Let us talk few more about disks. You might have read my previous post and Matt’s Reply and it looks like there are few more things to clarify and explain. Before I get to main topic of the article lets comment on IO vs Disk question. If you look at Disk Based databases all data [...]
MySQL Performance on Memory Appliance
March 31, 2008 By 23 Comments
Recently I have had a chance to check out MySQL Performance on “Memory Appliance” by Violin Memory which can be used as extremely high speed storage system. I helped Violin Memory to optimize MySQL for customer workload and Violin memory and also had a chance to do some benchmarks on my own. 2*Quad Core Xeon [...]
Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
I’m often asked how one can evaluate IO subsystem (Hard drive RAID or SAN) performance for MySQL needs so I’ve decided to write some simple steps you can take to get a good feeling about it, it is not perfect but usually can tell you quite a lot of what you should expect from the [...]
How Innodb flushes data to the disk ?
July 18, 2007 By 3 Comments
In my previous post I was a bit wrong giving Innodb some properties it does not have. In fact Innodb does not currently sort pages in their position order flushing them to disk. Pages to be flushed are instead identified by other means – LRU and pages which contain oldest LSN (so which were flushed [...]
Can Innodb Read-Ahead reduce read performance ?
June 26, 2007 By 2 Comments
I ran into pretty interesting behavior today. We needed to dump and reload large database and we had pretty good IO subsystem so we started number of mysqldump processes in parallel. Unlike in other case when we did load in parallel, dump in parallel did not increase IO rate significantly and we could still see [...]
RAID and Scale Out Discussions
June 12, 2007 By 3 Comments
Just found this wonderful summary of articles by Jeremy and wanted to give some of my thoughts on the topic. First lets speak about death of the RAID. I think this is far from the case especially if you consider Software RAID here. For many workloads you would like to get RAID just for the [...]
MySQL MyISAM Active Active Clustering – looking for trouble ?
March 15, 2007 By 4 Comments
Reading last few days worth of planet MySQL and commenting on some entries as you can see. The post by Oli catches my attention. There is also PDF with more details available Oli is saying you can use MySQL with Active Active Clustering and MyISAM tables if you follow certain rules like enabling external locking, [...]
SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
Many people asked me to publish a walk through SHOW INNODB STATUS output, showing what you can learn from SHOW INNODB STATUS output and how to use this info to improve MySQL Performance. To start with basics SHOW INNODB STATUS is command which prints out a lot of internal Innodb performance counters, statistics, information about [...]
Innodb Fuzzy checkpointing woes
May 10, 2006 By Leave a Comment
As you might know Innodb storage engines uses Fuzzy Checkpointing technique as part of it recovery strategy. It is very nice approach which means database never needs to “stall” to perform total modified pages flush but instead flushing of dirty pages happens gradually in small chunks so database load is very even. This works great [...]
