… tune the thread concurrency inside MySQL with the variable thread_concurrency. Our advice is: stop wasting your time, it does nothing on GNU/Linux 
Some of the biggest GNU/Linux…
Post: thread_concurrency doesn't do what you expect
June 4, 2012 By 3 Comments
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…DIR | /mnt/nfs/dist/mysql-5.5.30-linux2.6-x86_ | /mnt/nfs/dist/mysql-5.6.10-linux-glibc2. | | PERFORMANCE_SCHEMA_…innodb_thread_concurrency this will reduce overhead associated with grabbing and releasing innodb_thread_concurrency slot but will increase potential starvation of queued threads …
Post: Interesting MySQL and PostgreSQL Benchmarks
November 30, 2006 By 20 Comments
… up with number of threads about matches number of Cores/Threads and stays at this level at higher concurrency. MySQL with Innodb shows its… this picture Linux vs Solaris comparison is also pretty interesting. With MySQL Linux has higher peak but Solaris suffers less with increased concurrency. Note…
Post: How Innodb Contention may manifest itself
July 28, 2011 By 1 Comment
… newer MySQL version or doing application/architecture changes. Reducing number of competing threads (such as limiting number of Apache Children) as well as adjusting innodb_thread_concurrency … number. With modern hardware and modern Linux process scheduler you can be looking …
Post: Linux schedulers in tpcc like benchmark
January 30, 2009 By 19 Comments
… RedHat / CentOS 5.x may be not so good for MySQL. And yesterday one customer reported that just changing cfq to…_file_size=128M innodb_thread_concurrency=0 innodb_flush_method = O_DIRECT innodb_write_io_threads=4 innodb_read_io_threads=4 innodb_io…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
… already works – it is global MySQL Server option, though it may have problems on Linux if you lock very large…MYSQL_SYSVAR_ULONG(thread_concurrency, srv_thread_concurrency, PLUGIN_VAR_RQCMDARG, “Helps in performance tuning in heavily concurrent environments. Sets the max\ imum number of threads…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… thread id 1148250464, thread declared inside InnoDB 442 mysql tables in use 1, locked 0 MySQL thread…thread concurrency allowing only innodb_thread_concurrency threads to run inside Innodb kernel at the same time. If thread… threads running queries. On Unix/Linux you will always see 4 helper threads,…
Post: MyISAM concurrent insert
June 13, 2006 By 12 Comments
… on main platforms (Linux, Solaris, Windows) rw…threads Quadxeon with enabled concurrent-insert Quadxeon –skip-concurrent-insert Sun V40z with enabled concurrent-insert Sun V40z –skip-concurrent…MySQL developers are working on CPU-depended rw-locks implementstation, this will be available in MySQL…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
…information): # Aspersa System Summary Report ############################## Platform | Linux Release | Ubuntu 10.04.2 LTS (lucid…alignment, not different MySQL configurations, I didn’t try out different MySQL versions or …to 15% in case of 8 threads running concurrently. Because the customer was …
Comment: Database problems in MySQL/PHP Applications
November 6, 2006 By 13 Comments
… -9 is run. Our mysql db contains a mix of innodb and myism tables and run on linux with 16gigs or ram. Here is our my.cnf # sammple MySQL config file for very large…_timeout=300 thread_cache = 40 max_connections=500 query_cache_size = 2000M # Try number of CPU’s*2 for thread_concurrency thread_concurrency = 8 ft…
