One of the more popular support requests we get involves setting up the official Percona rsync repositories that can be used to set up local mirrors. I’m glad to announce that this was implemented recently. You can now access the rsync repository at:

rsync://rsync.percona.com/rsync/

Setting up the local mirror can be useful if you have a larger number of systems and you don’t want to download packages from the remote repository multiple times, it can also be useful if the original repository is slower or inaccessible.

Setting up the local repository

Create a folder on disk where the files will be downloaded. Make sure you have enough space for this, currently repository for CentOS 6 is almost 2GB.

[root@percona1]# mkdir -p /data/repo/percona/

After this use createrepo to create all the necessary repository …

Next Wednesday, Severalnines CTO Johan Andersson and I will co-present a webinar about ClusterControl, a cluster management tool created by Severalnines that can monitor Percona XtraDB Cluster. It provides DBAs with the right metrics to manage and optimize applications during development and production.

In the webinar, titled “Performance Monitoring and Troubleshooting of Percona XtraDB Cluster,” we will discuss ClusterControl in general, and then we will explain how to install ClusterControl 1.2.5 in agentless mode. This is a particularly interesting use-case for me because in this …

One of the new features of MySQL 5.6 is the optimizer trace. What does it do? Well, you know Explain, right? Just add Explain before a query and MySQL will print out how it would execute the query. The optimizer trace does that, except it gives you a little more background into to how it makes its decisions. Think of it as “It’s a Wonderful Life” for indexes – it shows you what the world would be like without that primary key or index.

If you ask, why did MySQL choose to run a full table scan vs. an index seek, the optimizer trace can help you get a better picture of the situation. The other big deal with the optimizer trace is that it’ll show you the relative costs of operations. Yeah, MySQL already tells you how many rows it’ll have to read, but now you know how much those cost given the access path (index seek, scan, etc.)

Example

Let’s jump in to see what it looks like. First, enable the optimizer trace …

The MariaDB project is pleased to announce the immediate availability of MariaDB Galera Cluster 5.5.35. This is a Stable release.

See the Release Notes and Changelog for detailed information on this release and the Galera page in the MariaDB Knowledge Base for general information about MariaDB Galera Cluster.

Download MariaDB Galera Cluster 5.5.35

Release Notes …

Before Percona XtraBackup 2.1.7 and Percona XtraDB Cluster 5.6.15-25.3, rsync was the only SST method supporting GTID in the way that it was possible to move an asynchronous slave from one Galera node to another one (related bug).

Indeed, previous versions of Percona XtraBackup didn’t copy any binary log and due to that, moving the async slave to another master, just broke replication (when writes still happened).

Now with the latest version of Percona XtraBackup and Percona XtraDB Cluster, wsrep_sst_xtrabackup-v2 handles the last binlog sent from Percona XtraBackup and allows the move to another …

This week I’ve been writing based on my linux.conf.au 2014 talk, which you can watch the recording of.

Also see Part 1, Part 2, Part 3 and Part 4. My feed feel off Planet MySQL for a bit so you may have missed those posts.

Now we head into the era of acquisitions… there have been a few in …

We are in the middle of switching to GTID based replication from the good old logfile & log position based replication.

But what is GTID? GTID is an abbreviation of ‘GLOBAL TRANSACTION ID’ what speaks for itself: each transaction of a mysql cluster got its globally unique transaction ID, and the DBA have not spend time with positioning slaves, as well as we don’t have to ‘freeze’ any of the servers because of a master failover. The only thing we have to care about: to know what server should be used as a replication master.

OK, what was the problem with the old file-based replication?

Check out this scenario: you have two master servers, called db-master1 and db-master2 and two slaves db-slave1 db-slave2. All the writes are happening on db-master1 and this will replicating to the slaves and the failover master too.

So you have your replication set up, and everything works well. But there is a point when …

The Percona Live MySQL Conference 2014 in Santa Clara, California is just around the corner: April 1-4. There is a tremendous amount of activity leading up to the conference, some of which I will highlight here.

Percona Live MySQL Conference 2014 Keynote Speakers

Oracle’s Tomas Ulin will speak again this year.

I am extremely pleased with the keynote speakers we can now announce. They include speakers from major MySQL users Dropbox and Big Fish Games as well as speakers from influential technology leaders Oracle, Fusion-io, Continuent, and Percona. We are fortunate to once again have Tomas Ulin join us to talk about the future of MySQL including insight into the coming improvements in MySQL 5.7. The list of confirmed speakers and their talks are:

• …

February 13, 2014 By Severalnines

Galera is slowly but surely establishing itself as a credible replacement for traditional MySQL master-slave architectures. 

The benefits are clear - a true multi-master InnoDB setup with built-in fail-over, potentially across data centers. 

But how do you migrate? Does the schema or application change? What are the limitations? Can migration be done online, without service interruption? What are the potential risks, and how to address those?

Webinar: Migrating to MySQL, MariaDB Galera and/or Percona XtraDB Cluster

Tuesday, March 11th 2014

Register now - Europe/MEA/APAC

Register now - North …

The Stackforge Libra project as with most Openstack based projects is written in Python.  As anyone who has used Python before probably knows, Python has something called a GIL (Global Interpreter Lock).  The GIL basically causes Python to only execute one thread at a time, context switching between the threads.  This means you can't really use threads for performance reasons in Python.

One solution to get a little more performance is to use Eventlet.  Eventlet is a library which uses what is called "Green Threads" and hacks on top of the networking libraries to give a mutli-threaded like feel to an application.  As part of this blogging series for HP's Advanced Technology Group I'll write about some of the things I found out the hard way about Eventlet so hopefully you don't hit …