April 20, 2014

Apache PHP MySQL and Runaway Scripts

Sometimes due to programming error or due to very complex query you can get your PHP script running too long, well after user stopped waiting for the page to render and went browsing other sites. Looking at Server-Status I’ve seen scripts executing for hours sometimes which is obviously the problem – they take Apache Slot, […]

Debugging sleeping connections with MySQL

Have you ever seen connection in the SHOW PROCESSLIST output which is in “Sleep” state for a long time and you have no idea why this would happen ? I see if frequently with web applications and it is often indication of trouble. Not only it means you may run out of MySQL connections quicker […]

Wishes for new “Pure PHP” MySQL driver

If you’re following MySQL or PHP landscape you should have seen announcement by MySQL to develop pure PHP driver. If not – Here is FAQ . I’m to meet the team (Georg, Andrey etc) which will be developing this driver during my visit to Open Source Database Conference in November so I thought it would […]

MySQL Query Cache

MySQL has a great feature called “Query Cache” which is quite helpful for MySQL Performance optimization tasks but there are number of things you need to know. First let me clarify what MySQL Query Cache is – I’ve seen number of people being confused, thinking MySQL Query Cache is the same as Oracle Query Cache […]

Introducing backup locks in Percona Server

TL;DR version: The backup locks feature introduced in Percona Server 5.6.16-64.0 is a lightweight alternative to FLUSH TABLES WITH READ LOCK and can be used to take both physical and logical backups with less downtime on busy servers. To employ the feature with mysqldump, use mysqldump –lock-for-backup –single-transaction. The next release of Percona XtraBackup will […]

Percona XtraDB Cluster 5.6 GA release now available

Percona is pleased to announce the first General Availability release of the leading open source High Availability solution for MySQL, Percona XtraDB Cluster 5.6 on January 30, 2014. Binaries are available from downloads area or from our software repositories. Percona XtraDB Cluster 5.6 Percona XtraDB Cluster 5.6 is an active/active cluster solution for High Availability (HA) MySQL […]

The use of Iptables ClusterIP target as a load balancer for PXC, PRM, MHA and NDB

Most technologies achieving high-availability for MySQL need a load-balancer to spread the client connections to a valid database host, even the Tungsten special connector can be seen as a sophisticated load-balancer. People often use hardware load balancer or software solution like haproxy. In both cases, in order to avoid having a single point of failure, […]

A closer look at Percona Server 5.6

Yesterday we announced the GA release of Percona Server 5.6, the latest release of our enhanced, drop-in replacement for MySQL. Percona Server 5.6 is the best free MySQL alternative for demanding applications. Our third major release, Percona Server 5.6 offers all the improvements found in MySQL 5.6 Community Edition plus scalability, availability, backup, and security […]

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 […]

Automation: A case for synchronous replication

Just yesterday I wrote about math of automatic failover today I’ll share my thoughts about what makes MySQL failover different from many other components and why asynchronous nature of standard replication solution is causing problems with it. Lets first think about properties of simple components we fail over – web servers, application servers etc. We […]