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MySQL 5.5 lock_wait_timeout: patience is a virtue, and a locked server

 | February 28, 2013 |  Posted In: Insight for DBAs, Insight for Developers, MySQL

Like Ovais said in Implications of Metadata Locking Changes in MySQL 5.5, the hot topic these days is MySQL 5.6, but there was an important metadata locking change in MySQL 5.5.  As I began to dig into the Percona Toolkit bug he reported concerning this change apropos pt-online-schema-change, I discovered something about lock_wait_timeout that shocked me.  From the […]

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CentOS 5.8 users: your UTF-8 data is in peril with Perl MySQL

 | February 22, 2013 |  Posted In: Insight for Developers, Percona Toolkit

CentOS 5.8 and earlier use Perl module DBD::mysql v3.0007 which has a bug that causes Perl not to flag UTF-8 data as being UTF-8.  Presuming that the MySQL table/column is using UTF-8, and the Perl MySQL connection is also using UTF-8, then a correct system returns: PV = 0x9573840 "\343\203\213 \303\250"\0 [UTF8 "\x{30cb} \x{e8}"] That’s a Devel::Peek inside a Perl scalar variable which […]

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Percona Toolkit 2.1.9 is ready

 | February 15, 2013 |  Posted In: Events and Announcements, Percona Software, Percona Toolkit

About a month ago, we held a bug raffle for Percona Toolkit 2.1.9.  The turnout was good and the resulting release is worth upgrading to, especially if you were affected by the backwards-incompatible changes to pt-heartbeat in 2.1.8.  Here are the release notes for Percona Toolkit 2.1.9 which highlight the bugs fixed: Percona Toolkit 2.1.9 has been released. […]

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Percona Toolkit 2.1.9 bug raffle

 | January 21, 2013 |  Posted In: Percona Software, Percona Toolkit

Since we’re very busy working on Percona Toolkit 2.2 and other projects, I thought 2.1.8 (the current latest Percona Toolkit release) would be the last release in that series, but it introduced a new bug in pt-heartbeat (despite all the tool’s tests) that I’d like to fix. A single bug fix is probably underkill for a […]

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Knowing what pt-online-schema-change will do

 | November 1, 2012 |  Posted In: Insight for DBAs, Percona Software

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 […]

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Using pt-table-checksum with Percona XtraDB Cluster

 | October 15, 2012 |  Posted In: Insight for DBAs, Percona Software, 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 […]

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Released: Percona Toolkit 2.1.5

 | October 12, 2012 |  Posted In: Events and Announcements, Percona Software, XtraDB Cluster

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 […]

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DBD::mysql 4.014 breaks pt-table-checksum 2.0

 | February 21, 2012 |  Posted In: Insight for DBAs, MySQL, Percona Software

DBD::mysql 4.014 breaks pt-table-checksum 2.0.  The cause is unknown, but the effect is a lot of errors like: DBD::mysql::st execute failed: called with 2 bind variables when 6 are needed [for Statement “…” with ParamValues: …] at ./pt-table-checksum line 7216. The fix is simple: upgrade (or even downgrade) DBD::mysql to any version except 4.014. To […]

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