… views open inside InnoDB Main thread process no. 3956, id 1157658976, state: sleeping Number of rows inserted 60790248, updated 11571576, deleted 0, read… this project from MySQL AB side) – to improve how Innodb read-ahead works by having more overlap between requests so thread would rarely…
Post: InnoDB thread concurrency
June 5, 2006 By 4 Comments
…threads) thread thrashing could be still observed even with limited innodb_thread_concurrency. This is why innodb_commit_concurrency variable was added in MySQL 5.0 innodb…
Post: Load management Techniques for MySQL
May 6, 2012 By 3 Comments
One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though… also often helps with monopolizing replication thread. For example if I need to delete old data instead of DELETE FROM TBL WHERE ts
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
… something like this: SELECT * FROM table WHERE deleted = 0 AND group_id IN (62715996, 62716592, …select,JOIN::exec,mysql_sel ect,handle_select,execute_sqlcom_select,mysql_execute_command,mysql_parse,…thread,clone P.S Disabling adaptive hash index makes things a lot worse in this workload and innodb…
Post: Can't Create Thread: Errno 11 (A Tale of Two Ulimits)
February 4, 2013 By 12 Comments
… your nproc changes directly in this file. Delete the file entirely (although it might …thread limit: (root@revolution 23:59:37)# service mysql restart Shutting down MySQL (Percona Server)… SUCCESS! Starting MySQL (… we have a high-traffic MySQL server with a very large InnoDB buffer pool, having to…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… accumulate or fill up the disk. #!/bin/bash # Begin by deleting things more than 7 days old find /root/tcpdumps/ -type… 1 fi host=$(mysql -ss -e ‘SELECT p.HOST FROM information_schema.innodb_lock_waits w INNER JOIN information_schema.innodb_trx b ON b.trx_id = w.blocking_trx_id INNER JOIN information_schema.processlist p on b.trx_mysql_thread…
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 5 Comments
… comes in to play when innodb_thread_concurrency is greater than zero. On a stock install of MySQL, here are some example queries… parent(id) -> ON DELETE CASCADE -> ) ENGINE=INNODB; — 0 Tickets Used Query OK, 0 rows affected (0.00 sec) mysql> INSERT INTO parent (id…=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…
Comment: MySQL Server Memory Usage
September 1, 2006 By 21 Comments
…’ ‘Com_create_table’, ’31′ ‘Com_dealloc_sql’, ’0′ ‘Com_delete‘, ’348788′ ‘Com_delete_multi’, ’1′ ‘Com_do’, ’0′ ‘Com_drop_db’, ’0… AVAILABLE #innodb_log_buffer_size=8M # Lowered from 32M according to MySQL innodb_additional_mem_pool_size=20M innodb_file_io_threads=4 innodb_lock_wait_timeout=15 # CHANGED from 50 innodb_log_files_in_group=3 innodb…
Post: Reasons for run-away main Innodb Tablespace
June 10, 2010 By 2 Comments
… following can be helpful: mysql> select * from innodb_rseg; +———+———-+———-+———+————+———–+ | rseg_id | space_id |… such processes in chunks, updating/deleting may be thousands of rows… also use innodb_use_purge_thread to use dedicated purge thread, which works…
Post: INSERT INTO ... SELECT Performance with Innodb tables.
July 12, 2006 By 22 Comments
… look in SHOW INNODB STATUS: —TRANSACTION 0 42304626, ACTIVE 14 sec, process no 29895, OS thread id 2894768 updating or deleting mysql tables in… thread id 4058032 fetching rows, thread declared inside InnoDB 3 mysql tables in use 1, locked 1 2539 lock struct(s), heap size 224576 MySQL thread…
