… of write size. InnoDB writes to the log files in multiples of 512 bytes. Mark Callaghan explained this and some of its performance implications here. How many big writes does InnoDB… So, in sum, we see that about 3/4ths of InnoDB log file writes on this workload are 512 or 1024 bytes. (It…
Post: Effect from innodb log block size 4096 bytes
January 3, 2011 By 19 Comments
…size=26G innodb_data_file_path=ibdata1:10M:autoextend innodb_file_per_table=1 innodb_flush_log_at_trx_commit=2 innodb_log_buffer_size=8M innodb_log_files_in_group=2 innodb_log_file_size=4G innodb…
Post: Measuring the amount of writes in InnoDB redo logs
October 8, 2012 By 4 Comments
… a good InnoDB log file size is key to InnoDB write performance. This can be done by measuring the amount of writes in the redo logs. You… is that while Innodb_os_log_written is incremented when the log file is written, the LSN is incremented when the log buffer is written…
Post: Binary log file size matters (sometimes)
May 24, 2012 By 6 Comments
… MySQL status counters, innodb status, memory info …performance impact. However, somehow I have noticed that pt-stalk kick-off time matched that of binary logs…size in size, new binary log is created and, if expire_logs_days is not zeroish, log files older than expire_logs_days are removed. &LOCK_log…
Post: How long is recovery from 8G innodb_log_file
December 22, 2010 By 11 Comments
… support of innodb_log_file_size > 4G. This test was done using Percona Server 5.5.7, but the same performance expected for InnoDB-plugin and… InnoDB: Rollback of non-prepared transactions completed that is 14min 57sec I think this time is acceptable as trade-off for performance…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… your concerns are at this stage. Is it the current performance, future performance, scalability, ability to recover from disasters? We also want… is the absence of innodb_log_file_size. I won’t give you a full rundown over every option in the file. But again, you… the error log is interesting and needs to be investigated. You might find that there are InnoDB tables whose .frm files exist but…
Post: InnoDB Flushing: a lot of memory and slow disk
March 31, 2011 By 57 Comments
… benchmark (100W ~ 10GB of data, 12G innodb_buffer_pool_size, 1G innodb_log_file_size), MySQL 5.5.10 with innodb_adaptive_flushing=ON (default)). The problem… a result of how it works, instead of performing 1 random write, InnoDB will perform 8 random writes. I do not have a…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… is unflushed in log buffer as well as when last checkpoint was performed. Innodb uses fuzzy checkpointing so this line hold log sequence, all… 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…
Post: How to estimate time it takes Innodb to Recover ?
May 9, 2007 By 7 Comments
… frequently in Innodb talks and during consulting engagements. It is well known to get better performance you should normally set innodb_log_file_size large. We however usually recommend caution as it may significantly increase recovery time if Innodb needs…
Post: Choosing proper innodb_log_file_size
July 3, 2006 By 12 Comments
…’re doing significant amount of writes to Innodb tables decent size of innodb_log_file_size is important for MySQL Performance. However setting it too large will… on recovery and why large innodb_log_file_size slows down recovery. During startup after crash Innodb scans log files to find log records which only have been…
