I had a customer recently who needed to reduce their database size on disk quickly without a lot of messy schema redesign and application recoding. They didn’t want to drop any actual data, and their index usage was fairly high, so we decided to look for unused indexes that could be removed. Collecting data It’s [...]
Review of MySQL 5.6 Defaults Changes
October 8, 2012 By 10 Comments
James Day just posted the great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot of good changes and many defaults are now computed instead of hardcoded. Though some of changes are rather puzzling for me. Lets go over them: back_log = 50 + ( max_connections / [...]
White Paper: Flashcache and MySQL on Virident drive
September 19, 2011 By 2 Comments
Our latest MySQL white paper is Improving Percona Server performance with Flashcache on the Virident tachIOn Drive. (Virident funded the research, but as always, we wrote the report ourselves.) The conclusion is that Flashcache can be good for read-heavy workloads, but more research is needed to understand its performance characteristics on write-heavy workloads. We explain [...]
MySQL Connection Timeouts
April 19, 2011 By 4 Comments
Sometimes on very busy MySQL server you will see sporadic connection timeouts, such as Can’t connect to MySQL server on ‘mydb’ (110). If you have connects timed in your application you will see some successful connections taking well over the second. The problem may start very slow and be almost invisible for long time, for [...]
Choosing proper innodb_log_file_size
July 3, 2006 By 12 Comments
If you’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 increase recovery time, so in case of MySQL crash or power failure it may take long time before MySQL Server is operational again. So how to find the optimal combination [...]
MySQL Sizing questions
June 23, 2006 By 4 Comments
I frequently get questions along the lines of “how many transactions per second MySQL can do” or “how many servers I need to handle 100.000 users” or “which hardware would be enough to handle my 40GB” database. There are two things which are very interesting about these questions which make them funny and annoying at [...]
