With Performance Schema improvements in MySQL 5.6 I think we’re in the good shape with insight on what is causing performance bottlenecks as well as where CPU resources are spent. (Performance Schema does not accounts CPU usage directly but it is something which can be relatively easily derived from wait and stage information). Where we’re [...]
Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
During the design period of a new cluster, it is always advised to have at least 3 nodes (this is the case with PXC but it’s also the same with PRM). But why and what are the risks ? The goal of having more than 2 nodes, in fact an odd number is recommended in [...]
Percona XtraDB Cluster reference architecture with HaProxy
June 20, 2012 By 63 Comments
This post is a step-by-step guide to set up Percona XtraDB Cluster (PXC) in a virtualized test sandbox. I used Amazon EC2 micro instances, but the content here is applicable for any kind of virtualization technology (for example VirtualBox). The goal is to give step by step instructions, so the setup process is understandable and [...]
Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
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 [...]
Looking for RAID Controller without Battery Learning problems ?
January 5, 2012 By 11 Comments
A lot have been written about Battery Learning Cycle problems and its impact to MySQL Performance. Here are couple of links (1,2). It is good to see though there are some controllers coming out which solve this problem, namely Adaptec 5Z series controllers (Z stands for Zero Maintenance). This is not quite new technology they [...]
Percona Replication Manager, a solution for MySQL high availability with replication using Pacemaker
November 29, 2011 By 102 Comments
The content of this article is outdated, look here for more up to date information. Over the last year, the frustration of many of us at Percona regarding issues with MMM has grown to a level where we started looking at other ways of achieving higher availability using MySQL replication. One of the weakness of [...]
More on dangers of the caches
September 23, 2010 By 5 Comments
I wrote couple of weeks ago on dangers of bad cache design. Today I’ve been troubleshooting the production down case which had fair amount of issues related to how cache was used. The deal was as following. The update to the codebase was performed and it caused performance issues, so it was rolled back but [...]
Too many connections? No problem!
March 23, 2010 By 28 Comments
Did that ever happen to you in production?
1 2 | [percona@sandbox msb_5_0_87]$ ./use ERROR 1040 (00000): Too many connections |
Just happened to one of our customers. Want to know what we did?
How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
I vaguely recall a couple of blog posts recently asking something like “what’s the formula to compute mysqld’s worst-case maximum memory usage?” Various formulas are in wide use, but none of them is fully correct. Here’s why: you can’t write an equation for it.
5.0.75-build12 Percona binaries
January 23, 2009 By 18 Comments
After several important fixes to our patches we made binaries for build12. Fixes include: Control of InnoDB insert buffer to address problems Peter mentioned http://www.mysqlperformanceblog.com/2009/01/13/some-little-known-facts-about-innodb-insert-buffer/, also check Bug 41811 to see symptoms of problem with Insert buffer. http://www.percona.com/docs/wiki/patches:innodb_io_patches * innodb_flush_neighbor_pages (default 1) – When the dirty page are flushed (written to datafile), this parameter determines [...]
