April 20, 2014

Why delayed flushing can result in less work

I can think of at least two major reasons why systems delay flushing changes to durable storage: 1. So they can do the work when it’s more convenient. 2. So they can do less work in total. Let’s look at how the second property can be true.

SSD, XFS, LVM, fsync, write cache, barrier and lost transactions

We finally managed to get Intel X25-E SSD drive into our lab. I attached it to our Dell PowerEdge R900. The story making it running is worth separate mentioning – along with Intel X25-E I got HighPoint 2300 controller and CentOS 5.2 just could not start with two RAID controllers (Perc/6i and HighPoint 2300). The […]

Percona is hiring performance experts

Percona is hiring. We’ve added several experts recently and we’re growing at a fast but sustainable pace. The demand for our services is strong, and we have openings for more experts in the next couple of months. Let me explain a little about what we’re looking for at the moment. While we do have a […]

Beware: ext3 and sync-binlog do not play well together

One of our customers reported strange problem with MySQL having extremely poor performance when sync-binlog=1 is enabled, even though the system with RAID and BBU were expected to have much better performance. The problem could be repeated with SysBench as follows:

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 […]

How multiple disks can benefit for single client workload ?

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 […]

Evaluating IO subsystem performance for MySQL Needs

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 does MySQL Replication really work?

While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level. Or it’s been so long ago I can’t […]

Intel 320 SSD read performance

(this is cross-post from http://www.ssdperformanceblog.com/) While PCI-e Flash cards show great performance, I am often asked about alternatives, as price for PCI-e cards is still significant and not acceptable for small companies and startups. Intel 320 SSD appears to be a popular drive with a quite acceptable price. I wrote about write performance of these […]

Virident tachIOn: New player on Flash PCI-E cards market

(Note: The review was done as part of our consulting practice, but is totally independent and fully reflects our opinion) In my talk on MySQL Conference and Expo 2010 “An Overview of Flash Storage for Databases” I mentioned that most likely there are other players coming soon. I actually was not aware about any real […]