…log_file_size is important for MySQL Performance. However setting it too large will increase recovery time, so in case of MySQL…log_file_size slows down recovery. During startup after crash Innodb scans log files to find log…”undo” phase is size your transactions appropriately – so updates/inserts/…
Post: ACTIVE with Locks – Now thats a problem !
June 2, 2011 By 2 Comments
…log entries 2 In this case we see transactions are holding some locks and perform some update/deletes as there are undo log…transaction and so you can get system to slow down because of maintaining many old row versions. I would prefer not to see transactions…
Post: MySQL Crash Recovery
July 30, 2006 By 26 Comments
… simply power can go down which all mean similar things – MySQL Shutdown is unexpected and there…at onces, which typically make system extremely slow and also can use up all allowed…transactions but it is it. It is Performance of this process which may cause the problems. As I already wrote innodb_log…
Post: Fighting MySQL Replication Lag
September 22, 2008 By 6 Comments
…MySQL binary log can’t proceed. It is either more than than just about queries – if you’re using explicit transactions…LIKE “%cheap rolex%”; This query will perform full table scan in MySQL 5.0 (even if there are…cases is to simply space it out and slow down your batch job (such as adding sleep calls)…
Post: MySQL Server Memory Usage
May 17, 2006 By 18 Comments
…MySQL Server so it uses too small amount of memory it will likey perform… or make operation to swap seriously slowing down. On now legacy 32bit platforms … innodb_additional_memory_pool_size, innodb_log_buffer_size, query_cache_size…. stack, net buffer etc. If transaction is started some more space can…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… for data mining stock market transactions,” or whatever the case may…be a really major effort chasing down something like a bug in …full explanation in our book, High Performance MySQL 2nd Edition (it’s not … microsecond logging and additional information in the slow query log output. The stock MySQL …
Post: How much overhead DRDB could cause ?
June 2, 2008 By 4 Comments
…log writes, which is critical and latency sensitive. What many people do not realize is MySQL has to deal with multiple logs and perform…MySQL 5.0 – there is event written to the binary log to “prepare” XA transaction, when there is record in Innodb log…. This means DRBD slow down things 3 times+ …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…performance counters, statistics, information about transaction processing and all kinds of other things. In MySQL 5 number of Innodb performance… OS Waits are relatively slow, and if you get…purposes only. — LOG — Log sequence number 84 3000620880 Log flushed …you can tune it down. Even if free …
Post: MySQL extensions for hosting
April 24, 2008 By 11 Comments
…bring the server down. You can have slow query log enabled and review…254 Other_commands: 85 Commit_transactions: 0 Rollback_transactions: 0 mysql> SHOW TABLE_STATISTICS LIKE ‘hosting2%’; …Other_commands a few MySQL performance counters broken down by users (full joins, …
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
…which slows down throughput. If we could control the checkpointing rate we could use an 8G write ahead log…good performance is to set innodb_flush_log_at_trx_commit=2, that is, to flush the log …MySQL‘s binlog and InnoDB’s log must have the transactions in the same order, for a recovery based on MySQL…
