May 22, 2013

Knowing what pt-online-schema-change will do

pt-online-schema-change is simple to use, but internally it is complex.  Baron’s webinar about pt-online-schema-change hinted at several of the tool’s complexities.  Consequently, users often want to know before making changes what pt-online-schema-change will do when it runs.  The tool has two options to help answer this question: –dry-run and –print. When ran with –dry-run and –print, pt-online-schema-change changes nothing [...]

Percona Live London 2012 talks you do not want to miss

Percona Live, London 2012 continues streak of “not to be missed” events in London, following the footsteps of Royal Wedding, Diamond Jubilee and Summer Olympics. We have prepared great set of Tutorials and Sessions for these two day event. Here is my personal selection of the talks I’d love to attend, though I rarely have [...]

Using pt-table-checksum with Percona XtraDB Cluster

As of Percona Toolkit v2.1.5, pt-table-checksum works correctly with Percona XtraDB Cluster, but it doesn’t work quite like a traditional replication setup because cluster nodes are not like traditional replicas.  In this post I demonstrate how to use pt-table-checksum with Percona XtraDB Cluster. First, you’ll need Percona Toolkit v2.1.5 or newer and Percona XtraDB Cluster 5.5.27-23.6 [...]

Released: Percona Toolkit 2.1.5

Although Percona Toolkit 2.1.4 was recently released, we soon after found and fixed a couple of bugs concerning how pt-table-checksum works with Percona XtraDB Cluster: pt-table-checksum 2.1.4 doesn’t detect diffs on Percona XtraDB Cluster nodes pt-table-checksum 2.1.4 miscategorizes Percona XtraDB Cluster-based slaves as cluster nodes There was also a bug affecting pt-table-sync –version-check, and the [...]

Tools and Techniques for Index Design Webinar Questions Followup

I presented a webinar this week to give an overview of Tools and Techniques for Index Design. Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. I’d like to invite folks who are interested in tools for query optimization to attend the new Percona [...]

Upcoming Webinar on Index Design

The proper tools and techniques for designing indexes in MySQL is a broad subject, which causes grief for many developers and database administrators. I’ll present a webinar Tools and Techniques for Index Design on October 3, 2012 at 10:00am Pacific time to give an overview of the best practices and procedures for you to build index [...]

Logging Foreign Key errors

In the last blog post I wrote about how to log deadlock errors using Percona Toolkit. Foreign key errors have the same problems. InnoDB only logs the last error in the output of SHOW ENGINE INNODB STATUS, so we need another similar tool in order to have historical data. pt-fk-error-logger This is a tool very [...]

Percona Toolkit version 2.1.4 released

The Percona Toolkit team is happy to announce the release of Percona Toolkit version 2.1.4. This is the fourth stable release in the 2.1 series, and primarily a bug-fix release; We suggest that users upgrade to the latest version of the tools. The complete list of changes is on the Launchpad milestone for 2.1.4, but [...]

Timezone and pt-table-checksum

I recently worked through an issue with a client trying to detect data drift across some servers that were located in different timezones.  Unfortunately, several of the tables had timestamp fields and were set to a default value of CURRENT_TIMESTAMP.  From the manual, here is how MySQL handles timezone locality with timestamp fields: Values for TIMESTAMP columns are [...]

Logging Deadlock errors

The principal source of information for InnoDB diagnostics is the output of SHOW ENGINE INNODB STATUS but there are some sections that are not very useful. For example, LATEST DETECTED DEADLOCK only shows, as the name implies, the latest error detected. If you have 100 deadlocks per minute you will be able to see only [...]