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MySQL Cluster 8.0.14-dmr has been released
Posted by: Piotr Obrzut
Date: January 21, 2019 03:49AM

Dear MySQL Users,

MySQL Cluster is the distributed database combining massive
scalability and high availability. It provides in-memory
real-time access with transactional consistency across
partitioned and distributed datasets. It is designed for
mission critical applications.

MySQL Cluster has replication between clusters across multiple
geographical sites built-in. A shared nothing architecture with
data locality awareness make it the perfect choice for running
on commodity hardware and in globally distributed cloud
infrastructure.


This storage engine provides:

  - In-Memory storage - Real-time performance (with optional
    checkpointing to disk)
  - Transparent Auto-Sharding - Read & write scalability
  - Active-Active/Multi-Master geographic replication
  - Transactional consistency across partitioned and distributed datasets
  - Parallel cross partition queries such as joins

  - 99.9999% High Availability with no single point of failure
    and on-line maintenance
  - NoSQL and SQL APIs (including C++, Java, http, Memcached
    and JavaScript/Node.js)

MySQL Cluster 8.0.13-dmr, has been released and can be downloaded from

  http://www.mysql.com/downloads/cluster/

where you will also find Quick Start guides to help you get your
first MySQL Cluster database up and running.

The release notes are available from

  http://dev.mysql.com/doc/relnotes/mysql-cluster/8.0/en/index.html

MySQL Cluster enables users to meet the database challenges of next
generation web, cloud, and communications services with uncompromising
scalability, uptime and agility.

More details can be found at

  http://www.mysql.com/products/cluster/

Enjoy !

Changes in MySQL NDB Cluster 8.0.14 (2019-01-21, Development Milestone)

   MySQL NDB Cluster 8.0.14 is a new development release of NDB
   8.0, based on MySQL Server 8.0 and including features in
   version 8.0 of the NDB storage engine, as well as fixing
   recently discovered bugs in previous NDB Cluster releases.

   Obtaining NDB Cluster 8.0.  NDB Cluster 8.0 source code and
   binaries can be obtained from
   https://dev.mysql.com/downloads/cluster/.

   For an overview of changes made in NDB Cluster 8.0, see What
   is New in NDB Cluster
(http://dev.mysql.com/doc/refman/8.0/en/mysql-cluster-what-is-new.html).

   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 8.0
   through MySQL 8.0.14 (see Changes in MySQL 8.0.14 (Not yet
   released, General Availability)
(http://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-14.html)).

     * Functionality Added or Changed

     * Bugs Fixed

Functionality Added or Changed


     * Performance: This release introduces a number of
       significant improvements in the performance of scans;
       these are listed here:

          + Row checksums help detect hardware issues, but do so
            at the expense of performance. NDB now offers the
            possibility of disabling these by setting the new
            ndb_row_checksum server system variable to 0; doing
            this means that row checksums are not used for new
            or altered tables. This can have a significant
            impact (5 to 10 percent, in some cases) on
            performance for all types of queries. This variable
            is set to 1 by default, to provide compatibility
            with the previous behavior.

          + A query consisting of a scan can execute for a
            longer time in the LDM threads when the queue is not
            busy.

          + Previously, columns were read before checking a
            pushed condition; now checking of a pushed condition
            is done before reading any columns.

          + Performance of pushed joins should see significant
            improvement when using range scans as part of join
            execution.

     * NDB Disk Data: MySQL NDB Cluster now implements schema
       synchronization of disk data objects including
       tablespaces and log file groups, just as it does for NDB
       databases and in-memory tables. This eliminates a
       possible mismatch between the MySQL data dictionary and
       the NDB dictionary following a native backup and restore
       that could arise when disk data tablespaces and undo log
       file groups were restored to the NDB dictionary, but not
       to the MySQL Server's data dictionary.

     * NDB Disk Data: NDB now makes use of the MySQL data
       dictionary to ensure correct distribution of tablespaces
       and log file groups across all cluster SQL nodes.

