MySQL Cluster 8.0.14-dmr has been released

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)

On Behalf of Oracle/MySQL Release Engineering Team,
Piotr Obrzut



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