May 23, 2013

How expensive is USER_STATISTICS?

One of our customers asked me whether it’s safe to enable the so-called USER_STATISTICS features of Percona Server in a heavy-use production server with many tens of thousands of tables. If you’re not familiar with this feature, it creates some new INFORMATION_SCHEMA tables that add counters for activity on users, hosts, tables, indexes, and more. [...]

Announcing Percona Server 5.5.24-26.0

Percona is glad to announce the release of Percona Server 5.5.24-26.0 on June 1st, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.24, including all the bug fixes in it, Percona Server 5.5.24-26.0 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release can [...]

Estimating Replication Capacity

It is easy for MySQL replication to become bottleneck when Master server is not seriously loaded and the more cores and hard drives the get the larger the difference becomes, as long as replication remains single thread process. At the same time it is a lot easier to optimize your system when your replication runs [...]

check-unused-keys: A tool to interact with INDEX_STATISTICS

With the growing adoption of Google’s User Statistics Patch**, the need for supporting scripts has become clear. To that end, we’ve created check-unused-keys, a Perl script to provide a nicer interface than directly querying the INFORMATION_SCHEMA database.

Three ways to know when a MySQL slave is about to start lagging

The trouble with slave lag is that you often can’t see it coming. Especially if the slave’s load is pretty uniform, a slave that’s at 90% of its capacity to keep up with the master can be indistinguishable from one that’s at 5% of its capacity. So how can you tell when your slave is [...]

Google’s user_statistics V2 port and changes

Recently Google published V2 release of patches, one of them user_statistics we use in our releases. New features are quite interesting so we decided to port it to fresh releases of MySQL. Features includes: New statistics per user (Cpu_time, Bytes_received, Bytes_sent, etc) New command SHOW CLIENT_STATISTICS, which shows statistics per client’s hostname, not per user [...]

New patches, new builds

We made new patches, improved previous and want to announce new builds for 5.0.62, 5.0.67 and 5.1.26 versions. One of biggest changes we separated releases of 5.0 into two branches. First, just “-percona” release is more stable and contains only stable and proven on many installation patches. Second is “-percona-highperf” release, which contains experimental patches [...]

Userstats patches with information schema support

Recently, we added information schema support to Google’s userstats patch. There are three information schema tables added: user_statistics, table_statistics, index_statistics. One can now use select * from information_schema.user_statistics along with show user_statistics. Links: Patch for 5.0.62 Patch for 5.1.26

MySQL extensions for hosting

A few weeks ago I was asked to isolate some functionalities from Mark Callaghan’s MySQL patch bundle. They were extensions adding per-user and per-table accounting to the database, accessible with a new set of commands such as SHOW TABLE_STATISTICS, SHOW INDEX_STATISTICS and SHOW USER_STATISTICS. The first two can interest anyone to periodically check what data [...]