…innodb_log_file_size slows down recovery. During startup after crash Innodb scans log files to find log…number of unflushed pages in innodb buffer pool and its size as well as …undo” phase can’t be reduced by sizing your log files. Even more undo phase can be slower with small log files. Undo…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… will also grow and innodb_max_purge_lag will become your friend. “undo n:o” will show the undo log record number which purge… in log files. By monitoring log sequence number and value up to which logs have been flushed you can check if your innodb_log_buffer_size is optimal – if you see more than 30% of log buffer size being…
Post: How to estimate time it takes Innodb to Recover ?
May 9, 2007 By 7 Comments
… should normally set innodb_log_file_size large. We however usually recommend caution as it may significantly increase recovery time if Innodb needs to… if logs are of reasonable size and wikipedia has 40 minutes or so with innodb_log_file_size=256MB. In other cases I know same log… more sequential order. Besides log replay phase there is also phase of flushing dirty buffers to the disk and undo phase – rolling back…
Post: Copying InnoDB tables between servers
July 31, 2009 By 10 Comments
…: innodb_log_files_in_group = 1 xtrabackup: innodb_log_file_size = 92684288 xtrabackup: Starting InnoDB instance for recovery. xtrabackup: Using 8589934592 bytes for buffer…InnoDB: in total 107 row operations to undo InnoDB: Trx id counter is 0 1560320 …. id 0 1559932, 13 rows to undo InnoDB…
Post: Estimating Undo Space needed for LVM Snapshot
June 9, 2008 By 5 Comments
…to be read from undo space will require disk seek, unless they are buffered already. This means … you have 10GB database size (including logs etc) you will not need 18GB undo snapshot no matter how … logs in the backup and you do not want query log and general logs anyway. However DO place Innodb Log…
Post: How InnoDB handles REDO logging
February 3, 2011 By 18 Comments
… control the transaction log record size, as …innodb_flush_log_at_trx_commit = 1 /* Write log buffer to log and flush to disk */ innodb_flush_log_at_trx_commit = 2 /* Write log buffer to log…UNDO-REDO protocol InnoDB also records UNDO information, however that is stored outside of the transaction log…
Post: XtraDB: The Top 10 enhancements
August 13, 2009 By 5 Comments
…log files (innodb_log_file_size), which is worse for performance. Â In a simple test, XtraDB recovered ten times faster (see docs). InnoDB…log file (see docs). Insert Buffer control – The insert buffer is a great feature of InnoDB…see docs). Additional undo slots – In the built-in InnoDB, the number …
Post: My Innodb Feature wishes
May 4, 2006 By 30 Comments
…undo pages might be avoided if possible as we know they are going to be purged. Long Rows. One ugly thing Innodb… much sense to have more than one log flush thread. The other big lacking (especially …will complicate buffer management a bit but Innodb is already to deal with 2 page sizes by supporting …
Post: Percona-XtraDB-9.1: released and new coming features
March 17, 2010 By 14 Comments
…scalability Separate purge thread Limited size of data dictionary in memory Increased number of concurrent write transactions (undo slots) ( up to …Import / export of buffer_pool Transactional replication Show internal InnoDB data dictionary Show InnoDB locking/io profiling in slow.log I hope you …
Post: Connecting orphaned .ibd files
May 13, 2011 By 12 Comments
…InnoDB can organize tablespaces. First is when all data, indexes and system buffers …SIZE in the source code). Let’s take a look at the page header: InnoDB Page Header Name Size…log serial number of page’s latest log record FIL_PAGE_TYPE 2 current defined types are: FIL_PAGE_INDEX, FIL_PAGE_UNDO_LOG…
