One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory than you would expect, causing swapping or other [...]
Make your file system error resilient
August 24, 2011 By 8 Comments
One of the typical problems I see setting up ext2/3/4 file system is sticking to defaults when it comes to behavior on errors. By default these filesystems are configured to Continue when error (such as IO error or meta data inconsistency) is discovered which can continue spreading corruption. This manifests itself in a worst way [...]
Disaster: LVM Performance in Snapshot Mode
February 5, 2009 By 55 Comments
In many cases I speculate how things should work based on what they do and in number of cases this lead me forming too good impression about technology and when running in completely unanticipated bug or performance bottleneck. This is exactly the case with LVM Number of customers have reported the LVM gives very high [...]
How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This [...]
Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
For a couple of months there have been no updates to our msl patch, however recently I managed some time to change this. The functionality was extended a little bit and what’s even more important the patch is available for all the recent MySQL releases. To remind anyone who has not yet come across this [...]
Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
I now got answers to the second portions of the questions you asked Heikki. If you have not seen the first part it can be found here. Same as during last time I will provide my comments for some of the answers under PZ and will use HT for original Heikkis answer. Q26: You also [...]
Heikki Tuuri Innodb answers – Part I
October 26, 2007 By 19 Comments
Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about this I decided to publish the answers I have so far. Plus we may get some interesting follow up questions [...]
How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
As you might know while running GROUP BY and some other kinds of queries MySQL needs to create temporary tables, which can be created in memory, using MEMORY storage engine or can be created on disk as MYISAM tables. Which one will be used depends on the allowed tmp_table_size and also by the data which [...]
Innodb Recovery – Is large buffer pool always better ?
July 17, 2007 By 3 Comments
How does Buffer Pool size affects Innodb Performance ? I always expected the effect to be positive, Innodb with large buffer pool to performing better. Including Recovery of course. I even blogged about it. It turns out it is not always the case. Last week I was called to help with Innodb crash recovery on [...]
PBXT benchmarks
April 8, 2007 By 14 Comments
The PBXT Storage Engine (http://www.primebase.com/xt/) is getting stable and we decided to benchmark it in different workloads. This time I tested only READ queries, similar to ones in benchmark InnoDB vs MyISAM vs Falcon (http://www.mysqlperformanceblog.com/2007/01/08/innodb-vs-myisam-vs-falcon-benchmarks-part-1) The difference is I used new sysbench with Lua scripting language, so all queries were scripted for sysbench.
