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MySQL NDB Cluster 7.4 Release Notes  /  Release Series Changelogs: MySQL NDB Cluster 7.4  /  Changes in MySQL NDB Cluster 7.4.12 (5.6.31-ndb-7.4.12) (2016-07-18, General Availability)

Changes in MySQL NDB Cluster 7.4.12 (5.6.31-ndb-7.4.12) (2016-07-18, General Availability)

Bugs Fixed

  • Incompatible Change: When the data nodes are only partially connected to the API nodes, a node used for a pushdown join may get its request from a transaction coordinator on a different node, without (yet) being connected to the API node itself. In such cases, the NodeInfo object for the requesting API node contained no valid info about the software version of the API node, which caused the DBSPJ block to assume (incorrectly) when aborting to assume that the API node used NDB version 7.2.4 or earlier, requiring the use of a backward compatability mode to be used during query abort which sent a node failure error instead of the real error causing the abort.

    Now, whenever this situation occurs, it is assumed that, if the NDB software version is not yet available, the API node version is greater than 7.2.4. (Bug #23049170)

  • NDB Cluster APIs: Deletion of Ndb objects used a dispoportionately high amount of CPU. (Bug #22986823)

  • Although arguments to the DUMP command are 32-bit integers, ndb_mgmd used a buffer of only 10 bytes when processing them. (Bug #23708039)

  • During shutdown, the mysqld process could sometimes hang after logging NDB Util: Stop ... NDB Util: Wakeup. (Bug #23343739)

    References: See also: Bug #21098142.

  • During an online upgrade from a MySQL NDB Cluster 7.3 release to an NDB 7.4 (or later) release, the failures of several data nodes running the lower version during local checkpoints (LCPs), and just prior to upgrading these nodes, led to additional node failures following the upgrade. This was due to lingering elements of the EMPTY_LCP protocol initiated by the older nodes as part of an LCP-plus-restart sequence, and which is no longer used in NDB 7.4 and later due to LCP optimizations implemented in those versions. (Bug #23129433)

  • Reserved send buffer for the loopback transporter, introduced in MySQL NDB Cluster 7.4.8 and used by API and management nodes for administrative signals, was calculated incorrectly. (Bug #23093656, Bug #22016081)

    References: This issue is a regression of: Bug #21664515.

  • During a node restart, re-creation of internal triggers used for verifying the referential integrity of foreign keys was not reliable, because it was possible that not all distributed TC and LDM instances agreed on all trigger identities. To fix this problem, an extra step is added to the node restart sequence, during which the trigger identities are determined by querying the current master node. (Bug #23068914)

    References: See also: Bug #23221573.

  • Following the forced shutdown of one of the 2 data nodes in a cluster where NoOfReplicas=2, the other data node shut down as well, due to arbitration failure. (Bug #23006431)

  • The ndbinfo.tc_time_track_stats table uses histogram buckets to give a sense of the distribution of latencies. The sizes of these buckets were also reported as HISTOGRAM BOUNDARY INFO messages during data node startup; this printout was redundant and so has been removed. (Bug #22819868)

  • A failure occurred in DBTUP in debug builds when variable-sized pages for a fragment totalled more than 4 GB. (Bug #21313546)

  • mysqld did not shut down cleanly when executing ndb_index_stat. (Bug #21098142)

    References: See also: Bug #23343739.

  • DBDICT and GETTABINFOREQ queue debugging were enhanced as follows:

    • Monitoring by a data node of the progress of GETTABINFOREQ signals can be enabled by setting DictTrace >= 2.

    • Added the ApiVerbose configuration parameter, which enables NDB API debug logging for an API node where it is set greater than or equal to 2.

    • Added DUMP code 1229 which shows the current state of the GETTABINFOREQ queue. (See DUMP 1229.)

    See also The DBDICT Block. (Bug #20368450)

    References: See also: Bug #20368354.