… ENGINE INNODB STATUS information as follow: —TRANSACTION 0 27638, ACTIVE 1207 sec, process no 2909, OS thread id 1100101952 inserting mysql tables in use 1, locked 1 LOCK WAIT 2 lock struct(s), heap size 1216, 1 row lock(s) MySQL thread id 31929…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…table lock priority problem with pending WRITE query blocks any READ queries to execute on the table. mysql…Innodb tables and you’re not actively changing users, stored procedures etc (which are stored in MyISAM tables…
Post: InnoDB's gap locks
March 27, 2012 By 15 Comments
…Lock wait timeout exceeded; try restarting transaction transaction2 > INSERT INTO t VALUES(29); ERROR 1205 (HY000): Lock wait…MySQL thread id 3, OS thread handle 0x7f84a78ba700, query id 163 localhost msandbox TABLE LOCK table `test`.`t` trx id 72C lock mode IX RECORD LOCKS…
Comment: Innodb Performance Optimization Basics
March 28, 2012 By 70 Comments
… tables are in InnoDB with MySQL 5 and RHEL 5. Its a 32 bit machine with 12 Gb RAM. The imp param for InnoDB… innodb_additional_mem_pool_size = 2M innodb_log_file_size = 65M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 1 innodb_lock_wait_timeout = 50 A count command with approx 3 million records is taking too long and all my transactions are locked. select…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…table_definition_cacheblogpercona.commanual table_lock_wait_timeoutblogpercona.commanual Table_locks_immediateblogpercona.commanual Table_locks_waitedblogpercona.commanual table_open_cacheblogpercona.commanual table…
Post: INFORMATION_SCHEMA tables in the InnoDB pluggable storage engine
May 24, 2008 By Leave a Comment
…: mysql> SHOW TABLES FROM INFORMATION_SCHEMA LIKE ‘INNODB%’; +—————————————-+ | Tables_in_INFORMATION_SCHEMA (INNODB%) | +—————————————-+ | INNODB_CMP | | INNODB_CMP_RESET | | INNODB_CMPMEM | | INNODB_CMPMEM_RESET | | INNODB_LOCK_WAITS | | INNODB…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
…. If we’re running Innodb with MySQL we can use Innodb_data_reads , Innodb_data_writes, Innodb_os_log_fsyncs for … level locks, etc. The ratio between Wait Time and CPU time is very helpful to see how “wait free … scan 0% yes, 99% no # Tmp table 1% yes, 98% no # Tmp table on 1% yes, 98% no In …
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… data, then other transactions could block and fail with a lock wait timeout. The problem is, it can be very difficult to… blocking others. There are some INFORMATION_SCHEMA tables that make this simple. Just query the tables, and if something is blocked, find… exit 1 fi host=$(mysql -ss -e ‘SELECT p.HOST FROM information_schema.innodb_lock_waits w INNER JOIN information_schema.innodb_trx b ON…
Post: Table locks in SHOW INNODB STATUS
June 8, 2010 By 1 Comment
… 2 lock struct(s), heap size 368 MySQL thread id 8, query id 164 localhost root TABLE LOCK table `test/t1` trx id 0 4872 lock mode IX This output gives us an impression Innodb has taken table lock on test/t1 table… not worry intention table locks you may observe in SHOW INNODB STATUS output, they almost never would be cause of your lock waits or deadlocks.
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
…overly full. Too many deadlocks. Deadlocks (and lock wait timeouts, covered in another plugin) are … pmp-check-mysql-innodb plugin checks for several indicators of severe internal problems within InnoDB, such … trying to open or close tables can indicate LOCK_open contention. Replication is delayed or…
