…In my testing I discovered that innodb_old_blocks_time had an effect on performance of the… low concurrency SSB tests when Peter blogged about the importance of performance at low concurrency. The…mnt/mysql56/data basedir=/usr/local/mysql socket=/var/lib/mysql/mysql.sock user=justin innodb_buffer_pool…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
… is then a matter of copying a relatively small memory block which, depending on many factors, can be from few times… scan in MySQL 5.5 basically kills throughput on high concurrency. The picture changes dramatically when the read-only optimization in MySQL 5… “read-only transactions” optimization in MySQL 5.6 are nice ways to improve scalability in highly concurrent workloads. We also have plans…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… amazing MySQL manual, especially the option and …completion_typeblogpercona.commanual Compressionblogpercona.commanual concurrent_insertblogpercona.commanual connect_timeoutblogpercona.commanual…commanual Key_blocks_not_flushedblogpercona.commanual Key_blocks_unusedblogpercona.commanual Key_blocks_…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…SCHEMA_MAX_THREAD_INSTANCES | 1000 | 224 | | SOCKET | /tmp/mysql_sandbox5530.sock | /tmp/mysql_sandbox5610.sock | | INNODB_FILE_PER_TABLE | OFF | ON | | … blocking old insecure one. Good. innodb_concurrency_tickets has been increased from 500 to 5000. If you’re using innodb_thread_concurrency…
Post: Load management Techniques for MySQL
May 6, 2012 By 3 Comments
… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though… to use. Do push concurrency too high Many developers will test script with multiple level of concurrency and find out doing work… to serve other users too you typically need to reduce concurrency to where it does not overload the system. Unless it…
Post: Side load may massively impact your MySQL Performance
November 13, 2011 By 7 Comments
… and many things can be happening concurrently. It is very typical to hear complains about MySQL interactive performance – serving simple standard web… to enable it separately. There is a variable innodb_old_blocks_time which specifies amount of milliseconds which needs to pass… innodb_old_blocks_time to non zero value, if not I would strongly suggest changing default from zero in MySQL 5.6…
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 5 Comments
…_thread_concurrency is greater than zero. On a stock install of MySQL, here are some example queries and the corresponding number of concurrency tickets used for each: mysql> CREATE TABLE test… block the PK lookups until one of them is subject to a concurrency check or complete execution and exit InnoDB. If innodb_concurrency…
Post: Concurrent inserts on MyISAM and the binary log
May 14, 2008 By 7 Comments
… interesting surprise with concurrent inserts into a MyISAM table. The inserts were not happening concurrently with SELECT statements; they were blocking and the… MySQL manual actually says this, but not in the clearest way. It just says If you are using the binary log, concurrent…’ll see this: Read lock without concurrent inserts That read lock is what’s blocking the concurrent inserts from happening. There’s no…
Post: MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 11 Comments
… work very well when you don’t need high concurrency from your MySQL database. When you do, the limitations on the core… effective ceiling in today’s largest EC2 instances. That is concurrency inside the database, not at the application level. You can… this very well, because I/O tends to be a blocking operation in InnoDB, and this can cause stalls ranging from…
Post: Effect from innodb log block size 4096 bytes
January 3, 2011 By 19 Comments
In my post MySQL 5.5.8 and Percona Server: being adaptive I mentioned that I used innodb-log-block-size=4096 in Percona Server to get better throughput, but later Dimitri in his article MySQL Performance: Analyzing…_file_size=4G innodb_adaptive_checkpoint=keep_average innodb_thread_concurrency=0 innodb_flush_method = O_DIRECT innodb_read_ahead = none…
