A customer opened a support issue to ask about some help determining why they were seeing a lot of Lock Wait Timeouts. I asked them to enable the InnoDB Lock Monitor so that I could get a look at what was going on in their transactions and whether there might be some locks held longer than necessary.

The customer sent in a 184MB MySQL error log with 4773836 lines. I started looking through it, but I could tell I was going to need a better way to get a better overview of the file than what I'd be able to piece together trying to poke through it and look for individual lines. I started piping the file through a variety of UNIX tools to narrow down what I was seeing.

I ended up with this mess:

 < mysqld.err grep ACTIVE | cut -d' ' -f 2,4 | sort -rn -k 2 | perl -F, -ane 'print "$F[0] $F[1]" if not $v{$F[0]}; $v{$F[0]} = $F[1];' | head

It's hideous, but it's pretty helpful. Here's the output:

1EC080F1 …

Note: this article was originally published on http://blogs.innodb.com on Dec 23, 2011 by Vasil Dimov.

Continues from Improving InnoDB memory usage.

Here are some numbers from the fixups described in the above article:

The workload consists of 10 partitioned tables, each one containing 1000 partitions. This means 10’000 InnoDB tables. We truncate the tables, then restart mysqld and run:

1. INSERT a single row into each of the 10 tables
2. SELECT * from each table
3. FLUSH TABLES (this causes the tables to be closed and reopened on the next run)
4. wait for 10 seconds

we repeat the above steps 10 …

Merry Christmas! Just in time for the holidays, we have released a new tool to help you configure and manage your MySQL servers. Our online MySQL Configuration Wizard can help you generate a good basic configuration file for a server. This MySQL tuning wizard is our answer to the commonly asked question, “what is a good default configuration file for my server with 16 GB of RAM?”

We have a raft of new features planned for future releases, including advanced configuration options, supersafe settings to prevent bad things from happening, and much more. In the future we plan to add more online tools to help you be more productive.

Please give it a spin and let us know what you think. Credit for this tool must go to Miguel Trias, our talented lead developer. Thanks also to the many experts inside Percona who helped test, and …

MySQL Connector/Net 6.5.0, a new version of the all-managed .NET driver for MySQL has been released.  This is a beta release of our newest connector and comes with several new features.  It is of beta quality and should not be used in any production environment.  It is appropriate for use with MySQL server versions 5.0-5.6

It is now available in source and binary form from here and mirror sites (note that not all mirror sites may be up to date at this point-if you can't find this version on some mirror, please try again later or choose another download site.)

This new versions brings new features such as

• Exception and command injector support
• Millseconds support
• Better partial-trust support
• Better intellisense including auto-completion when editing stored …

MySQL Connector/Net 6.5.0, a new version of the all-managed .NET driver for MySQL has been released.  This is a beta release of our newest connector and comes with several new features.  It is of beta quality and should not be used in any production environment.  It is appropriate for use with MySQL server versions 5.0-5.6

It is now available in source and binary form from here and mirror sites (note that not all mirror sites may be up to date at this point-if you can't find this version on some mirror, please try again later or choose another download site.)

This new versions brings new features such as

• Exception and command injector support
• Millseconds support
• Better partial-trust support
• Better intellisense including auto-completion when editing stored …

The MySQL part of the PHP reference manual is currently being restructured: new landing and overview page, mysqli quickstart prepared. Ten years ago, there was the mysql extension and that was it. Today, beginners are faced with three MySQL APIs/extensions, two libraries and more than three library plugins. MySQL support by PHP has never been better. But, where to start: web search for tutorials, a book? The results one gets tend to be flawed: outdated, incomplete, flawed… Thus, the update.

A landing and overview page

The MySQL documentation staging server already shows the new landing and overview page "MySQL Drivers and Plugins". Its introduction makes the PHP reference manuals "Vendor Specific Database Extensions" section less cluttered by grouping all MySQL information under this new overview page.

Under …

Continues from Improving InnoDB memory usage.

Here are some numbers from the fixups described in the above article:

The workload consists of 10 partitioned tables, each one containing 1000 partitions. This means 10’000 InnoDB tables. We truncate the tables, then restart mysqld and run:

1. INSERT a single row into each of the 10 tables
2. SELECT * from each table
3. FLUSH TABLES (this causes the tables to be closed and reopened on the next run)
4. wait for 10 seconds

we repeat the above steps 10 times. Here is the total memory consumption by mysqld with 1GB InnoDB buffer pool during the workload:

In the fixed case (green line) you can clearly see the peaks when the commands 1. – 4. are run …

A single MySQL server is a single point of failure. A single MySQL server can only be scaled vertically by increasing hardware size, which has its limits. That’s two good reasons to migrate from a single MySQL server to a cluster of MySQL servers. However, in cloudy white christmas times, few appreciate the extra work that using a cluster causes. For example, MySQL connections must be load balanced. Please, find a comparison of different load balancing architectures in the short presentation. Choose the one that’s best for you - maybe it is PECL mysqlnd_ms 1.2, the mysqlnd replication and load balancing plugin…

Load Balancing for PHP and …

using one of the two databases

• Oracle 11.2.0.3
• MaxDB 7.8.2.26 

with SAP Kernel 7.20_ext are supported on Solaris 11. The details are documented in the SAP note 1643799 (access for SAP customers only).

New Year is the time to bid farewell to the old year and welcome the coming year. It is the time to remember the golden olden blog posts. It is the time for new beginnings and new starts in life, and of course for new blog posts. Bloggers in the database arena are also enjoying [...]