I frequently encounter MySQL servers with intermittent problems that don’t happen when I’m watching the server. Gathering good diagnostic data when the problem happens is a must. Aspersa includes two utilities to make this easier.

The first is called ’stalk’. It would be called ‘watch’ but that’s already a name of a standard Unix utility. It simply watches for a condition to happen and fires off the second utility.

This second utility does most of the work. It is called ‘collect’ and by default, it gathers stats on a number of things for 30 seconds. It names these statistics according to the time it was started, and places them into a directory for analysis.

Here’s a sample of how to use the tools. In summary: get them and make them executable, then configure them; then start a screen session and run the ’stalk’ utility as root. Go do …

The May release of Maatkit included a new feature in mk-query-digest. This allows you to process queries in many pieces, write out intermediate results, and then combine the pieces in a separate step. Maybe it’s not exactly map-reduce, but it makes a good headline.

The purpose is to enable query analysis across an arbitrarily large group of servers. Process queries on all of them, ship the results to a central place, and then combine them together. Pre-processing the results has some nice benefits, such as reduced bandwidth requirements, speeding up processing by doing it in parallel, and reducing the workload on the central aggregator. One Percona customer with many MySQL instances is trying this out.

The --save-results option on mk-query-digest saves the digested results to a file, stopping just before the final stages of the query event pipeline. There is a tool in Subversion trunk, tentatively called …

A special extended edition of Tech Messages for 2010-04-15 through 2010-04-24:

• The Onion Uses Django, And Why It Matters To Us
  I love Django too.
• Open Source Network Monitoring and Systems Management - Zenoss Blog: No Node Left Behind: Datacenter Barometer: BitNami Simplifies Stacks
• mysql-cacti-templates
  Offers complete templates and a method for adding your own. Highly recommended.
• Increase maximum size of PST files
  Microsoft Outlook …

Some of the utilities we were adding to Maatkit really did not belong there. Yes, this included some of the functionality in the now-retired mk-audit tool. We really learned a lesson about what it’s possible to support, design, spec, code, and test in a single tool.

I’ve moved those tools to a new project, Aspersa. Some folks are revolting and calling it Asparagus, because apparently that’s easier to say. Aspersa is the name of the common garden snail, which turns out to be a fascinating creature. It is also slow. Draw your own conclusions.

This project is more of a home for simple scripts and snippets — a simple place I can grab all the little utilities I use to make my life easy. There is a “summary” tool that largely replaces mk-audit’s functionality outside the database, and I plan to add a …

At work we have been looking for tools to monitor MySQL and at the same time provide as much diagnosis information as possible upfront when an alarm is triggered. After looking around at different options, I decided to test MONyog from Webyog, the makers of the better known SQLyog. Before we go on, the customary disclaimer: This review reflects my own opinion and in no way represents any decision that my current employer may or may not make in regards of this product.
First ImpressionYou know what they say about the first impression, and in this where MONyog started with the right foot. Since it is an agent-less system, it only requires to install the RPM or untar the tarball in the server where you're going to run the monitor and launch the daemon to get started. How much faster or simpler can it be? But in order to start monitoring a server you need to do some …

We have an early draft of a new tool available for you to use and test. It uses heuristics to find problems in SQL. Please use it and give feedback! Here’s how:

$ wget http://www.maatkit.org/trunk/mk-query-advisor
$ perl mk-query-advisor /var/log/mysql/slow.log

By default it consumes a log file in MySQL’s slow query log format, but it can also parse the general-log format, and if you have any other kind of log you can feed it through mk-query-digest to transform the log into something it can recognize. Tell me if you’d be able to spot the mixture of join styles and use of leading % wildcards in the following query without help:

# Query ID 0x643E813A9ABDA151 at byte 2001701
# CRIT JOI.001 Mixing comma and ANSI joins.
# WARN ARG.001 Argument with leading wildcard.
SELECT `rhubarb_series_title`.`id`, `rhubarb_series_title`.`series_id`, …

I've been working in a fully distributed work environment for almost 8 years now (I joined MySQL AB in April, 2002). Therefore I've been reading Toni Schneider's blog post about the "5 reasons why your company should be distributed" with great interest – he raised several points that I fully agree with and which I covered in my talks about "Working for a virtual company - how we do it at MySQL" at last year's next09 conference (slides, video) and at …

I'm happy to announce that my talk "Making MySQL administration a breeze - a look into a MySQL DBA's toolchest" has been accepted for this year's edition of the MySQL Conference & Expo in Santa Clara, which will take place on April 12-15, 2010. The session is currently scheduled for Wednesday 14th, 10:50 in Ballroom E.

My plan is to provide an overview over the most popular utilities and applications that a MySQL DBA should be aware of to make his life easier. The focus will be on Linux/Unix applications available under opensource licenses that ease tasks related to user administration, setting up and administering replication setups, performing backups and security audits.

Of course I will cover the usual …

My proposal has been accepted, yay!

I'll be speaking on a topic that I feel passionate about: MySQL Server Diagnostics Beyond Monitoring. MySQL has limitations when it comes to monitoring and diagnosing as it has been widely documented in several blogs.

My goal is to share my experience from the last few years and, hopefully, learn from what others have done. If you have a pressing issue, feel free to comment on this blog and I'll do my best to include the case in my talk and/or post a reply if the time allows.

I will also be discussing my future plans on sarsql. I've been silent about this utility mostly because I've been implementing it actively at work. I'll post a road map shortly based on my latest experience.

I'm excited about meeting many old friends (and most now fellow MySQL alumni) …

Maatkit does more than just MySQL. I’ve just committed a new version of mk-query-digest, a powerful log analysis tool, with support for Posgtres logs, in both syslog and stderr format. I’m hoping that people will give this a spin in the real world. I have lots of test cases, but that’s never enough; I’m looking for people to crunch their logs and let me know if anything breaks.

A brief tutorial:

# Get it
$ wget http://www.maatkit.org/trunk/mk-query-digest

# Run it
$ perl mk-query-digest --type pglog /path/to/log/file

# Learn about it (search for the string "pglog")
$ perldoc mk-query-digest

I’m going to close comments on this blog post so I don’t get bug reports in the comments. If you have feedback, please post it to the Maatkit mailing list, or …