One of our Percona Support customers recently reported that Percona XtraBackup failed with a page corruption error on an InnoDB table. The customer thought it was a problem or bug in the Percona XtraBackup tool. After investigation we found that an InnoDB page was actually corrupted and a Percona XtraBackup tool caught the error as expected and hence the backup job failed.

I thought this would be an interesting topic and worthy of a blog post. In this article I will describe the innochecksum tool, when and how to use it and what are the possible fixes if an InnoDB table suffers from …

Facebook, the undisputed king of online social networks, has 1.23 billion monthly active users collectively contributing to an ocean of data-intensive tasks – making the company one of the world’s top MySQL users.

A small army of Facebook MySQL experts will be converging on Santa Clara, Calif. next week where several of them are leading sessions at the Percona Live MySQL Conference and Expo. I had the chance to chat virtually with four of them about their sessions: Steaphan Greene, Evan Elias, …

A few weeks ago I wrote about “MySQL Performance at High Concurrency” and why it is important, which was followed up by Vadim’s post on ThreadPool in Percona Server providing some great illustration on the topic. This time I want to target an opposite question: why MySQL performance at low concurrency is important for you.

I decided to write about this topic as a number of recent blog posts and articles look at MySQL performance starting with certain concurrency as the low point. For example, …

InnoDB’s checkpoint algorithm is not well documented. It is too complex to explain in even a long blog post, because to understand checkpoints, you need to understand a lot of other things that InnoDB does. I hope that explaining how InnoDB does checkpoints in high-level terms, with simplifications, will be helpful. A lot of the simplifications are because I do not want to explain the complexities of how the simple rules can be tweaked for optimization purposes, while not violating the ACID guarantees they enforce.

A bit of background: Gray and Reuter’s classic text on transaction processing introduced two types of checkpoints beginning on page 605. There is a sharp checkpoint, and there is a fuzzy checkpoint.

A sharp checkpoint is accomplished by flushing all modified pages for committed transactions to disk, and …

Mark Callaghan has graciously accepted to be the closing keynote speaker for Percona Live: San Francisco!

Mark is best known for his work behind MySQL @ Facebook, where he and his team maintain one of the largest MySQL installations around.  They also contribute back to the community with a publicly available branch of enhancements, improved diagnostic tools, and bug reports which help make MySQL better.

Mark’s keynote will be on “High-value Transaction Processing”.  I assure you, this is a presentation not to be missed.

The MySQL team at Oracle has been very busy! Tomorrow, Sept. 19th, we welcome the MySQL users and community to Oracle OpenWorld - this will be a first. We all are very excited and have been working hard to make this worth your while.

Details on MySQL Sunday

Day and Date: Sunday, Sept. 19, 2010

Time: 12:30 pm onwards (registration is prior to 12:30 and will be at Moscone location)

Location: Marriott Marquis, San Francisco

Check out the MySQL Sunday agenda.

Don't miss the opening keynote by Edward Screven, closing keynote by Marten Mickos and sessions delivered by your favorite community presenters including Mark Callaghan, Sheeri Cabral, Ronald Bradford and many more.

 Hope to see you tomorrow! …

I like to write tools that make hard things easy, when possible. By and large, MySQL is easy and simple. But some simple things are too hard with MySQL. I want to change that, at least for the things that matter the most to me, and which I think I know how to fix.

I will probably write a lot about this. I have already written a number of rants blog posts about the lack of instrumentation in MySQL, and that is where I’ll probably continue to put most of my energy.

To begin with, imagine this simple scenario. You are a remote DBA. Your client says “New Relic is showing periods of slow response time from the database.” You connect to MySQL at the command line and try to troubleshoot. How do you catch the problem in action, from within the database itself? The following are no good:

• It doesn’t count to see the problem two minutes later by observing the application tier, as New Relic does. That’s too late, and …

Eben Moglen says EC case against Oracle-Sun is flawed. The value of open source. And more.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca
“Tracking the open source news wires, so you don’t have to.”

For the latest on Oracle’s acquisition of MySQL via Sun, see Everything you always wanted to know about MySQL but were afraid to ask

# Eben Moglen told the EC he does not see threat to competition from Oracle-Sun, says EC’s objections are flawed. A statement from the SFLC is …

This is really cool. Rackspace is hiring people to work on Drizzle full-time for their cloud product, Mosso. Adrian Otto writes the Drizzle mailing list:

I was speaking with Eric Day at the developer conference, and I mentioned that Rackspace is wiling to employ full time developers for the specific purpose of furthering the Drizzle project’s mission. He suggested that I email you on this list becuase he expected there would be interest in this offer. If you work on the project now part time, and want to make it a full time job working exclusively on the Drizzle project, let me know. The Rackspcae Cloud believes …

At today's keynote by Mark Callaghan one of the new options he talked about are table change logs. He mentioned they might be of use to external applications, like Flexviews, which he mentioned but not directly. He asked if the guy who wrote it was in the audience, so I got to wave my hand and yell 'Flexviews!'.

I caught up with Mark at the Facebook party this evening. I had a chance to talk to him not only about the change logs, but also about Kickfire and the SQL chip. He asked me what I thought about working at Kickfire and I smiled and said I love it. I think I said "I've never been able to join a billion row table to a hundred million row table, sort, group and get results back in less than a minute" and I'm sure the smile never left my face.

As far as the table change logs, he verified:

• 
  
• The global transaction id will be stored in the table
  
• OLD and NEW …