…used: ## InnoDB options innodb_buffer_pool_size = 55G innodb_log_file_size = 1G innodb_log_files_in_group = 4 innodb_buffer_pool_instances = 4 innodb_…reduce contention problems caused by buffer pool mutexes, using “estimate” checkpoint method to reduce chances of log flush storms and disabling…
Comment: How to recover a single InnoDB table from a Full Backup
March 22, 2012 By 7 Comments
… using the innobackupex-1.5.1 command. I have the innodb_file_per_table directive set in the my.cnf configuration… have the backup folder which contains xtrabackup log files, xtrabackup checkpoint file and a folder for my database (called tools) which… to view/access ONLY MYISAM table – but none of the InnoDB tables. Is there something which I am missing? Do I…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 5 Comments
… Innodb Log Checkpointing So, first of all, what can we see about Innodb log checkpointing and what does it tell us? mysql> SHOW ENGINE INNODB… transaction logs; our Checkpoint age cannot exceed this without blocking client operations in Innodb to flush dirty buffers. Max checkpoint age appears to…
Post: InnoDB Flushing: Theory and solutions
April 4, 2011 By 23 Comments
… a crash. In fact, InnoDB has two protection points: “async” and “sync”. When checkpoint_age reaches “async”, InnoDB tries to flush as many… pages and return checkpoint_age to a point before “async”. This is done to prevent checkpoint_age from exceeding innodb_log_file_size. These are both abnormal operational stages for InnoDB and should be…
Post: Adaptive checkpointing
November 13, 2008 By 9 Comments
… method, because innodb_max_dirty_pages_pct and innodb_io_capacity are independent to the checkpoint age. <innodb_adaptive_checkpoint(new patched parameter) & innodb_io_capacity> The last is the case of using innodb_adaptive_checkpoint instead of innodb_max…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
… in MySQL 5.1 Q15: How frequently does Innodb fuzzy checkpointing is activated HT: InnoDB flushes about 128 dirty pages per flush. That… fuzzy checkpointing one of little known aspects of Innodb operations while I see it causing problems every so often. Q16: How Innodb decided… checkpointing rate? Postgres exposes this data and allows the user to tune the checkpointing values. HT: Hmm… we could tune the way InnoDB…
Post: How to estimate time it takes Innodb to Recover ?
May 9, 2007 By 7 Comments
… better to understand how Innodb recovery works. When Innodb recovers from logs it finds the last checkpoint time. Innodb has fuzzy checkpointing and yet there… buffer pool flushes are not predictable. As Innodb is scanning log files from last checkpoint time it looks at records and checks…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… in log buffer as well as when last checkpoint was performed. Innodb uses fuzzy checkpointing so this line hold log sequence, all changes… currently active, state of Innodb main thread which controls scheduling of number of system operations – flushing dirty pages, checkpointing, purging, flusing logs…
Post: How InnoDB handles REDO logging
February 3, 2011 By 18 Comments
Xaprb (Baron) recently blogged about how InnoDB performs a checkpoint , I thought it might be useful to explain another important … been executed as we will start recovery from the last checkpoint.InnoDB achieves this by reading the LSN of the page and…). How are the REDO records applied? InnoDB processes the REDO records from the last checkpoint, each record’s LSN is compared against…
Post: Innodb Fuzzy checkpointing woes
May 10, 2006 By Leave a Comment
… bug. Here is what is happening. Then planing fuzzy checkpoints Innodb assumes kind of uniform distribution of LSN (Log Sequence Number… worse. Technically if there are too many dirty pages Innodb should start doing checkpoints more actively, this is if there are more… checkpoint kind flushes, which would avoid uneeded IO. One more related problem Innodb has – too many hard coded numbers. For example Innodb…
