… 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… a good idea. It also often helps with monopolizing replication thread. For example if I need to delete old data instead…
Post: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
… 2 innodb_flush_method = O_DIRECT innodb_max_dirty_pages_pct = 50 innodb_io_capacity = 800 innodb_read_io_threads = 8 innodb_write_io_threads = 4 innodb… = InnoDB, PARTITION p10 VALUES LESS THAN MAXVALUE ENGINE = InnoDB) */ Also, I ran 5 instances of iiBench simultaneously to simulate 5 concurrent…
Comment: InnoDB thread concurrency
March 19, 2012 By 4 Comments
… thread) I/O thread 9 (thread id: 18587) state: waiting for completed aio requests (write thread) but i found that the value of the innodb_thread_concurrency is 8. so, what is wrong with this sitution? what the innodb_thread_concurrency real…
Post: InnoDB's gap locks
March 27, 2012 By 14 Comments
… of the most important features of InnoDB is the row level locking. This feature provides better concurrency under heavy write load but… row lock(s), undo log entries 1 MySQL thread id 3, OS thread handle 0x7f84a78ba700, query id 163 localhost msandbox TABLE LOCK… have lot of gaps locks in your transactions affecting the concurrency and the performance you can disable them in two different…
Post: InnoDB thread concurrency
June 5, 2006 By 4 Comments
…_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_thread_sleep_delay > 0) { thread_sleep(innodb_thread…
Post: Mess with innodb_thread_concurrency
May 12, 2006 By 1 Comment
….19 the meaning of innodb_thread_concurrency variable was changed (yeah, again). Now innodb_thread_concurrency=0 means unlimitied count of concurrent threads inside InnoDB. It’s logical, but… 5.0.8 for unlimited threads you had to set innodb_thread_concurrency over 500 (and default value for innodb_thread_concurrency was 8 ). Starting with MySQL…
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 4 Comments
… innodb_log_files_in_group=2 innodb_log_file_size=1900M innodb_thread_concurrency=16 innodb_flush_method = O_DIRECT innodb_write_io_threads=8 innodb_read_io_threads=8 innodb_io_capacity=500 innodb_max…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
…: What’s the status of INNODB in 5.1.x? Specifically: What’s the current status of innodb_thread_concurrency ? Is it suggested to set this value to a LARGE value (somewhat like 200) for additional throughput? HT: ha_innodb…_ULONG(thread_concurrency, srv_thread_concurrency, PLUGIN_VAR_RQCMDARG, “Helps in performance tuning in heavily concurrent environments. Sets the max\ imum number of threads allowed inside InnoDB…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…. “Thread declared inside 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 at the same time. If thread is not runniing inside innodb kernel…
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
… MyISAM / InnoDB: libexec/mysqld –no-defaults –user=root –key-buffer-size=1500M –innodb-buffer-pool-size=1500M –innodb-log-file-size=100M –innodb-thread-concurrency=8… query for 1, 4, 16, 64, 128, 256 concurrent threads. 3. For each thread perform a warm-up run (duration 180 sec), and…
