… software RAID 10. Now let’s come to the MySQL configuration. MySQL Configuration I used Percona Server 5.5.22-55 for…_io_threads = 4 innodb_file_per_table = 1 ## Disabling query cache query_cache_size = 0 query_cache_type = 0 You can see that the… log flushing, which can cause downward spikes in performance. Other then that, I have also disabled query cache to avoid contention caused by query…
Post: InnoDB's gap locks
March 27, 2012 By 14 Comments
…, 3 row lock(s), undo log entries 1 MySQL thread id 3, OS thread handle 0x7f84a78ba700, query id 163 localhost msandbox TABLE LOCK… your transactions affecting the concurrency and the performance you can disable them in two different ways: 1- Change the ISOLATION level… that from happening. 2- innodb_locks_unsafe_for_binlog = 1. Disables the gap locks except for foreign-key constraint checking or…
Post: MySQL Slow query log in the table
May 31, 2007 By Leave a Comment
As of MySQL 5.1 get MySQL slow query log logged in mysql.slow_log table instead of the file as you had in previous …’ve got some time to play with table based slow query log in production while tuning one of the systems. It is… if I convert table to MyISAM, disable concurrent inserts and run long reporting query on the log file query execution is still proceeds. I…
Post: Enabling/Disabling query log without server restart in MySQL 5.0
September 13, 2007 By 13 Comments
… do in MySQL 5.0 and below ? Use Our Patch – With this patch you can get all queries logged as slow queries (with times) and as you can change long-query-time online you can effectively enable and disable debug logging live. Note however this is not 100% equivalent for general query log – for example connects or queries with syntax…
Post: Does Slow query log logs all slow queries ?
June 25, 2007 By 2 Comments
…use MySQL Slow query log to log all slow queries to catch problematic queries or for audit purposes. In fact however not all the queries are logged. I… slow query logging had to be disabled for such queries. What does it mean ? Simply what you can’t really trust standard slow query log – some queries…
Post: Poor man's query logging
November 7, 2008 By 5 Comments
…is slow log enabled by –log-slow-queries parameter (MySQL 5.1 requires also –slow-query-log), which was designed to store poorly performing queries that … restart to disable it when no longer necessary (though actually slow log can be disabled by simply setting long_query_time MySQL variable …
Post: Managing Slave Lag with MySQL Replication
October 12, 2007 By 11 Comments
…setup do not forget to disable binary logging with SET SQL_BIN_LOG=0 before you run ALTER TABLE query. Replication Overload Many … Unfortunately MySQL Slow Query Log does not log replication queries. Though this is one of few slow query logging improvements you can get with our Slow Query Log patch…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
…query-digest to compare workloads on servers. Best if you can analyze full query logs…query which performs differently between MySQL Server versions you should: Check Query Plan Run EXPLAIN to see if plans for the query…update the stats. You may consider disabling innodb_stats_on_metadata and …
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
… I spotted the query pattern responsible for large portion of the load in the application by aggregating query log with mk-query-digest. When I filtered out only queries of this pattern and got a…,mysql_execute_command,mysql_parse,dispatch_command,do_command,do_handle_one_connection,handle_one_conne ction,start_thread,clone P.S Disabling…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
… which makes it better to disable them. The MySQL Settings are probably what is the most interesting: MySQL 5.0 Tuning in /etc…_heap_table_size=200M log-output = FILE log-slow-queries=/tmp/mysql-slow.log long_query_time = 1 innodb_data_home_dir = /data/mysql/var innodb_data… is interesting though slow query log remained enabled – probably it caused so little overhead because there were no slow queries it just was…
