…MySQL in wild. I also wanted to share some troubleshooting techniques I use. Plot Memory Usage First I would like to see MySQL memory…Innodb Memory Usage Finally it is often helpful to check how much memory Innodb…
Post: How much memory Innodb locks really take ?
July 13, 2006 By 11 Comments
…INSERT … SELECT I decided to check is Innodb locks are relly as efficient in terms …locked row; Now lets see how much exclusinve locks take: mysql> begin; Query OK, 0 rows affected (0.00 sec) mysql…memory is using locking all the rows – so all rows are locked from the page. In other test we’ll lock…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
… on MySQL server. Let’s take a recent 5.1 bzr version (pre-5.1.61) and a single test, innodb_plugin.innodb…_reset_lock word is a memory barrier, that is when we read the waiters field next, the read must be serialized in memory…, I’d consider backporting and using MySQL 5.5 atomic operation primitives with proper memory barriers, so that there is no need…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL…innodb_flush_methodblogpercona.commanual innodb_force_recoveryblogpercona.commanual Innodb_have_atomic_builtinsblogpercona.commanual innodb_io_capacityblogpercona.commanual innodb_lock_wait_timeoutblogpercona.commanual innodb_locks_unsafe_for_binlogblogpercona.commanual innodb…shared_memory_base…
Post: How much memory Innodb Dictionary can take ?
May 6, 2010 By 3 Comments
…memory Innodb will …mysql> select count(*) from INNODB_SYS_TABLES; +———-+ | count(*) | +———-+ | 48246 | +———-+ 1 row in set (8.04 sec) mysql> select count(*) from INNODB…Lock system 2659016 (2657176 + 1840) Recovery system 0 (0 + 0) Threads 408536 (406936 + 1600) Dictionary memory…
Post: How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
… days need to consider the added memory for InnoDB: specifically, the buffer pool. (There’s also an innodb_additional_mem_pool_size but…: mysql> set @a := repeat(‘a’, 1024 * 1024 * 100); Query OK, 0 rows affected (2.34 sec) mysql> select get_lock(@a, 1); +—————–+ | get_lock…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
…’re running Innodb with MySQL we can use Innodb_data_reads , Innodb_data_writes, Innodb_os_log…is to compare systems with different memory amount having same workload. You …======= ======= ======= ======= ======= ======= # Exec time 8338s 1us 284s 5ms 13ms 298ms 185us # Lock time 71s 0 3ms 39us 54us …
Post: MySQL Binaries Percona build10
December 11, 2008 By 12 Comments
…innodb_locks_held.patch | Add locks held, remove locked records in SHOW INNODB STATUS | 1.0 | Baron Schwartz | GPL | Bug #29126 fix | | microslow_innodb…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
… pmp-check-mysql-innodb plugin checks for several indicators of severe internal problems within InnoDB, such … open or close tables can indicate LOCK_open contention. Replication is delayed or stopped…memory plugin checks for a single process consuming too much memory and/or for too little free memory…
Post: SELECT LOCK IN SHARE MODE and FOR UPDATE
August 6, 2006 By 51 Comments
Baron wrote nice article comparing locking hints in MySQL and SQL Server. In MySQL/Innodb LOCK IN SHARE MODE and SELECT FOR UPDATE are more… missing in Locking implementation of Innodb are: Lock table Innodb can lock tables but it will still need to set row level locks which is memory and…
