April 19, 2014

MySQL Error: Too many connections

We have always received quite few questions here at Percona Support on how to avoid the dreaded “Too many connections” error, as well as what is the recommended value for max_connections. So, in this article I will try to cover best possible answers to these questions so others can mitigate similar kinds of issues. My […]

Handling long-running queries in MySQL with Percona XtraBackup

I recently had a case where replication lag on a slave was caused by a backup script. First reaction was to incriminate the additional pressure on the disks, but it turned out to be more subtle: Percona XtraBackup was not able to execute FLUSH TABLES WITH READ LOCK due to a long-running query, and the […]

MySQL 5.6 Compatible Percona Toolkit 2.2 Released

A new Percona Toolkit series has been released: Percona Toolkit 2.2 for MySQL 5.6. Several months in the making and many new features, changes, and improvements make this a great new series. It replaces the 2.1 series for which we plan to do only one more bug fix release (as 2.1.10) then retire. 2.2 is […]

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

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 […]

MySQL Connection Timeouts

Sometimes on very busy MySQL server you will see sporadic connection timeouts, such as Can’t connect to MySQL server on ‘mydb’ (110). If you have connects timed in your application you will see some successful connections taking well over the second. The problem may start very slow and be almost invisible for long time, for […]

High availability for MySQL on Amazon EC2 – Part 3 – Configuring the HA resources

This post is the third of a series that started here. From the previous of this series, we now have two working EC2 instances that are EBS based. The first instance is the monitor, usually an m1.small type instance and the second instance is hamysql, a large instance type. So far, we have configured Heartbeat […]

New SpecJAppServer results at MySQL and Sun.

As you likely have seen Sun has posted the new SpecJAppServer Results More information from Tom Daly can be found here These results are quite interesting for me as I worked on some of the previous SpecJAppServer Benchmarks several years ago while being employed by MySQL. These are great results, plus they can be relevant […]

ScaleArc: Benchmarking with sysbench

ScaleArc recently hired Percona to perform various tests on its database traffic management product. This post is the outcome of the benchmarks carried out by Uday Sawant (ScaleArc) and myself. You can also download the report directly as a PDF here. The goal of these benchmarks is to identify the potential overhead of the ScaleArc […]

Percona Server 5.6.13-61.0 first GA release is now available

Percona is glad to announce the first GA (Generally Available) release of Percona Server 5.6.13-61.0 on October 7th, 2013 (Downloads are available here and from the Percona Software Repositories. Based on MySQL 5.6.13, including all the bug fixes in it, Percona Server 5.6.13-61.0 is the first GA release in the Percona Server 5.6 series. All […]

How to fix your PRM cluster when upgrading to RHEL/CentOS 6.4

If you are using Percona Replication Manager (PRM) with RHEL/CentOS prior to 6.4, upgrading your distribution to 6.4 may break your cluster. In this post I will explain you how to fix your cluster in case it breaks after a distribution upgrade that implies an update of pacemaker from 1.1.7 to 1.18. You can also […]