… thread id 188790, query id 14796224615 host.domain.com 127.0.0.1 root It was running over 4 hours so Innodb… transaction isolation affects purging ? Innodb is smart and trying to purge data as soon as possible. In default (REPEATABLE-READ) mode Innodb has to… and Innodb is smart enough to figure how far it can purge the data, it even can be seen in SHOW INNODB STATUS…
Post: MySQL 5.6: Improvements in the Nutshell
January 27, 2013 By 16 Comments
… Transactions – Concurrent Innodb data file extension – Non-Recursive Deadlock Detection – Faster Locking Primitives – Improved Innodb Thread Concurrency – Multiple background Purge Threads – Improved Purge lag control (now works) – Split of “Kernel Mutex” – Data Dictionary Cache – Improved Adaptive Flushing – Page Cleaner/Separate Flush Thread…
Comment: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
Peter, don’t forget that “innodb_max_purge_lag” is dynamic – so if you’ve some planned night … the needed value once activity is back to the normal.. Purge has an important cost, and for the moment all proposed solution so speed-up the purge are also considerably slowing down TPS level.. – that’s why “Purge Thread + max purge lag” is looking as…
Post: My Innodb Feature wishes
May 4, 2006 By 30 Comments
… as we know they are going to be purged. Long Rows. One ugly thing Innodb currently does is storing first 700 bytes… 
I/O On Linux you’re currently limited to innodb_file_io_threads=4. Some people do not know it but setting… I will list it. Basically Innodb has problems scaling both with large number of active threads and with large number of CPUs…
Comment: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… global value. innodb_purge_batch_size is a performance enhancement, Should also be used in 5.5 to reduce purge overhead. innodb_open_files…_cache setting because we expect most tables to be InnoDB and use innodb_file_per_table. sql_mode also uses STRICT_TRANS…://blogs.oracle.com/supportingmysql/entry/mysql_server_5_6_default . thread_cache_size is quite low, and dynamic based on max…
Post: When does Innodb Start Transaction ?
January 11, 2011 By 9 Comments
… INNODB table you can see transaction is started: —TRANSACTION F56AED, ACTIVE 4 sec, process no 23727, OS thread id 139753656395520 MySQL thread id 112, query id 411 localhost root show innodb status Trx read view will…, especially in repeatable-read mode as it will require innodb not to purge any old row versions from start of transaction until…
Post: Percona-XtraDB-9.1: released and new coming features
March 17, 2010 By 14 Comments
… Fast recovery Improved IO path Improved rollback segment scalability Separate purge thread Limited size of data dictionary in memory Increased number of… / export of buffer_pool Transactional replication Show internal InnoDB data dictionary Show InnoDB locking/io profiling in slow.log I hope you…
Comment: MySQL Replication vs DRBD Battles
May 1, 2008 By 12 Comments
… buffer cache + pending IO from insert buffer + pending IO for purge thread). When the max is exceeded the server can favor background…. Is there any parallelism or concurrency (multiple threads or multiple IOs pending) in InnoDB crash recovery code? The Google patch had more…). This was done using the same replication protocol — the IO thread would copy events into the relay log and the mirrored…
Comment: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
Dimitri, innodb_max_purge_lag can indeed be good for uniform workloads this is … history size to be cleaned up eventually, which requires multiple purge threads for IO bound processing.
Post: Recovering Innodb table Corruption
July 4, 2008 By 22 Comments
… Innodb tablespace got corrupted. In such cases Innodb will typically print something like this: InnoDB: Database page corruption on disk or a failed InnoDB… with innodb_force_recovery=1 080704 0:22:53 InnoDB: Assertion failure in thread 1158060352 in file btr/btr0btr.c line 3235 InnoDB: Failing… from simple Innodb Table Corruption. In more complex cases you may need to use higher innodb_force_recovery modes to block purging activity…
