Recently we faced an issue when Nagios reported significant amount of “Locked” queries.
To investigate and debug the issue we needed to get more insight about the state of MySQL and the OS at the time the locks occurred.
This is how we got the much needed information:


wget http://bit.ly/1ltoZtk -O pt-stalk
chmod +x pt-stalk
mkdir -p /tmp/pt-stalk
sudo pt-stalk --daemonize --notify-by-email <EMAIL> --log /tmp/pt-stalk/pt-stalk.log --user root --dest /tmp/pt-stalk --function processlist --variable State --match Locked --threshold 20 --cycles=10 --sleep=15 --run-time=15


In this case we are running pt-stalk utility in background and trying to catch the case when there are 20+ Locked queries in processlist. When a match occurs, pt-stalk will collect a lot of OS and MySQL info and notify us by email.

Join 27,000 others and follow Sean Hull on twitter @hullsean. I was shocked to find this article on ReadWrite: The Truth About DevOps: IT Isn’t Dead; It’s not even Dying. Wait a second, do people really think this? Truth is I have heard whispers of this before. I was at a meetup recently where the […]

It has been just over 2 weeks since the last libAttachSQL version was released.  I had a great vacation in the middle which for once meant that I didn't do any work for the week I was away :)

For those who don't know about it, libAttachSQL is a lightweight, non-blocking C connector for MySQL servers.  It is Apache 2.0 licensed so plays well with both Open Source and Commercially licensed applications.  I have been developing it for 2 months now as part of my work for HP's Advanced Technology Group.  It is hosted on GitHub and uses many freely available tools (such as Travis CI) to host and test various parts of the project.

Once again I thank everyone for the feedback I have received. …

The MySQL for Database Administrators training course is one of the most popular courses at Oracle. This is not surprising since it provides a comprehensive range of administration skills to those using the world's most popular open source database.

You can travel to an education center to take this 5-day instructor-led course, and as shown in the table below, events are currently scheduled for delivery in 8 languages (Arabic, Brazilian Portuguese, English, French, Hebrew, Italian, Spanish, Turkish).

If you want to take this training from your own desk, you have two options:

• Training-on-Demand: Start training within 24 hours of registration, following training at your own pace.
• Live-Virtual Event: Follow a live event …

Galera replication for MySQL brings not only the new, great features to our ecosystem, but also introduces completely new maintenance techniques. Are you concerned about adding such new complexity to your MySQL environment? Perhaps that concern is unnecessarily.

I am going to present here some simple tips that hopefully will let fresh Galera users prevent headaches when there is the need to recover part or a whole cluster in certain situations. I used Percona XtraDB Cluster (project based on Percona Server and Galera library + MySQL extensions from Codership) to prepare this post, but most if not all of the scenarios should also apply to any solution based on MySQL+Galera tandem you actually chose, whether these are binaries from Codership, MariaDB Galera Cluster or …

September 1, 2014 By Severalnines

According to Forrester, a DBA in a large enterprise manages between 8 and 275 databases, with the industry average being 40 databases to a DBA. Larger databases usually require extra effort around tuning, backup, recovery and upgrade. Cloud, as well as automation and management tools can help improve the number of databases managed by one DBA.  

With that background, we were pretty excited to introduce support for management of single-instance MySQL and MariaDB databases in ClusterControl 1.2.6. The majority, if not all of the cluster users out there, use single-instance or master-slave replicated setups along their mission-critical …

To get more familiar with docker and to create a test setup for MySQL Cluster I created docker images for the various components of MySQL Cluster (a.k.a. NDB Cluster)

At first I created a Fedora 20 container and ran all components in one container. That worked and is quite easy to setup. But that's not how one is supposed to use docker.

So I created Dockerfile's for all components and one base image.

The base image:

• contains the MySQL Cluster software
• has libaio installed
• has a mysql user and group 
• serves as a base for the other images

The management node (ndb_mgmd) image:

• Has ndb_mgmd as entrypoint
• Has a config.ini for the cluster …

After mysql installation, To make mysql server production ready we have to tune default mysql variables considering the hardware, production load, performance, durability etc.

But What about the optimizing  Linux OS settings  with mysql ?

Here it is, i encountered  an issue once when i was checking TOP output for mysqld process and found that the mysqld  memory continuously increasing. Also there was one more thing  that it was using swap memory even if there was enough RAM memory available. we have monitored for a week and this was causing an issue like slow query processing, performance and slowness on DB server.

To solve this problem we have to set correct swappiness

•       To check vm.swappiness

          …

I was talking with a Percona Support customer earlier this week who was looking for Galera data on Percona Cloud Tools. (Percona Cloud Tools, now in free beta, is a hosted service providing access to query performance insights for all MySQL uses.)

The customer mentioned they were already keeping track of some Galera stats on Cacti, and given they were inclined to use Percona Cloud Tools more and more, they wanted to know if it was already supporting Percona XtraDB Cluster. My answer was: “No, not yet: you can install agents in each node (the regular way in the first node, then …

I was talking with a Percona Support customer earlier this week who was looking for Galera data on Percona Cloud Tools. (Percona Cloud Tools, now in free beta, is a hosted service providing access to query performance insights for all MySQL uses.)

The customer mentioned they were already keeping track of some Galera stats on Cacti, and given they were inclined to use Percona Cloud Tools more and more, they wanted to know if it was already supporting Percona XtraDB Cluster. My answer was: “No, not yet: you can install agents in each node (the regular way in the first node, then …