MySQL Cluster 7.4.5 has been released
Posted by: Balasubramanian Kandasamy
Date: March 20, 2015 12:52PM
Date: March 20, 2015 12:52PM
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 7.4 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 7.4.5 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 7.4.5 (5.6.23-ndb-7.4.5) (2015-03-20) MySQL Cluster NDB 7.4.5 is a new release of MySQL Cluster 7.4, based on MySQL Server 5.6 and including new features in version 7.4 of the NDB storage engine, as well as fixing 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.html)). Bugs Fixed * When reading and copying transporter short signal data, it was possible for the data to be copied back to the same signal with overlapping memory. (Bug #75930, Bug #20553247) * NDB node takeover code made the assumption that there would be only one takeover record when starting a takeover, based on the further assumption that the master node could never perform copying of fragments. However, this is not the case in a system restart, where a master node can have stale data and so need to perform such copying to bring itself up to date. (Bug #75919, Bug #20546899) * Cluster API: A scan operation, whether it is a single table scan or a query scan used by a pushed join, stores the result set in a buffer. This maximum size of this buffer is calculated and preallocated before the scan operation is started. This buffer may consume a considerable amount of memory; in some cases we observed a 2 GB buffer footprint in tests that executed 100 parallel scans with 2 single-threaded (ndbd) data nodes. This memory consumption was found to scale linearly with additional fragments. A number of root causes, listed here, were discovered that led to this problem: + Result rows were unpacked to full NdbRecord format before they were stored in the buffer. If only some but not all columns of a table were selected, the buffer contained empty space (essentially wasted). + Due to the buffer format being unpacked, VARCHAR and VARBINARY columns always had to be allocated for the maximum size defined for such columns. + BatchByteSize and MaxScanBatchSize values were not taken into consideration as a limiting factor when calculating the maximum buffer size. These issues became more evident in NDB 7.2 and later MySQL Cluster release series. This was due to the fact buffer size is scaled by BatchSize, and that the default value for this parameter was increased fourfold (from 64 to 256) beginning with MySQL Cluster NDB 7.2.1. This fix causes result rows to be buffered using the packed format instead of the unpacked format; a buffered scan result row is now not unpacked until it becomes the current row. In addition, BatchByteSize and MaxScanBatchSize are now used as limiting factors when calculating the required buffer size. Also as part of this fix, refactoring has been done to separate handling of buffered (packed) from handling of unbuffered result sets, and to remove code that had been unused since NDB 7.0 or earlier. The NdbRecord class declaration has also been cleaned up by removing a number of unused or redundant member variables. (Bug #73781, Bug #75599, Bug #19631350, Bug #20408733) On behalf of Oracle/MySQL RE Team Balasubramanian Kandasamy
Subject
Views
Written By
Posted
Sorry, you can't reply to this topic. It has been closed.
Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.