I often talk with people who are very interested in the features of Percona XtraDB Cluster (PXC) such as synchronous and parallel replication, multi-node writing and high availability. However some get confused when operating a real PXC cluster because they do not fully realize the implications of these features. So here is a fun way to test your PXC knowledge: try to solve these 12 questions related to PXC! (you will find the answers at the end of the post.)

Workload

1. With Galera 3.x, support for MyISAM is experimental. When can we expect to have full MyISAM support?
a. This will never happen as Galera is designed for transactional storage engines.
b. This is planned for Galera 4.0.

2. Why aren’t all workloads a good fit for PXC?
a. Execution plans can change compared to a regular MySQL server, so performance is sometimes not as good as with a regular MySQL server.
b. Large …

My webinar “Multi-threaded Replication in MySQL 5.6 and 5.7″ on February 25 generated several excellent questions following the presentation (available here for playback along with the slides). I didn’t have time to answer many of the questions during the session and so in this post I answer all of them. Thanks to everyone who attended!

Q: What do you expect from MTS with logical clock? Do you think performance would be good as with per database?
A: MTS with 5.6 is not usable if you have a single database. I do not have numbers, but this is quite frequent. With 5.7 everyone should be able to benefit from multi-threaded replication.

Q: When MySQL 5.6 was released, performance of MTS was lower, than in 5.5, for example. Is this addressed now?
A: I am not sure which …

This time it is nothing like a linkt to another Blog:  Galera on Mesos

Ok as a fact I was kinda involved. Even the work is done by Stefan all alone. We meat for a day in a coworking space and discussed about Galera and Mesos.
In the end Stefan produced this incredible blogpost and pushed Mesos forward.
Whats the fun about this post?
We already now Galera is already the standard in a lot of architectures. For example OpenStack. Doing consultant work for Docker also I encourage to use Galera for all this infrastructures Docker runs on. 
Mesos is about to run easy on 1000 nodes. It has a nice abstraction of nodes and framework. Companies like Airbnb, Paypal, eBay, Groupon use Mesos. Having a Galera poc for Mesos is going to make it likely to …

Download MariaDB Galera Cluster 10.0.16

Release Notes Changelog What is MariaDB Galera Cluster?

MariaDB APT and YUM Repository Configuration Generator

The MariaDB project is pleased to announce the immediate availability of MariaDB Galera Cluster 10.0.16. This is a Stable (GA) release.

See the …

A Percona Xtradb (Galera) Cluster node may fail to join it due to many possible mistakes causing SST to fail. It could be a configuration item or purely setup requirement. In this article we will be troubleshooting step by step the SST issues faced.

The post Debugging Percona Xtradb (Galera) Cluster node startup / SST errors first appeared on Change Is Inevitable.

Apache CloudStack is a turnkey orchestration platform to deliver IaaS clouds. As a cloud infrastructure scales to hundreds or thousands of servers, with production environments supporting multiple applications and services, high availability becomes a key requirement. Just as for OpenStack, it is possible to deploy the CloudStack management server in a multi-node installation. Since the management server uses a MySQL database to store the state of all its objects, the database could become a single point of failure. The CloudStack manual recommends MySQL replication with manual failover in the event of database loss. We believe there is a better way.

In this blog post, we’ll show you how to deploy redundant CloudStack management servers with …

MySQL 5.6 has an extensive list of new features and changes, so upgrading from a previous version can be risky if not tested extensively. For this reason, we recommend our users to read and understand the changes before doing the upgrade. If you are on older MySQL versions, it is probably time to think about upgrading. MySQL 5.6 was released in February 2013, that’s almost two years ago!

A major upgrade, e.g., from MySQL 5.5 to 5.6 or MariaDB 5.5 to 10, requires the former MySQL/MariaDB server related packages to be uninstalled. In Galera Cluster, there are two ways to upgrade; either by performing offline upgrade (safer, simpler, requires service downtime) or online upgrade (more complex, no downtime). 

In this blog post, we are going to show you how to perform an offline upgrade on Galera-based …

There will be a MySQL & Friends Devroom at the FOSDEM 2015 this year.And surprisingly my talk - not sure you can call 15 min a talk  - had been accepted. (There are other accepted talks of course.) 
It will be a dense talk about Docker/MySQL/Galera :)
We are (at least me) are going to have fun \o/ Erkan
I hope there will be an official announcement too.  

January 5, 2015 By Severalnines

Cloud storage is hot. Dropbox, Apple iCloud, Google Drive, Microsoft SkyDrive and Amazon Cloud Drive all offer cloud sharing platforms where you can store documents in the cloud and access them from all your devices. For enterprises who require full control, ownCloud is an open source solution that allows files to be stored on-premises and/or a backend cloud. 

In this blog post, we’ll show you how to deploy a high availability setup using ownCloud Community Edition. We will need to set up redundancy in each of the following layers:

• file storage
• web server
• database server
• load balancer

We will use five servers. ownCloud will run on three separate servers with MySQL Galera Cluster 5.6 and GlusterFS running on RHEL 6.5 64bit. ownCloud supports GlusterFS as primary storage. ClusterControl will be co-located …

State Snapshot Transfer (SST) is used in Percona XtraDB Cluster (PXC) when a new node joins the cluster or to resync a failed node if Incremental State Transfer (IST) is no longer available. SST is triggered automatically but there is no magic: If it is not configured properly, it will not work and new nodes will never be able to join the cluster. Let’s have a look at a few classic issues.

Port for SST is not open

The donor and the joiner communicate on port 4444, and if the port is closed on one side, SST will always fail.

You will see in the error log of the donor that SST is started:

[...]
141223 16:08:48 [Note] WSREP: Node 2 (node1) requested state transfer from '*any*'. Selected 0 (node3)(SYNCED) as donor.
141223 16:08:48 [Note] WSREP: Shifting SYNCED -> DONOR/DESYNCED (TO: 6)
141223 16:08:48 …