MySQL Cluster 7.4.4 has been released

[Balasubramanian Kandasamy]

Dear MySQL Users,

MySQL Cluster 7.4.4 (GA) is a first GA release for  MySQL Cluster 7.4.

MySQL Cluster is the distributed, shared-nothing variant of MySQL.
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
  - 99.999% 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 7.4 makes significant advances in performance;
operational efficiency (such as enhanced reporting and faster restarts
and upgrades) and conflict detection and resolution for active-active
replication between MySQL Clusters.

MySQL Cluster 7.4.4 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/7.4/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 Cluster NDB 7.4.4 (5.6.23-ndb-7.4.4) (2015-02-26, General Availability)

   MySQL Cluster NDB 7.4.4 is a new release of MySQL Cluster,
   based on MySQL Server 5.6 and including features under
   development for version 7.4 of the NDB storage engine, as
   well as fixing a number of recently discovered bugs in
   previous MySQL Cluster releases.

   Obtaining MySQL Cluster NDB 7.4.  MySQL Cluster NDB 7.4
   source code and binaries can be obtained from
   http://dev.mysql.com/downloads/cluster/.

   For an overview of changes made in MySQL Cluster NDB 7.4, see
   MySQL Cluster Development in MySQL Cluster NDB 7.4
   (http://dev.mysql.com/doc/refman/5.6/en/mysql-cluster-develop
    ment-5-6-ndb-7-4.html).

   This release also incorporates all bugfixes and changes made
   in previous MySQL Cluster releases, as well as all bugfixes
   and feature changes which were added in mainline MySQL 5.6
   through MySQL 5.6.23 (see Changes in MySQL 5.6.23
   (2015-02-02)
   (http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-23.h
   tml)).

   Bugs Fixed

     * The values of the Ndb_last_commit_epoch_server and
       Ndb_last_commit_epoch_session status variables were
       incorrectly reported on some platforms. To correct this
       problem, these values are now stored internally as long
       long, rather than long. (Bug #20372169)

     * When a data node fails or is being restarted, the
       remaining nodes in the same nodegroup resend to
       subscribers any data which they determine has not already
       been sent by the failed node. Normally, when a data node
       (actually, the SUMA kernel block) has sent all data
       belonging to an epoch for which it is responsible, it
       sends a SUB_GCP_COMPLETE_REP signal, together with a
       count, to all subscribers, each of which responds with a
       SUB_GCP_COMPLETE_ACK. When SUMA receives this
       acknowledgment from all subscribers, it rports this to
       the other nodes in the same nodegroup so that they know
       that there is no need to resend this data in case of a
       subsequent node failure. If a node failed before all
       subscribers sent this acknowledgement but before all the
       other nodes in the same nodegroup received it from the
       failing node, data for some epochs could be sent (and
       reported as complete) twice, which could lead to an
       unplanned shutdown.
       The fix for this issue adds to the count reported by
       SUB_GCP_COMPLETE_ACK a list of identifiers which the
       receiver can use to keep track of which buckets are
       completed and to ignoreany duplicate reported for an
       already completed bucket. (Bug #17579998)

     * The output format of SHOW CREATE TABLE for an NDB table
       containing foreign key constraints did not match that for
       the equivalent InnoDB table, which could lead to issues
       with some third-party applications. (Bug #75515, Bug
       #20364309)

     * An ALTER TABLE statement containing comments and a
       partitioning option against an NDB table caused the SQL
       node on which it was executed to fail. (Bug #74022, Bug
       #19667566)

     * Cluster API: When a transaction is started from a cluster
       connection, Table and Index schema objects may be passed
       to this transaction for use. If these schema objects have
       been acquired from a different connection
       (Ndb_cluster_connection object), they can be deleted at
       any point by the deletion or disconnection of the owning
       connection. This can leave a connection with invalid
       schema objects, which causes an NDB API application to
       fail when these are dereferenced.
       To avoid this problem, if your application uses multiple
       connections, you can now set a check to detect sharing of
       schema objects between connections when passing a schema
       object to a transaction, using the
       NdbTransaction::setSchemObjectOwnerChecks() method added
       in this release. When this check is enabled, the schema
       objects having the same names are acquired from the
       connection and compared to the schema objects passed to
       the transaction. Failure to match causes the application
       to fail with an error. (Bug #19785977)

     * Cluster API: The increase in the default number of
       hashmap buckets (DefaultHashMapSize API node
       configuration parameter) from 240 to 3480 in MySQL
       Cluster NDB 7.2.11 increased the size of the internal
       DictHashMapInfo::HashMap type considerably. This type was
       allocated on the stack in some getTable() calls which
       could lead to stack overflow issues for NDB API users.
       To avoid this problem, the hashmap is now dynamically
       allocated from the heap. (Bug #19306793)

On behalf of Oracle/MySQL RE Team