… separate dedicated purge thread and in MySQL 5.6.2 one can have multiple dedicated purge threads. Percona Server 5.1 supports multiple purge threads too… any, do the additional purge threads bring. The test workload makes a long history list and then lets purge thread(s) work through it… difference and that the purge thread started working through the history list, at the cost of TPS. Multiple dedicated purge threads even with the…
Post: Purge Thread Spiral of Death
June 10, 2010 By 2 Comments
… frequently you have purge not being the problem at all and when out of no where you can see purge thread being unable… is when problems often starts to happen. Now instead of purge thread simply operating in memory it has to perform IO which… can be controlled), using innodb_max_purge_lag or enable separate purge thread (or threads) via innodb_use_purge_thread if you’re running Percona Server…
Post: Tuning for heavy writing workloads
October 14, 2009 By 9 Comments
… (single purge_thread similar to Dimitri’s) “xtra p_t 4″: XtraDB 1.0.4-new (4 purge threads) The graphs show… The purge thread (> 0) helps to stabilize the throughput greatly. Increasing the purge threads can suppress the strong…
Post: Reasons for run-away main Innodb Tablespace
June 10, 2010 By 1 Comment
… changes. Purge Thread Falling Behind This is the most dangerous reason. It is possible for database updates happen faster than purge thread can purge records… first you can use innodb_max_purge_lag to make a threads doing modifications slow down if purge thread can’t keep up. This…’re running XtraDB you can also use innodb_use_purge_thread to use dedicated purge thread, which works a bit faster as it does…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…thread_cache_sizeblogpercona.commanual thread_concurrencyblogpercona.commanual thread_handlingblogpercona.commanual thread_stackblogpercona.commanual Threads_cachedblogpercona.commanual Threads_connectedblogpercona.commanual Threads_createdblogpercona.commanual Threads…
Comment: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
… here.. then, regarding Purge Thread itself – for anyone expecting a “normal” or “as designed” InnoDB work should always keep a Purge Thread enabled! – I… I’m still preferring a combination of “Purge Thread + max purge lag setting” rather several Purge Threads as it gave me better performance results in…
Comment: MySQL 5.5.8 and Percona Server: being adaptive
December 20, 2010 By 25 Comments
… is to make it more accurate. As you know master thread does the adaptive_flushing check every second in a loop… don’t think purge should be a concern. But to keep master thread free of getting stuck in purge maybe it is a good idea to use innodb_purge_threads = 1.
Comment: Which adaptive should we use?
September 17, 2009 By 14 Comments
… and your purge_thread. The history list length never exceed 20000 during any TPC-C test at the server. And purge_thread affect 3~4% improve of throughput and it seems to purge aggressively (not exceed 1000). And about 32 threads, the server has 16 cores and the each thread of the…
Post: Percona Server 5.1.57-12.8 Stable Release
June 8, 2011 By 10 Comments
… for innodb_use_purge_threads has been corrected to 32 (maximum number of parallel threads in a parallelized operation). The innodb_purge_thread patch accepted a value up to 64 for the innodb_use_purge_thread variable…
Post: How to load large files safely into InnoDB with LOAD DATA INFILE
July 3, 2008 By 28 Comments
… the load — but from other transactions’ changes too; the purge thread cannot purge them, so everything gets bloated and slow. Even simple SELECT… scan through lots of obsolete, but not-yet-purged, row versions. Later, the purge thread will have to clean these up. This is…
