April 16, 2014

Aligning IO on a hard disk RAID – the Theory

Now that flash storage is becoming more popular, IO alignment question keeps popping up more often than it used to when all we had were rotating hard disk drives. I think the reason is very simple – when systems only had one bearing hard disk drive (HDD) as in RAID1 or one disk drive at […]

Impact of the number of idle connections in MySQL

Be careful with my findings, I appear to have compile in debug mode, I am redoing the benchmarks. Updated version here. I recently had to work with many customers having large number of connections opened in MySQL and although I told them this was not optimal, I had no solid arguments to present. More than […]

Fast storage: 8 SSD Intel X-25M 80GB benchmarks

I appreciate opportunity Jos van Dongen from Tholis Consulting gave me. He granted me access to servers with 8 attached Intel X-25M 80GB MLC cards. The cards attached to 2 Adaptec 5805 raid controllers, with 4 cards per controller. The cost of setup is 8 x 260$ (X-25M) + 2×500$ (Adaptec 5805) = ~3000$. Available […]

InnoDB, InnoDB-plugin vs XtraDB on fast storage

To continue fun with FusionIO cards, I wanted to check how MySQL / InnoDB performs here. For benchmark I took MySQL 5.1.42 with built-in InnoDB, InnoDB-plugin 1.0.6, and XtraDB 1.0.6-9 ( InnoDB with Percona patches). As benchmark engine I used tpcc-mysql with 1000 warehouses ( which gives around 90GB of data + indexes) on my […]

EC2/EBS single and RAID volumes IO benchmark

During preparation of Percona-XtraDB template to run in RightScale environment, I noticed that IO performance on EBS volume in EC2 cloud is not quite perfect. So I have spent some time benchmarking volumes. Interesting part with EBS volumes is that you see it as device in your OS, so you can easily make software RAID […]

RAID vs SSD vs FusionIO

In benchmarks passion (see my two previous posts) I managed to setup all three devices (RAID was on board; Intel X25-E SSD connected to HighPoint controller, FusionIO card) on our working horse Dell PowerEdge R900 (btw, to do that I had to switch from CentOS 5.2 to Ubuntu 8.10, as CentOS was not able to […]

Impact of logging on MySQL’s performance

Introduction When people think about Percona’s microslow patch immediately a question arises how much logging impacts on performance. When we do performance audit often we log every query to find not only slow queries. A query may take less than a second to execute, but a huge number of such queries may significantly load a […]

How Percona does a MySQL Performance Audit

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 […]

MySQL 6.0 vs 5.1 in TPC-H queries

Last week I played with queries from TPC-H benchmarks, particularly comparing MySQL 6.0.4-alpha with 5.1. MySQL 6.0 is interesting here, as there is a lot of new changes in optimizer, which should affect execution plan of TPC-H queries. In reality only two queries (from 22) have significantly better execution time (about them in next posts), […]

Testing the Group Commit Fix

As you may know, Kristian Nielsen made a fix for the Group Commit Problem which we many times wrote about. The fix came into MariaDB 5.3 and Mark Callaghan tested it recently . We ported this patch to Percona Server (it is not in the main branch yet), and here are the results of my […]