November 25, 2014

How FLUSH TABLES WITH READ LOCK works with Innodb Tables

Many backup tools including Percona Xtrabackup, MyLVMBackup and others use FLUSH TABLES WITH READ LOCK to temporary make MySQL read only. In many cases the period for which server has to be made read only is very short, just few seconds, yet the impact of FLUSH TABLES WITH READ LOCK can be quite large because […]

How fast is FLUSH TABLES WITH READ LOCK?

A week or so ago at the MySQL conference, I visited one of the backup vendors in the Expo Hall. I started to chat with them about their MySQL backup product. One of the representatives told me that their backup product uses FLUSH TABLES WITH READ LOCK, which he admitted takes a global lock on […]

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 […]

Typical misconceptions on Galera Replication for MySQL

Even if a Galera node looks like a regular MySQL server, the underlying replication mechanism is very different. This implies some changes in the way you have to configure the Galera nodes. Here are some of the most common misconceptions about Galera when using Percona XtraDB Cluster. Q: Why should I enable binary logging as […]

Log rotate and the (deleted) MySQL log file mystery

Did your logging stop working after you set up logrotate? Then this post might be for you. Some time ago, Peter Boros wrote about Rotating MySQL Slow Logs safely, explaining the steps of a “best practice” log rotate/archive. This post will add more info about the topic. When running logrotate for MySQL (after proper setting […]

Facebook MySQL database engineers ready for Percona Live London 2014

With 1.28 billion active users, Facebook MySQL database engineers are active and extremely valuable contributors to the global MySQL community. So naturally they are also active participants of Percona Live MySQL conferences! And next week’s Percona Live London 2014 (Nov. 3-4) is no exception. (Register now and use the promotional code “Facebook” to save £30!) […]

How to close POODLE SSLv3 security flaw (CVE-2014-3566)

Padding Oracle On Downgraded Legacy Encryption First off, the naming “convention” as of late for security issues has been terrible. The newest vulnerability (CVE­-2014-3566) is nicknamed POODLE, which at least is an acronym and as per the header above has some meaning. The summary of this issue is that it is much the same as the […]

MySQL upgrade best practices

MySQL upgrades are necessary tasks and we field a variety of questions here at Percona Support regarding MySQL upgrade best practices. This post highlights recommended ways to upgrade MySQL in different scenarios. Why are MySQL upgrades needed? The reasons are many and include: Access to new features, performance benefits, bug fixes…. However, MySQL upgrades can […]

mysqld_multi: How to run multiple instances of MySQL

The need to have multiple instances of MySQL (the well-known mysqld process) running in the same server concurrently in a transparent way, instead of having them executed in separate containers/virtual machines, is not very common. Yet from time to time the Percona Support team receives a request from a customer to assist in the configuration of […]

What I learned while migrating a customer MySQL installation to Amazon RDS

Hi, I recently had the experience of assisting with a migration of a customer MySQL installation to Amazon RDS (Relational Database Service). Amazon RDS is a great platform for hosting your MySQL installation and offers the following list of pros and cons: You can scale your CPU, IOPS, and storage space separately by using Amazon […]