The latest from the MySQL community

I have been working for a very large Australian website for over six years and during this period have been fortunate enough to hire many Infrastructure Operations Engineers that now work for that company. I want to detail the evolution of the hiring process and what I have driven it to over the last six years.
How was I hired This is the interview process I went through at my current company:

• A technical and cultural pre-screening from a recruiter
• A short phone interview with a small set of adhoc questions around technical skill set. How does DNS work?
• An hour long face to face interview with the hiring manager and another senior engineer testing both technical capability and culture fit
• Another hour long face to face interview with a HR representative testing cultural fit 
• Lastly, a reference check to confirm technical capability and cultural fit performed over …

Over on the codecentric blog I just published a new post on True KVM Live Migration with OpenStack Icehouse and Ceph based VM storage, outlining the process it took me to get this actually working. There were several issues to work around, some of them bugs in OpenStack, some of them home-grown issues.

I provide a few patches to OpenStack classes as well as a description of what is actually going wrong and how to circumvent the problems. So head right over and have fun reading :)

Have you ever had a case where you needed to find a process which sent a HUP/KILL/TERM or other signal to your database? Let me rephrase. Did you ever have to find which process messed up your night? If so, you might want to read on. I’m going to tell you how you can find it.

Granted, on small and/or meticulously managed systems tracking down the culprit is probably not a big deal. You can likely identify your process simply by checking what processes have enough privileges to send mysqld a HUP/KILL/TERM signal. However, frequently we see cases where this may not work or the elimination process would be too tedious to execute.

We recently had a case where a process was frequently sending SIGHUPs to mysqld and the customer asked us to see if we could get rid of his annoyance. This blog is the direct result of a discussion I had with my colleague …

Thanks to everyone who attended and participated in last week’s webinar on 'Galera Cluster for MySQL vs MySQL (NDB) Cluster: A High Level Comparison'. If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.

In this webinar, Severalnines VP of Products, Alex Yu, who was part of the team at Ericsson who originally developed the NDB storage engine in 2001, gave an overview of the two clustering architectures and discussed their respective strengths and weaknesses: 

1. MySQL Cluster architecture: strengths and limitations
2. Galera Architecture: strengths and limitations
3. Deployment scenarios
4. Data migration
5. Read and write workloads (Optimistic/pessimistic locking)
6. WAN/Geographical replication
7. Schema changes
8. Management and monitoring …

At Data2Day 2014 in Karlsruhe I talked about the Ceph Storage Cluster and us using it to store documents in CenterDevice. These are the slides (German) I used. If you are interested in Ceph and/or look for help implementing it, don't hesitate to contact me.

Ceph Object Store from Daniel Schneller

November 14, 2014 By Severalnines

Thanks to everyone who attended and participated in this week's webinar on '9 DevOps Tips for Going in Production with Galera Cluster for MySQL'. If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.

In this webinar, Severalnines CTO Johan Andersson discussed 9 key aspects to consider before taking Galera Cluster for MySQL into production:

• 101 Sanity Check
• Operating System
• Backup Strategies
• Galera Recovery
• Query Performance
• Schema changes
• Security / Encryption
• Reporting
• Protecting from Disasters

Watch the replay 9 DevOps Tips for Going in …

September 22, 2014 By Severalnines

Need to add phone and SMS alerting to ClusterControl? ClusterControl 1.2.8 introduces support for PagerDuty, an alerting service for Ops teams to schedule on-calls and add phone and SMS notifications to IT tools. By integrating PagerDuty with ClusterControl, you can start receiving phone, SMS and email notifications for all important database events as monitored by ClusterControl. Alerts go directly to the right person who can solve the issue.

This integration is possible thanks to a new plugin interface, that takes ClusterControl alarms in JSON format and outputs to an external system via plugins. Plugins can be either scripts or executable binaries.

We have built a few example …

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 […]

Another post on Ansible over on the codecentric blog: Jinja2 for better Ansible playbooks and templates linked here for your convenience :)

August 25, 2014 By Severalnines

Are you going in production with Galera Cluster for MySQL? Here are 9 tips to consider before going live. These are applicable to all 3 Galera versions (Codership, Percona XtraDB Cluster and MariaDB Galera Cluster). 

1. Galera strengths and weaknesses

There are multiple types of replication and cluster technologies for MySQL, make sure you understand how Galera works so you set the right expectations. Applications that run on single instance MySQL might not work well on Galera, you might need to make some changes to the application or the workload might not be appropriate. We’d suggest you have a look at these resources: 

• Tutorial on …