InnoDB has an oft-unused parameter innodb_concurrency_tickets that seems widely misunderstood. From the docs: “The number of threads that can enter InnoDB concurrently is determined by the innodb_thread_concurrency…
Post: InnoDB thread concurrency
June 5, 2006 By 4 Comments
…->n_tickets_to_enter_innodb > 0) { thread->n_tickets_to_enter_innodb–; ENTER; } retry: if (entered_thread < innodb_thread_concurrency) { entered_threads++; thread->n_tickets_to_enter_innodb = innodb_concurrency_tickets; ENTER; } if (innodb…
Post: thread_concurrency doesn't do what you expect
June 4, 2012 By 3 Comments
… of threads that runs concurrently you should read about innodb_thread_concurrency: http://www.mysqlperformanceblog.com/2011/07/28/how-innodb-contention-may-manifest…/05/24/tuning-innodb-concurrency-tickets/ innodb_thread_concurrency places a limit on the number of threads that can be running inside InnoDB. The default value…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… | | INNODB_CONCURRENCY_TICKETS | 500 | 5000 | | INNODB_PURGE_THREADS | 0 | 1 | | INNODB_OPEN_FILES | 300 | 2000 | | INNODB_DATA_FILE_PATH | ibdata1:10M:autoextend | ibdata1:12M:autoextend | | INNODB_PURGE… old insecure one. Good. innodb_concurrency_tickets has been increased from 500 to 5000. If you’re using innodb_thread_concurrency this will reduce overhead…
Comment: Tuning InnoDB Concurrency Tickets
May 26, 2010 By 5 Comments
Ryan, I am not sure I understand why higher innodb_concurrency tickets will reduce throughput ? For me it looks opposite – the higher … less “interruptions” while running queries and less overhead while checking concurrency. It will however increase variance – the larger is the value…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
….commanual innodb_change_bufferingblogpercona.commanual innodb_checksumsblogpercona.commanual innodb_commit_concurrencyblogpercona.commanual innodb_concurrency_ticketsblogpercona.commanual innodb_data_file_pathblogpercona.commanual Innodb_data_fsyncsblogpercona.commanual innodb_data…
Comment: MySQL on Amazon RDS part 2: Determining Peak Throughput
March 28, 2011 By 4 Comments
… 2097152 innodb_autoextend_increment 8 innodb_autoinc_lock_mode 1 innodb_buffer_pool_size 55050240000 innodb_change_buffering inserts innodb_checksums ON innodb_commit_concurrency 0 innodb_concurrency_tickets 500 innodb_data_file_path ibdata1:10M:autoextend innodb_data_home_dir /rdsdbdata/db/innodb innodb_doublewrite ON innodb_fast…
Comment: InnoDB thread concurrency
August 29, 2008 By 4 Comments
[...] “Killed”, but never dying. Based on what I’d read in High Performance MySQL, and articles like this one, I tried twiddling with innodb_thread_concurrency, innodb_concurrency_tickets, and [...]
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… InnoDB 400″ means thread is running inside Innodb kernel and still has 400 tickets to use. Innodb tries to limit thread concurrency allowing only innodb_thread_concurrency threads to run inside Innodb kernel…
Comment: InnoDB thread concurrency
August 18, 2011 By 4 Comments
Does a thread which “ENTER” cause (thread->n_tickets_to_enter_innodb > 0) is include in “entered_thread” ? Does it mean we can have more thread than innodb_thread_concurrency which inside innodb_kernel ? suppose innodb_thread_concurrency=8, 9 threads have free tickets and all of them ENTER.
