb-ndb-nextevent) method that epoch numbers always increase.
       This issue is addressed by explicitly clearing the event queue in
       such cases. (Bug #18411034) References: See also Bug #20888668.

     * Cluster API: After the initial restart of a node
       following a cluster failure, the cluster failure event added as
       part of the restart process was deleted when an event that
       existed prior to the restart was later deleted. This meant that,
       in such cases, an Event API client had no way of knowing that
       failure handling was needed. In addition, the GCI used for the
       final cleanup of deleted event operations, performed by
       pollEvents()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-methods.html#
       ndb-ndb-pollevents) and nextEvent()
       (http://dev.mysql.com/doc/ndbapi/en/ndb-ndb-methods.html#
       ndb-ndb-nextevent) when these methods have consumed all available
       events, was lost. (Bug #78143, Bug #21660947)

On behalf of the MySQL Release Team,
Balasubramanian Kandasamy