… very frequent cases with performance problems with MySQL is what they happen every so often or certain times. Investigating them we find out… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing…
Post: MySQL Slow query log in the table
May 31, 2007 By Leave a Comment
… in MySQL is well though of in regards to avoiding trouble. For example you can’t ALTER log table while query is running…” query by removing comments and replacing constants with some placeholders as this would allow to aggregate log entirely in SQL finding most frequent slow query types or queries which load server the most. The other handly feature would be…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…queries themselves. If the client has long-running queries, it can be pretty easy to catch. Maybe they’re long-running…mysql.* tables, running mk-duplicate-key-checker to find…most expensive queries, in total execution time. By the way, the slow query logs in the stock MySQL… we can frequently help …
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 6 Comments
…. Digging deeper we would find some change, though often…MySQL Restart MySQL Restarts may include recovery time but what is the most…) are frequent cause of concern. Remember replication runs as a…queries mysql. I’ve seen monitoring updates which would add excessively expensive and frequent query…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
…difficult or impossible to find the right threshold for…covered in another plugin) are frequent causes of serious …mysql-replication-delay plugin checks for excessive delay, and pmp-check-mysql-replication-running…responds to a query. The pmp-check-mysql-status …cover some of the most common and severe …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…MySQL 5 number of Innodb performance counters were exported and now available in SHOW STATUS output. Most… frequently slots are allocated in it and how frequently threads… to find truly conflicting statements. For most simple … originated from query executions are executed by threads running queries. …
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
…most accurate approach but it does not work in Oracle MySQL Server. set userstat_running=1 and run following query: mysql…need to adjust regular expression for finding users replication thread uses. 3) …if it processes query or simply waiting. By pooling processlist frequently (for example 10 …
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
…MySQL manual doesn’t fall into this trap, but if you search Google for Key_read_requests, you will find…user desires by running silly queries that do … what I called “mostly factual” above, …MySQL to guide your decisions. It is also not the be-all and end-all of MySQL performance, and people frequently…
Post: Estimating Undo Space needed for LVM Snapshot
June 9, 2008 By 5 Comments
… properly to be usable for MySQL Backups. Quite frequently I find LVM installed on the… you know the IO pattern, say most of traffic comes from batch updates…you better to use your experience – run the backup and see how snapshot…, I mean binary logs, slow query log, general query log etc, if they get …
Post: MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
Running EXPLAIN for problematic queries is very powerful tool for MySQL …MySQL will execute these subselects on explain to provide plan for top most … is more complicated It is frequent approach to take number of… want to find more information about understanding EXPLAIN output, MySQL manual EXPLAIN…