     * The extra metadata property for NDB tables is now used to
       store information from the MySQL data dictionary. Because
       this information is significantly larger than the binary
       representation previously stored here (a .frm file, no
       longer used), the hard-coded size limit for this extra
       metadata has been increased.
       This change can have an impact on downgrades: Trying to
       read NDB tables created in NDB 8.0.14 and later may cause
       data nodes running NDB 8.0.13 or earlier to fail on
       startup with NDB error code 2355 Failure to restore
       schema: Permanent error, external action needed: Resource
       configuration error. This can happen if the table's
       metadata exceeds 6K in size, which was the old limit.
       Tables created in NDB 8.0.13 and earlier can be read by
       later versions without any issues.
       For more information, see NDB table extra metadata
       changes
(http://dev.mysql.com/doc/refman/8.0/en/mysql-cluster-what-is-new.html#mysql-cluster-what-is-new-8-0-extra-metadata),
       and See also MySQL Data Dictionary
(http://dev.mysql.com/doc/refman/8.0/en/data-dictionary.html).

Bugs Fixed

     * Packaging: Expected NDB header files were in the devel
       RPM package instead of libndbclient-devel. (Bug #84580,
       Bug #26448330)

     * MySQL NDB ClusterJ: The ndb.clusterj test for NDB 8.0.13
       failed when being run more than once. This was deal to a
       new, stricter rule with NDB 8.0.13 that did not allow
       temporary files being left behind in the variable folder
       of mysql-test-run (mtr). With this fix, the temporary
       files are deleted before the test is executed. (Bug
       #28279038)

     * MySQL NDB ClusterJ: A NullPointerException was thrown
       when a full table scan was performed with ClusterJ on
       tables containing either a BLOB or a TEXT field. It was
       because the proper object initializations were omitted,
       and they have now been added by this fix. (Bug #28199372,
       Bug #91242)

     * Trying to build from source using -DWITH_NDBCLUSTER and
       -Werror failed with GCC 8. (Bug #28707282)

     * When copying deleted rows from a live node to a node just
       starting, it is possible for one or more of these rows to
       have a global checkpoint index equal to zero. If this
       happened at the same time that a full local checkpoint
       was started due to the undo log getting full, the
       LCP_SKIP bit was set for a row having GCI = 0, leading to
       an unplanned shutdown of the data node. (Bug #28372628)

     * ndbmtd sometimes experienced a hang when exiting due to
       log thread shutdown. (Bug #28027150)

     * NDB has an upper limit of 128 characters for a fully
       qualified table name. Due to the fact that mysqld names
       NDB tables using the format
       database_name/catalog_name/table_name, where catalog_name
       is always def, it is possible for statements such as
       CREATE TABLE to fail in spite of the fact that neither
       the table name nor the database name exceeds the
       63-character limit imposed by NDB. The error raised in
       such cases was misleading and has been replaced. (Bug
       #27769521)
       References: See also: Bug #27769801.

     * When the SUMA kernel block receives a SUB_STOP_REQ
       signal, it executes the signal then replies with
       SUB_STOP_CONF. (After this response is relayed back to
       the API, the API is open to send more SUB_STOP_REQ
       signals.) After sending the SUB_STOP_CONF, SUMA drops the
       subscription if no subscribers are present, which
       involves sending multiple DROP_TRIG_IMPL_REQ messages to
       DBTUP. LocalProxy can handle up to 21 of these requests
       in parallel; any more than this are queued in the Short
       Time Queue. When execution of a DROP_TRIG_IMPL_REQ was
       delayed, there was a chance for the queue to become
       overloaded, leading to a data node shutdown with Error in
       short time queue.
       This issue is fixed by delaying the execution of the
       SUB_STOP_REQ signal if DBTUP is already handling
       DROP_TRIG_IMPL_REQ signals at full capacity, rather than
       queueing up the DROP_TRIG_IMPL_REQ signals. (Bug
       #26574003)

     * When starting, a data node copies metadata, while a local
       checkpoint updates metadata. To avoid any conflict, any
       ongoing LCP activity is paused while metadata is being
       copied. An issue arose when a local checkpoint was paused
       on a given node, and another node that was also
       restarting checked for a complete LCP on this node; the
       check actually caused the LCP to be completed before
       copying of metadata was complete and so ended the pause
       prematurely. Now in such cases, the LCP completion check
       waits to complete a paused LCP until copying of metadata
       is finished and the pause ends as expected, within the
       LCP in which it began. (Bug #24827685)

