MySQL Community Server 5.5.39 has been released
Posted by: Surya Narayana Murthy Narkedimilli
Date: August 01, 2014 01:43AM
Date: August 01, 2014 01:43AM
Dear MySQL users, MySQL Server 5.5.39 is a new version of the 5.5 production release of the world's most popular open source database. MySQL 5.5.39 is recommended for use on production systems. MySQL 5.5 includes several high-impact enhancements to improve the performance and scalability of the MySQL Database, taking advantage of the latest multi-CPU and multi-core hardware and operating systems. In addition, with release 5.5, InnoDB is now the default storage engine for the MySQL Database, delivering ACID transactions, referential integrity and crash recovery by default. MySQL 5.5 also provides a number of additional enhancements including: - Significantly improved performance on Windows, with various Windows specific features and improvements - Higher availability, with new semi-synchronous replication and Replication Heartbeat - Improved usability, with Improved index and table partitioning, SIGNAL/RESIGNAL support and enhanced diagnostics, including a new Performance Schema monitoring capability. For a more complete look at what's new in MySQL 5.5, please see the following resources: MySQL 5.5 is GA, Interview with Tomas Ulin: http://dev.mysql.com/tech-resources/interviews/thomas-ulin-mysql-55.html Documentation: http://dev.mysql.com/doc/refman/5.5/en/mysql-nutshell.html Whitepaper: What's New in MySQL 5.5: http://www.mysql.com/why-mysql/white-papers/whats-new-in-mysql-5-5/ If you are running a MySQL production level system, we would like to direct your attention to MySQL Enterprise Edition, which includes the most comprehensive set of MySQL production, backup, monitoring, modeling, development, and administration tools so businesses can achieve the highest levels of MySQL performance, security and uptime. http://mysql.com/products/enterprise/ For information on installing MySQL 5.5.39 on new servers, please see the MySQL installation documentation at http://dev.mysql.com/doc/refman/5.5/en/installing.html For upgrading from previous MySQL releases, please see the important upgrade considerations at: http://dev.mysql.com/doc/refman/5.5/en/upgrading.html MySQL Database 5.5.39 is available in source and binary form for a number of platforms from our download pages at: http://dev.mysql.com/downloads/mysql/ The following section lists the changes in the MySQL source code since the previous released version of MySQL 5.5. It may also be viewed online at: http://dev.mysql.com/doc/relnotes/mysql/5.5/en/news-5-5-39.html Enjoy! Changes in MySQL 5.5.39 (2014-07-31) Functionality Added or Changed * CMake support was updated to handle CMake version 3. (Bug #19001781) * The timed_mutexes system variable has no effect and is deprecated. Bugs Fixed * InnoDB: Opening an parent table that has thousands of child tables could result in a long semaphore wait condition. (Bug #18806829) * Partitioning: Selecting from a table having multiple columns in its primary key and partitioned by LIST COLUMNS(R), where R was the last (rightmost) column listed in the primary key definition, returned an incorrect result. (Bug #17909699, Bug #71095) * Replication: Quotation marks were not always handled correctly by LOAD DATA INFILE when written into the binary log. (Bug #18207212, Bug #71603) * Replication: A group of threads involved in acquiring locks could deadlock when the following events occurred: 1. Dump thread reconnects from slave; on master, a new dump thread tries to kill zombie dump threads; having acquired the thread's LOCK_thd_data, it is about to acquire LOCK_log. 2. Application thread executing show binary logs, having acquired LOCK_log and about to acquire LOCK_index. 3. Application thread executing PURGE BINARY LOGS; having acquired LOCK_index, it is about to acquire LOCK_thread_count. 4. Application thread executing SHOW PROCESSLIST (or SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST), having acquired LOCK_thread_count and about to acquire the zombie dump thread's LOCK_thd_data. This leads to the 4 threads deadlocking in the same order which the threads have been listed here. This problem arises because there are ordering rules for LOCK_log and LOCK_index, as well as rules for ordering LOCK_thread_count and LOCK_thd_data, but there are no rules for ordering across these two sets of locks. This was because the internal mysqld_list_processes() function invoked by SHOW PROCESSLIST acquired LOCK_thread_count for the complete lifetime of the function as well as acquiring and releasing each thread's LOCK_thd_data. Now this function takes a copy of the threads from the global thread list and performs its traversal on these, and only after releasing LOCK_thread_count. During this traversal, removal from the global thread list is blocked using LOCK_thd_remove such that the copies that would otherwise be destroyed by the removal remain valid during traversal. The locking order following this fix is shown here: LOCK_thd_remove -> LOCK_thd_data -> LOCK_log -> LOCK_index -> LOCK_th read_count (Bug #17283409, Bug #69954) * SHA and MD5 functions failed for operations using the internal filename character set and could cause a server exit. (Bug #18786138) * Large arguments passed to mysqldump could lead to buffer overflow and program exit. (Bug #18779944) * Compiler flags were not passed to DTrace, causing problems for 32-bit builds cross-compiled on 64-bit platforms. (Bug #18593044) * mysqladmin password masked the old password given on the command line, but not the new password. (Bug #18163964) * yaSSL code had an off-by-one error in certificate decoding that could cause buffer overflow. yaSSL code had an opendir() without a corresponding closedir(). (Bug #18178997, Bug #17201924) * MyISAM temporary files could be used to mount a code-execution attack. (Bug #18045646) * If a query had both MIN()/MAX() and aggregate_function(DISTINCT) (for example, SUM(DISTINCT)) and was executed using Loose Index Scan, the result values of MIN()/MAX() were set improperly. (Bug #17217128) * For UNION statements, the rows-examined value was calculated incorrectly. This was manifest as too-large values for the ROWS_EXAMINED column of Performance Schema statement tables (such as events_statements_current). (Bug #17059925) * Use of a nonmulti-byte algorithm for skipping leading spaces in multi-byte strings could cause a server exit. (Bug #12368495, Bug #18315770) * Deadlock could occur if three threads simultaneously performed INSTALL PLUGIN, SHOW VARIABLES, and mysql_change_user(). (Bug #71236, Bug #18008907, Bug #72870, Bug #18903155) * MySQL did not compile with Bison 3. A workaround is to downgrade to Bison 2. (Bug #71250, Bug #18017820, Bug #18978946) * Uninstalling and reinstalling semisynchronous replication plugins while semisynchronous replication was active caused replication failures. The plugins now check whether they can be uninstalled and produce an error if semisynchronous replication is active. To uninstall the master-side plugin, there must be no semisynchronous slaves. To uninstall the slave-side plugin, there must be no semisynchronous I/O threads running. (Bug #70391, Bug #17638477) * If there was a predicate on a column referenced by MIN() or MAX() and that predicate was not present in all the disjunctions on key parts earlier in the compound index, Loose Index Scan returned an incorrect result. (Bug #71097, Bug #17909656) * File permissions and line endings of several test and configuration files were made more consistent to avoid warnings from package checkers. (Bug #68521, Bug #16415173, Bug #16395459, Bug #68517, Bug #16415032, Bug #71112, Bug #17919313, Bug #71113, Bug #17919422) On behalf of Oracle/MySQL RE Team, Murthy Narkedimilli
Edited 1 time(s). Last edit at 08/05/2014 04:13AM by Surya Narayana Murthy Narkedimilli.
MySQL Community Server 5.5.39 has been released
August 01, 2014 01:43AM
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