MySQL Performance Blog

We have been using tpcc-mysql benchmark for long time, and there many results published in our blog, but that's just single workload. That's why we are looking into different benchmarks, and one
of them is TPCE. Yasufumi made some efforts to make TPCE working with MySQL, and we are making it available for public consideration.

You can download it from our Lauchpad Percona-tools project, it's
bzr branch lp:~percona-dev/perconatools/tpcemysql

Important DISCLAIMER:
Using this package you should agree with TPC-E License Agreement,
which in human words is:

• You can't name results as "TPC Benchmark Results"
• You can't compare results with results published on http://www.tpc.org/ and you can't pretend the results are compatible with published by TPC.

And we are not going to do anything from that, your primary goals is XtraDB/InnoDB performance research and/or compare with available Storage Engines for MySQL.

The workload in tpce is quite different from tpcc. Tpcc is write intensive, while tpce
is read oriented.
To give more details, there is stats for 10 seconds:

The result is quite chatty,

but it allows you to see count of 11 different transactions per 10 secs and 90% response time.

and final result

where you can see count of successful TR (TradeResult) transactions, and
the summary result in TpsE (transactions per seconds).

Expect our results soon!

I've seen my posts on Ontime Air traffic and Star Schema Benchmark got a lot of interest
(links:

• http://www.mysqlperformanceblog.com/2010/01/07/star-schema-bechmark-infobright-infinidb-and-luciddb/
• http://www.mysqlperformanceblog.com/2009/10/02/analyzing-air-traffic-performance-with-infobright-and-monetdb/
• http://www.mysqlperformanceblog.com/2009/10/26/air-traffic-queries-in-luciddb/
• http://www.mysqlperformanceblog.com/2009/11/02/air-traffic-queries-in-infinidb-early-alpha/

).
However benchmarks by itself did not cover all cases I would want, so I was thinking about better scenario. The biggest problem is to get real big enough dataset, and I thank to Bradley C. Kuszmaul, he pointed me on Wikipedia statistics on access to Wikipedia pages, and thank to Domas, who made stats accessible. Link to the archives: http://dammit.lt/wikistats/archive/ or the original Domas's announcement .

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Percona is hiring. As part of our growth process, we introduced the role of the Shift Support Captain in 2009
(see the original announcement here) to
provide customers with a 24x7 technical contact person.

The Shift Support Team dispatches incoming emergencies, assigns new issues, handles or escalates incoming Nagios alerts from some customers, and in general makes sure things get handled
and customers get the attention they need.

You must be detail oriented, service oriented, tech savvy and as all Percona staff, able to work from home with little supervision. This is a growth position, so we're also looking for people who can become
consultants with time.

The basic requirements are:

• Excellent written and spoken English.
• Knowledge of MySQL and InnoDB.
• Knowledge of Linux systems administration.
• Knowledge of popular LAMP technologies such as Apache.
• General programming and scripting abilities.
• Proven success working in a distributed environment where
  e-mail, IRC and voice calls are the only interaction with
  clients, colleagues and managers on a daily basis.

Work is scheduled in 8-hour shifts, and some weekend shifts will be required.

Some of the benefits of working for Percona include good pay and benefits, working from home, with a team of experts who work on challenging projects everyday and who develop/contribute to many cool projects

Some travel is required, at least for a yearly company meeting, and for some conferences and other events.

If you think you're a good candidate, please fill out the contact form on our website. Thanks!

February and March as busy months for Community events.  There's MySQL University, Fosdem, the Seattle MySQL Meetup & Confoo.ca. [read more...]

A while back Friendfeed posted a blog post explaining how they changed from storing data in MySQL columns to serializing data and just storing it inside TEXT/BLOB columns. It seems that since then, the technique has gotten more popular with Ruby gems now around to do this for you automatically. [read more...]

We recently released XtraDB-9, and while we did not highlight it in announcement, the release-making feature is ability to save and restore InnoDB buffer pool.
The idea is not new and was originally developed by Jeremy Cole (sorry, I do not have the link on hands) some time ago, and now we implemented it in XtraDB.

Why would we need to save and restore content of buffer pool ?
There are several reasons.
First, it's not rate on modern servers to have 32GB+ of RAM, with allocated InnoDB buffer_pool 26GB or more. When you do restart of server, it may take long time to populate cache with useful data before you can bring it back to serve production load. It's not rare to see
maintenance cycle takes two or more hours, mainly because the slave need to catchup with master and to warm cache.
In case with the server crash, it is even worse, you need to wait possible long time on InnoDB
recovery (we have the patch for that too, in that post you can see InnoDB recovery took 1h to accomplish) and after that warm caches.

Second, it is useful for some HA schemas, like DRBD, when, in case of failover, you need to start passive instance on cold.

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So you get MySQL or other applications using too much memory on the box or OS behaving funny and using more memory for cache and pushing application to the swap. This causes swapping and causes performance problems. This much is obvious. But how bad is it ? Should you count it same as normal Disk IO as the box is having or is it worse than that ?
[read more...]

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) + 2x500$ (Adaptec 5805) = ~3000$.
Available space varies in depends on raid setup from 300GB to 600GB.

The logical comparison is to compare results with FusionIO 320GB MLC card, so I will copy results from FusionIO 320GB MLC benchmarks.

[read more...]

I generally thought about MySQL replication as being quite low overhead on Master, depending on number of Slaves. What kind of load extra Slave causes ? Well it just gets a copy of binary log streamed to it. All slaves typically get few last events in binary log so it is in cash. In most cases having some 10 slaves are relatively low overhead not impacting master performance a lot. I however ran into the case when performance was significantly impacted by going from 2 to 4 slave on the box. Why ?
[read more...]

After a nice long vacation, it's time to unveil our destinations for public classes in 2010.  We are now offering a course for Developers as well as DBAs.  The dates are:

• Seattle 16 February
• San Francisco 18-19 February
• Boston 22-23 February
• New York City 25-26 February
• Montréal 8-9 March
• Denver 15-16 March
• Chicago 18-19 March
• Washington DC 25-26 March
• Los Angeles 19-20 April
• Raleigh 22-23 April
• Toronto 3-4 May

Do you run a meetup group in one of the cities listed? Get in touch! I would be happy to come along and give a presentation, or just answer your MySQL questions over a dinner or beer.  You can reach me via @percona or email.