Dear MySQL Users,
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 7.3.8 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/7.3/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 7.3.8 (5.6.22-ndb-7.3.8) (2015-01-21)
MySQL Cluster NDB 7.3.8 is a new release of MySQL Cluster,
based on MySQL Server 5.6 and including features from version
7.3 of the NDB storage engine, as well as fixing a number of
recently discovered bugs in previous MySQL Cluster releases.
Obtaining MySQL Cluster NDB 7.3. MySQL Cluster NDB 7.3
source code and binaries can be obtained from
http://dev.mysql.com/downloads/cluster/.
For an overview of changes made in MySQL Cluster NDB 7.3, see
MySQL Cluster Development in MySQL Cluster NDB 7.3
(
http://dev.mysql.com/doc/refman/5.6/en/mysql-cluster-development-5-6-ndb-7-3.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 5.6.22 (see Changes in MySQL 5.6.22
(2014-12-01)
( http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-22.html )).
Functionality Added or Changed
* Performance: Recent improvements made to the
multithreaded scheduler were intended to optimize the
cache behavior of its internal data structures, with
members of these structures placed such that those local
to a given thread do not overflow into a cache line which
can be accessed by another thread. Where required, extra
padding bytes are inserted to isolate cache lines owned
(or shared) by other threads, thus avoiding invalidation
of the entire cache line if another thread writes into a
cache line not entirely owned by itself. This
optimization improved MT Scheduler performance by several
percent.
It has since been found that the optimization just
described depends on the global instance of struct
thr_repository starting at a cache line aligned base
address as well as the compiler not rearranging or adding
extra padding to the scheduler struct; it was also found
that these prerequisites were not guaranteed (or even
checked). Thus this cache line optimization has
previously worked only when g_thr_repository (that is,
the global instance) ended up being cache line aligned
only by accident. In addition, on 64-bit platforms, the
compiler added extra padding words in struct
thr_safe_pool such that attempts to pad it to a cache
line aligned size failed.
The current fix ensures that g_thr_repository is
constructed on a cache line aligned address, and the
constructors modified so as to verify cacheline aligned
adresses where these are assumed by design.
Results from internal testing show improvements in MT
Scheduler read performance of up to 10% in some cases,
following these changes. (Bug #18352514)
* Cluster API: Two new example programs, demonstrating
reads and writes of CHAR, VARCHAR, and VARBINARY column
values, have been added to storage/ndb/ndbapi-examples in
the MySQL Cluster source tree. For more information about
these programs, including source code listings, see NDB
API Simple Array Example
( http://dev.mysql.com/doc/ndbapi/en/ndbapi-examples-array-simple.html )
, and NDB API Simple Array Example Using Adapter
( http://dev.mysql.com/doc/ndbapi/en/ndbapi-examples-array-adapter.html ).
Bugs Fixed
* The global checkpoint commit and save protocols can be
delayed by various causes, including slow disk I/O. The
DIH master node monitors the progress of both of these
protocols, and can enforce a maximum lag time during
which the protocols are stalled by killing the node
responsible for the lag when it reaches this maximum.