If you have recently attended some Percona Live events or if you have checked some slides from Yves Trudeau, you may have heard about Percona Replication Manager (PRM), a new high availability tool for MySQL. Percona Live DC 2012 Percona Live MySQL Conference & Expo 2012 PRM is an OCF Resource Agent for Corosync [...]
How to diagnose errors in the MySQL error log
March 26, 2012 By 4 Comments
I frequently see questions about how to understand the nature of errors in MySQL’s error log. Now, there is a lot of complexity to this — the flowchart would be quite large, as with any nontrivial piece of software. But there is one particular class of errors that is relatively easy to diagnose, if you [...]
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 [...]
The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 10 Comments
This is a time-honored topic, and there’s no shortage of articles on the topic on this blog. I wanted to write a post trying to condense and clarify those posts, as it has taken me a while to really understand this relationship. Some basic facts Most of us know that writing into Innodb updates buffer [...]
Percona testing: Quick test clusters with kewpie!
January 13, 2012 By Leave a Comment
The announcement of Percona XtraDB Cluster seems to have generated a fair bit of interest : ) Although the documentation contains more formal instructions for setting up a test cluster, I wanted to share a quick way to set up an ad-hoc cluster on a single machine to help people play with this (imho) rather [...]
Setting up XFS on Hardware RAID — the simple edition
December 16, 2011 By 9 Comments
There are about a gazillion FAQs and HOWTOs out there that talk about XFS configuration, RAID IO alignment, and mount point options. I wanted to try to put some of that information together in a condensed and simplified format that will work for the majority of use cases. This is not meant to cover every [...]
Fishing with dynamite, brought to you by the randgen and dbqp
November 16, 2011 By Leave a Comment
I tend to speak highly of the random query generator as a testing tool and thought I would share a story that shows how it can really shine. At our recent dev team meeting, we spent approximately 30 minutes of hack time to produce test cases for 3 rather hard to duplicate bugs. Of course, [...]
Review of Virident FlashMAX MLC cards
November 10, 2011 By 14 Comments
I have been following Virident for a long time (e.g. http://www.mysqlperformanceblog.com/2010/06/15/virident-tachion-new-player-on-flash-pci-e-cards-market/). They have great PCIe Flash cards based on SLC NAND. I always thought that Virident needed to come up with an MLC card, and I am happy to see they have finally done so. At Virident’s request, I performed an evaluation of their MLC [...]
Recovering Linux software RAID, RAID5 Array
August 27, 2011 By 2 Comments
Dealing with MySQL you might need to deal with RAID recovery every so often. Sometimes because of client lacking the proper backup or sometimes because recovering RAID might improve recovery, for example you might get point in time recovery while backup setup only takes you to the point where last binary log was backed up. [...]
Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 13 Comments
In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we get from a proper IO alignment on a 4-disk RAID1+0 with 64k stripe element. I haven’t been running any benchmarks [...]
