Today I’ve started moving (actually copying) all information I have about MMM to the project’s wiki.

If someone is interested in adding some information there or modifying my descriptions (yes, I know about by awful English and I hope someone will fix my mistakes), ping me (contacts are here) and I’ll add you to the project members list.

Thanks all for participation and support.

Tonight I spoke at the NY MySQL Meetup. The topic “Practical Performance Tips & Tricks” was a full packed 1 hour session, with 4 x 15 minute sections on Beginner, Intermediate, Advanced and MySQL Proxy. The goal to hopefully cover content for different level of attendees. This meeting followed up the large turnout from last month’s meeting with at least 35 people. Thanks again to Logicworks for sponsoring the night and providing the beer and food, especially to adjust for the late arriving presenter.

My Slides are download able in PDF format here.

Some additional links that were discussed during the meeting for reference included.

• …

Few month ago I heard about some initial work on MySQL Proxy software by Jan Kneschke and I thought about implementing some type of MySQL Replication Aggregator based on this software. The idea was to create some piece of software which could get many replication streams, merge them and feed to some mysql slave. This software could be used for backup purposes and many other interesting things. But back then mysqlproxy distribution has been suspended (afaik, by MySQL AB because of some legal issues).

And at last, today MySQL Proxy project has been released to public and it became much more flexible so I think we need to take a look at it and try to implement such replication aggregator patches for it.

The other day I was looking for a open source, feature-rich, high performance ETL tool to use in an enterprise environment. I was disappointed nothing really seemed to match my requirements. Have I overlooked something or is this really a niche where there aren’t any viable projects? After looking in the usual places like sourceforge.net and doing a bunch of Google searches. I could not find any products that fit the bill. Here are (some of) my criteria:

• Fast. The candidate tool has to be able to move huge amounts of information between the source and target databases quickly.
• Flexible error handling. Data errors occur all the time, and when errors are encountered, we should be able to stop processing or log the error to a file or push the record into a violations table for subsequent processing. There are probably other popular strategies for handling errors, such as changing the offending data and trying to insert it …

I was playing with the 5 sample tutorial Lua scripts available here with the MySQL Proxy, but I was doing something a little inefficiently.

I started mysqld, then I started the MySQL Proxy with the lua script, then connected to MySQL via the proxy. To test a different script I was actually killing the MySQL Proxy and restarting with appropriate script, but this is unnecessary. MySQL Proxy will re-read the lua script, as specified with –proxy-lua-script on new connection. All I need to do is copy in the file in question and get a new mysql client connection.

The tech version of the right way:

$ cp tutorial-basic.lua running.lua
$ ./mysql-proxy --proxy-lua-script=running.lua &
$ mysql -uusr -p -P4040 -h127.0.0.1
mysql> # do my stuff
mysql> exit;
$ cp …

MySQL uses disk. Ok, so everybody knew that. MySQL uses disk in two primary ways.

• Random I/O (Reading & Writing Data/Index blocks)
• Sequential I/O (Binary Log, InnoDB Redo Log)

Historically it’s been best practice to separate these onto different spindles, and also separating the OS and tmp space onto a third spindle. With commodity H/W that can be easily done, but today a lot of people use SAN. Is this a good thing for a MySQL Database?
That’s a topic of much discussion at a later time, however I’ll add two points. A lot of SAN configurations are RAID 5, and RAID 10 is a better choice due to removing the requirement to calculate the parity. Second, last week I observed a RAID disk failure and it took an incredible long time for the disk to be re-built. Just how many SAN uses our there have actually timed a disk rebuild on a loaded system and seen the impact on the system in general.

…

We had the Top 5 wishes for MySQL started by Jay recently. So in true chain letter fashion I’m starting a new one this week. “The top 5 Best Practices for MySQL”. This like it’s predecessor is generally vague, so it can include points on development, design, administration etc.

My list:

1. Write your application to support Transactions (and therefore use a Transactional Storage Engine).

2. Always use SQL_MODE. e.g. at least TRADITIONAL and ANSI to ensure better data integrity and errors as errors.

3. Use the most optimal data types (particularly for number (e.g. TINY/SMALL/BIG INT and nullability) and especially in relation to columns in indexes.

4. When using InnoDB use the shortest primary key possible (e.g. INT UNSIGNED. BIGINT unless you have more then 4 billion rows in your potential data set is laziness).

5. …

If you haven’t got MySQL Proxy yet, then stop and get it now. Jan announced the release a few days ago of this new product offering from MySQL.

I first heard about MySQL Proxy at the recent MySQL Conference 2007 and actually used it a few weeks later to help address slow running queries during benchmarking with a granularity of milliseconds — Wow. The product has grown immensely since then and I’ve watched in true amazement at the speed of development by Jan, who I only found out recently was the creator of …

I was reading some points on a Blog post today here. I didn’t see it via Planet MySQL but via a Google Alert.

The post has several good beginner points on MySQL Performance, but included the point “Literal current date is better than using the CURRENT_DATE() function because literals will use the query cache but functions won?t.”

How true, I must admit I’d not considered this in reviewing code for sites that use the Query Cache heavily. Non deterministic functions invalid use of the Query Cache (Except for recent Bug #29053 which is also an interesting read. Note to self, read the new bugs more often when free time permits). Back on point.

So if you have a query like “Select the news for …

I’ve been able to steal some more time to work on my script following My ?hourly? MySQL monitor script Version 0.03 almost a month ago.

The purpose of this script is simple. Create an hourly ‘cron’ job that records and monitors information against the OS and MySQL Server. This is most helpful when environments simply don’t have any monitoring in place. I’ve found it very productive when running a benchmark on site to simply enable for an hour. An amount of analysis is required, but I at least have a baseline of data collection. That is the first goal.

So hourly.0.05.tar.gz is taking some shape, and has the following new features:

• Provide configurable flag to enable/disable OS and MySQL tests
• Added MYSQL_SID support, allowing for running MySQL tests against …