We have seen number of issues with MySQL Server related to amount of memory you have in the system – these range from problems with large size Query Cache to bad drop table performance with large Innodb Buffer Pool size. As such I wonder how much memory do we really use to run MySQL Server [...]
Announcing Percona Server 5.5.28-29.1
October 26, 2012 By 1 Comment
Percona is glad to announce the release of Percona Server 5.5.28-29.1 on October 26th, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.28, including all the bug fixes in it, Percona Server 5.5.28-29.1 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release can [...]
MySQL 5.6.7-RC in tpcc-mysql benchmark
October 8, 2012 By 21 Comments
MySQL 5.6.7 RC is there, so I decided to test how it performs in tpcc-mysql workload from both performance and stability standpoints. I can’t say that my experience was totally flawless, I bumped into two bugs: MySQL 5.6.7 locks itself on CREATE INDEX MySQL 5.6.7-rc crashed under tpcc-mysql workload But at the end, is not [...]
A (prototype) lower impact slow query log
September 20, 2012 By 12 Comments
Yesterday, over at my personal blog, I blogged about the impact of the MySQL slow query log. Since we’re working on Percona Server 5.6, I did wonder if this was a good opportunity to re-examine how we could provide slow query log type functionality to our users. The slow query log code inside the MySQL [...]
How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump?
September 9, 2012 By 9 Comments
Ever ran into a situation where you saw “some important variable you really needed to know about=<optimized out>” while debugging?
Write contentions on the query cache
September 5, 2012 By 5 Comments
While doing a performance audit for a customer a few weeks ago, I tried to improve the response time of their top slow query according to pt-query-digest‘s report. This query was run very frequently and had very unstable performance: during the time data was collected, response time varied from 50µs to 1s. When I ran [...]
Announcing Percona Server 5.1.65-14.0
September 4, 2012 By Leave a Comment
Percona is glad to announce the release of Percona Server 5.1.65-14.0 on September 4th, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.65, including all the bug fixes in it, Percona Server 5.1.65-14.0 is now the current stable release in the 5.1 series. All of Percona‘s software is open-source and free, all the details of the release can [...]
Differences between READ-COMMITTED and REPEATABLE-READ transaction isolation levels
August 28, 2012 By 3 Comments
As an instructor with Percona I’m sometimes asked about the differences between the READ COMMITTED and REPEATABLE READ transaction isolation levels. There are a few differences between READ-COMMITTED and REPEATABLE-READ, and they are all related to locking.
Filling the tmp partition with persistent connections
August 6, 2012 By 14 Comments
The use of tmpfs/ramfs as /tmp partition is a common trick to improve the performance of on-disk temporary tables. Servers usually have less RAM than disk space so those kind of partitions are very limited in size and there are some cases were we can run out of space. Let’s see one example. We’re running [...]
ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
Today I was looking at the ALTER TABLE performance with fast index creation and without it with different buffer pool sizes. Results are pretty interesting. I used modified Sysbench table for these tests because original table as initially created only has index on column K which initially contains only zeros, which means index is very [...]
