Github’s recent post-mortem is well worth reading. They had a series of interrelated failures that caused their MySQL servers to become unavailable. The money quote: The automated failover of our main production database could be described as the root cause of both of these downtime events. In each situation in which that occurred, if any member of our operations team had been asked if the failover should have been performed, the answer would have been a resounding no.

New home of the InnoDB team blog.

So the MySQL Connect Conference is just around the corner. For those of you that do not get the newsletter:

The Oracle INFORMATION INDEPTH NEWSLETTER MySQL Edition was recently sent out. Take advantage of this newsletter because it highlights the schedule nicely with links into the abstracts. It also lists the receptions, demo pods.


http://www.oracle.com/us/corporate/newsletter/samples/mysql-1384701.html

Every now and then you’ll have no choice but to restart the mysql server, whether it be for editing server variables, upgrading, etc.. When the server is restarted, among the operations performed, it commits all active transactions, it flushes all dirty pages (data in memory) to disk and on restart, the buffers are wiped and [...]

In 11 days I will be heading to NagiosWorld, and from there I go straight to MySQL Connect, and that is the end of September. So this week we have been focusing on wrapping up our 3rd quarter goals (and making new goals for the 4th quarter of 2012). We have also seemingly done a bunch of work on different aspects of the Bugzilla database clusters. This week, the database team has:

• Built out new Bugzilla production database cluster in a failover data center, including monitoring.
  
• Analyzed a full days’ worth of general and slow query logs for each database in the Bugzilla cluster so we can make optimization …

This week we present what Multi-Version Concurrency Control (MVCC) means, as well as how InnoDB implements it to achieve transactionality and ACID compliance. Ear candy is a GROUP BY performance gotcha, and At the Movies is a FULLTEXT webinar from Percona.

Events
MySQL Connect will be held in San Francisco on Saturday September 29th and Sunday September 30th. The schedule is now online.

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One of the MySQL servers I help manage was encountering some problems with a full data directory. It was a bit mysterious, because we couldn’t find any files to account for the increased usage. Here are some things we checked:

1. A recursive ls -l didn’t show any more, or larger, files than usual.
2. Using lsof and looking at the SIZE column didn’t either.
3. There were not enough temporary files or tables open (as shown by lsof) to account for the disk space.

Oddly, someone discovered that FLUSH TABLES would drop disk usage by about 15GB in a fraction of a second, allowing the server to continue running without problems.

I carefully measured all of the items in the above list before and after FLUSH TABLES. No doubt about it: no files went away, no files shrank, yet df and du showed the difference in the space free and …

Software patents have been an agent of change in open source over the last decade, as I explained in my keynote at the 8th International Conference on Open Source Systems this week. Most notably, the astonishing proliferation of software patents has forced technology companies to spend a lot of time and energy assembling defensive portfolios.

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Taxonomy upgrade extras: monitoringgaleraplugincluster

Based on customer feedback we have decided to add a plugin Galera Cluster for MySQL to our MySQL Nagios/Icinga Plugins.

The module checks, if the node is in status Primary and if the expected amount of Galera Cluster nodes is available. If not, a warning or an alarm is returned.

The script is written in Perl and is Nagios Plugin API v3.0 …

With the summer approaching in Australia and Winter making inroads in Canada, the contrasts are also vivid in the blog posts of Oracle, SQL Server and MySQL. Relishing this distinguished medley, Log Buffer Edition is blossoming with new blog posts in Log Buffer #286. Oracle: Julian Dontcheff throws some light on not-much discussed Bloom Filters. [...]