October 22, 2014

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 net_write_timeout vs wait_timeout and protocol notes

In my previous post I mentioned you might need to increase net_write_timeout to avoid connection being aborted and now I think I should have better explained that. MySQL uses a lot of different timeout variables at different stages. For example when connection is just being established connect_timeout is used. When server waits for another query […]

Pitfalls of converting to InnoDB

We often recommend to our clients to convert their current database from MyISAM tables to InnoDB. The transfer by itself in most cases is almost plain, however the application can be broken by new unexpected errors 1205 (ER_LOCK_WAIT_TIMEOUT) Lock wait timeout expired. Transaction was rolled back. 1213 (ER_LOCK_DEADLOCK) Transaction deadlock. You should rerun the transaction.

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 […]

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 […]

Before every release: A glimpse into Percona XtraDB Cluster CI testing

I spoke last month at linux.conf.au 2014 in Perth, Australia, and one of my sessions focused on the “Continuous Integration (CI) testing of Percona XtraDB Cluster (PXC)” at the Developer,Testing, Release and CI miniconf. Here is the video of the presentation: Here is the presentation itself: Percona XtraDB Cluster before every release: Glimpse into CI […]

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 […]

Percona XtraBackup 2.1.2 for MySQL available for download

Percona is glad to announce the release of Percona XtraBackup 2.1.2 for MySQL on May 18, 2013. Downloads are available from our download site here and Percona Software Repositories. This release fixes number of high-priority bugs since version 2.1 became GA. It’s advised to upgrade your latest 2.1 version to 2.1.2. This release is the […]

Virident vCache vs. FlashCache: Part 2

This is the second part in a two-part series comparing Virident’s vCache to FlashCache. The first part was focused on usability and feature comparison; in this post, we’ll look at some sysbench test results. Disclosure: The research and testing conducted for this post were sponsored by Virident. First, some background information. All tests were conducted […]

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 […]