     * ndbout and ndberr became invalid after exiting from
       mgmd_run(), and redirecting to them before the next call
       to mgmd_run() caused a segmentation fault, during an
       ndb_mgmd service restart. This fix ensures that ndbout
       and ndberr remain valid at all times. (Bug #17732772, Bug
       #28536919)

     * NdbScanFilter did not always handle NULL according to the
       SQL standard, which could result in sending
       non-qualifying rows to be filtered (otherwise not
       necessary) by the MySQL server. (Bug #92407, Bug
       #28643463)

     * The internal function ndb_my_error() was used in
       ndbcluster_get_tablespace_statistics() and
       prepare_inplace_alter_table() to report errors when the
       function failed to interact with NDB. The function was
       expected to push the NDB error as warning on the stack
       and then set an error by translating the NDB error to a
       MySQL error and then finally call my_error() with the
       translated error. When calling my_error(), the function
       extracts a format string that may contain placeholders
       and use the format string in a function similar to
       sprintf(), which in this case could read arbitrary memory
       leading to a segmentation fault, due to the fact that
       my_error() was called without any arguments.
       The fix is always to push the NDB error as a warning and
       then set an error with a provided message. A new helper
       function has been added to Thd_ndb to be used in place of
       ndb_my_error(). (Bug #92244, Bug #28575934)

     * Running out of undo log buffer memory was reported using
       error 921 Out of transaction memory ... (increase
       SharedGlobalMemory).
       This problem is fixed by introducing a new error code 923
       Out of undo buffer memory (increase UNDO_BUFFER_SIZE).
       (Bug #92125, Bug #28537319)

     * When moving an OperationRec from the serial to the
       parallel queue, Dbacc::startNext() failed to update the
       Operationrec::OP_ACC_LOCK_MODE flag which is required to
       reflect the accumulated OP_LOCK_MODE of all previous
       operations in the parallel queue. This inconsistency in
       the ACC lock queues caused the scan lock takeover
       mechanism to fail, as it incorrectly concluded that a
       lock to take over was not held. The same failure caused
       an assert when aborting an operation that was a member of
       such an inconsistent parallel lock queue. (Bug #92100,
       Bug #28530928)

     * ndb_restore did not free all memory used after being
       called to restore a table that already existed. (Bug
       #92085, Bug #28525898)

     * A data node failed during startup due to the arrival of a
       SCAN_FRAGREQ signal during the restore phase. This signal
       originated from a scan begun before the node had
       previously failed and which should have been aborted due
       to the involvement of the failed node in it. (Bug #92059,
       Bug #28518448)

     * DBTUP sent the error Tuple corruption detected when a
       read operation attempted to read the value of a tuple
       inserted within the same transaction. (Bug #92009, Bug
       #28500861)

     * False constraint violation errors could occur when
       executing updates on self-referential foreign keys. (Bug
       #91965, Bug #28486390)
       References: See also: Bug #90644, Bug #27930382.

     * An NDB internal trigger definition could be dropped while
       pending instances of the trigger remained to be executed,
       by attempting to look up the definition for a trigger
       which had already been released. This caused
       unpredictable and thus unsafe behavior possibly leading
       to data node failure. The root cause of the issue lay in
       an invalid assumption in the code relating to determining
       whether a given trigger had been released; the issue is
       fixed by ensuring that the behavior of NDB, when a
       trigger definition is determined to have been released,
       is consistent, and that it meets expectations. (Bug
       #91894, Bug #28451957)

     * During an initial node restart with disk data tables
       present and TwoPassInitialNodeRestartCopy enabled, DBTUP
       used an unsafe scan in disk order. Such scans are no
       longer employed in this case. (Bug #91724, Bug #28378227)

     * Checking for old LCP files tested the table version, but
       this was not always dependable. Now, instead of relying
       on the table version, the check regards as invalid any
       LCP file having a maxGCI smaller than its createGci. (Bug
       #91637, Bug #28346565)

     * In certain cases, a cascade update trigger was fired
       repeatedly on the same record, which eventually consumed
       all available concurrent operations, leading to Error 233
       Out of operation records in transaction coordinator
       (increase MaxNoOfConcurrentOperations). If
       MaxNoOfConcurrentOperations was set to a value
       sufficiently high to avoid this, the issue manifested as
       data nodes consuming very large amounts of CPU, very
       likely eventually leading to a timeout. (Bug #91472, Bug
       #28262259)


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