Now that Percona XtraDB Cluster 5.6 is out in beta, I wanted to start a series talking about new features in Galera 3 and PXC 5.6.  On the surface, Galera 3 doesn’t reveal a lot of new features yet, but there has been a lot of refactoring of the system in preparation for great new features in the future.

Galera vs MySQL options

wsrep_provider_options is a semi-colon separated list of key => value configurations that set low-level Galera library configuration.  These tweak the actual cluster communication and replication in the group communication system.  By contrast, other PXC global variables (like ‘wsrep%’) are set like other mysqld options and generally have more to do with MySQL/Galera …

November 14, 2013 By Severalnines

Database schema changes are usually not popular among DBAs or sysadmins, not when you are operating a cluster and cannot afford to switch off the service during a maintenance window. There are different ways to perform schema changes, some procedures being more complicated than others. We invited Seppo from the Codership team to tell us about the options. If you’d like to learn more, please register for our new webinar.

Webinar: Galera Cluster Best Practices - Zero Downtime Schema Changes

Tuesday, December 3rd 2013

Register now - Europe/MEA/APAC

…

November 4, 2013 By Severalnines Percona Live London MySQL Conference - 11-12th November, 2013

We’re particularly excited about this year’s Percona Live London MySQL Conference. The line-up of speakers & topics looks excellent and it’s good to see speakers from Oracle, Percona, the MariaDB Foundation (amongst others) scheduled at the same event. It demonstrates not just the diversity of the ever broadening MySQL ecosystem, but also the fact that there really is room for everyone to contribute, participate in and advance MySQL in manifold directions while still retaining a certain amount of uniformity.

And this is how we will be contributing to the event ...

Talk - MySQL Cluster Performance Tuning By Johan Andersson, CTO & Co-Founder, Severalnines

Correct tuning of MySQL NDB Cluster can have dramatic impact on …

MySQL Fabric is a very promising sharding framework. If I take Ulf Wendel definition of MySQL Fabric :

MySQL Fabric is an administration tool to build large “farms” of MySQL servers. In its most basic form, a farm is a collection of MySQL Replication clusters. In its most advanced form, a farm is a collection of [...]

The Percona Monitoring Plugins (PMP) provide some free tools to make it easier to monitor PXC/Galera nodes.  Monitoring broadly falls into two categories: alerting and historical graphing, and the plugins support Nagios and Cacti, respectively, for those purposes.

Graphing

An update to the PMP this summer (thanks to our Remote DBA team for supporting this!) added a Galera-specific host template that includes a variety of Galera-related stats, including:

• Replication …

October 28, 2013 By Severalnines

Data protection is vital for DB admins, especially when it involves data that is accessed and updated 24 hours a day. Clustering and replication are techniques that provide protection against failures, but what if a user or DBA issues a detrimental command against one of the databases? A user might erroneously delete or update the contents of one or more tables, drop database objects that are still needed during an update to an application, or run a large batch update that fails midway. How do we recover lost data? 

In a previous post, we showed you how to do a full restore from backup. Great, now you’ve restored up to the last incremental backup that was done at 6am this morning. But how about the rest of the data?

This is where you’d do a …

October 23, 2013 By Severalnines

Last week, the Severalnines & Codership teams came together to co-host two webinar sessions on Galera 3.0, MySQL 5.6, Global Transaction IDs and WAN. The sessions were held during EMEA/APAC as well as NA/LATAM timezones, which worked out quite nicely. Our speakers were Seppo Jaakola from Codership & Vinay Joosery from Severalnines. 

Webinar topics:

• Galera Cluster features and benefits
• Support for MySQL 5.6
• Integration with MySQL Global Transaction Identifiers
• Mixing Galera synchronous replication and asynchronous MySQL replication
• Deploying in WAN and Cloud …

October 16, 2013 By Severalnines

Galera uses a preallocated file with a specific size called gcache, used to store the writesets in circular buffer style. By default, its size is 128MB. In this post, we are going to explore how to leverage gcache to improve the operation of a Galera cluster.

Test Case

We have a four node Galera cluster, using the latest release 23.2.7(r157). We have a table called t1 that is replicated by Galera on all nodes. The cluster nodes have allocated the default 128MB gcache.size, and we’ll try to execute a large writeset to see how gcache responds.

mysql> SHOW VARIABLES LIKE …

September 25, 2013 By Severalnines

Join this technical webinar to learn about the new features in the latest Galera 3.0 release.

You'll learn how Galera integrates with MySQL 5.6 and Global Transaction IDs to enable cross-datacenter and cloud replication over high latency networks. The benefits are clear; a globally distributed MySQL setup across regions to deliver Severalnines availability and real-time responsiveness.

DATE & TIME

Europe/MEA/APAC

read more

Percona XtraDB Cluster (PXC) is different enough from async replication that it can be a bit of a puzzle how to do things the Galera way.  This post will attempt to illustrate the basics of setting up 2 node PXC cluster from scratch.

Requirements

Two servers (could be VMs) that can talk to each other.  I’m using CentOS for this post.  Here’s a dirt-simple Vagrant setup: https://github.com/jayjanssen/two_centos_nodes to make this easy (on Virtualbox).

These servers are talking over the 192.168.70.0/24 internal network for our example.

jayj@~/Src $ git clone https://github.com/jayjanssen/two_centos_nodes.git
jayj@~/Src $ cd two_centos_nodes
jayj@~/Src/two_centos_nodes $ vagrant up
 Bringing machine 'node1' up …