I’m looking forward to next week’s MySQL webinar with Robert Hodges, CEO of Continuent. We’ll be speaking on the topic “Multi-Data Center MySQL with Continuent Tungsten.”

You’re not alone if you’ve been vexed when trying to assemble multi-master, multi-site MySQL clusters. Whether that was a move from a single database server to a scalable cluster, or from a brittle MySQL replication system to a transparent, manageable database cluster.

We’ve all been there at one point or another in our careers. So learn from our experience. In our joint webinar next week (Dec. 11), Robert and I will …

December 4, 2013 By Severalnines

As OpenStack deployments mature from evaluation/development to production environments supporting apps and services, high-availability becomes a key requirement. In a previous post, we showed you how to cluster the database backend - which is central to the operation of OpenStack. In that setup, you would have two controllers, while placing a 3-node Galera cluster on separate hosts. Now, it can be quite a leap to go from one VM with all services running on it, to a fully distributed setup with 5 VMs. The good news is that you can have a highly available setup starting with just 3 VMs.

In this post, we are going to show you how to cluster OpenStack Havana in a minimal node setup with 2 controllers and one compute node. Our controllers will be running all OpenStack services, as well as clustered RabbitMQ …

The first thing any MySQL user learns is mysql -u user database -p to use the mysql client program to connect with an instance. In this case the user will be prompted for the password and the given password will be encrypted before being passed to the server as part of the authentication process. Some folks (and the majority of scripts) will use -p password on the com
I yanked out the binary atamand line which is less secure as the password is in plain text for anyone privileged or sneaky to see. You could put the password in the ~.my.cnf file but once again the password is there in plain text.

MySQL 5.6 introduced the mysql_config_editor that stores authentication credentials in an encptryed file named .mylogin.cnf in your home directory. MySQL client programs can read this file. No exposure of the password on the …

I recently came across an issue trying to connect to a MySQL server using the mysql client. It appeared as through the connection was hanging.

A subsequent connection using the -A option highlighted the problem with the previous connection stuck in the state “Waiting for table metadata lock”.

mysql> SHOW PROCESSLISTG
*************************** 1. row ***************************
     Id: 37
   User: root
   Host: localhost
     db: tmp
Command: Query
   Time: 90
  State: preparing
   Info: create table missing as select id from AK where id not in (select id ..
*************************** 2. row ***************************
     Id: 38
   User: root
   Host: localhost
     db: tmp
Command: Field List
   Time: 50
  State: Waiting for table metadata lock
   Info:
*************************** 3. row ***************************
     Id: 39
   User: root
   Host: localhost
     db: tmp
Command: Query
   Time: 0
  State: init
   Info: show processlist …

What is SeaLion?

SeaLion is a Linux monitoring tool, built from the ground up for troubleshooting hundreds of servers.

Why did we create SeaLion?

We’ve another product line - CloudMagic which is a search centric email app. We manage petabytes of indexed user data spread across hundreds of servers. This data is hosted on AWS. Being a search centric email app, the search speed is critical. We take pride in being known for blazing fast search speeds. When a search query takes more than the threshold value, we get an alert and we debug.

Typically, it’s important at this point to determine if the issue was with the hosting provider or in our code. Inspite of having a suite of monitoring tools, we always fall back to the output of traditional commands. What took time? We check the usual suspects …

Percona is glad to announce the release of Percona XtraDB Cluster 5.5.34-25.9 on December 4, 2013. Binaries are available from the downloads area or from our software repositories.

Based on Percona Server 5.5.34-32.0 including all the bug fixes in it, Galera Replicator and on Codership wsrep API 5.5.34-25.9, Percona XtraDB Cluster …

INFORMATION_SCHEMA is usually the place to go when you want to get facts about a system (how many tables do we have? what are the 10 largest tables? What is data size and index size for table t?, etc). However it is also quite common that such queries are very slow and create lots of I/O load. Here is a tip to avoid theses hassles: set innodb_stats_on_metadata to OFF.

This is a topic we already talked about, but given the number of systems suffering from INFORMATION_SCHEMA slowness, I think it is good to bring innodb_stats_on_metadata back on the table.

The problem

Let’s look at a system I’ve seen recently: MySQL 5.5, working set fitting in memory but not the whole dataset, around 4000 InnoDB tables.

The I/O load is very light as …

The MySQL community came together last month for two days of outstanding technical tutorials and sessions at Percona Live London. And now many of those MySQL presentations are available for free download.

This year’s London conference saw a 20 percent spike in attendance compared with last year, with MySQL professionals from 31 countries gathering in the U.K. capital for compelling keynotes (including Oracle’s Tomas Ulin and Percona’s Peter Zaitsev) along with in-depth tutorials and insightful breakout sessions.

And as a “thank you” for your continuing support of the Percona Live series of conferences, we’re also offering an additional $25 off registration for April’s Percona Live MySQL Conference and Expo 2014 (April 1-4 at the Hyatt Regency Santa …

Heads up that Friday (6th December) is your last chance to submit a 30 minute session proposal for next year’s MySQL & Friends Devroom at FOSDEM. I presented last year and I was really impressed by the number of attendees, the organisation and the positive reception (I’ll be there again next year – hopefully presenting). If you’ve got a MySQL-related topic that you’d like to present to an enthusiastic open-source community then this is a agreat opportunity.

Submit your proposal(s) for a 30 minute session here.

FOSDEM 2014 is free event running in Brussels over the weekend of 1st & 2nd February, with the MySQL content aimed for the Saturday. This is a huge event (5,000+) and has a great, …

I get a lot of questions about Percona XtraDB Cluster 5.6 (PXC 5.6), specifically about whether such and such MySQL 5.6 Community Edition feature is in PXC 5.6.  The short answer is: yes, all features in community MySQL 5.6 are in Percona Server 5.6 and, in turn, are in PXC 5.6.  Whether or not the new feature is useful in 5.6 really depends on how useful it is in general with Galera.

I thought it would be useful to highlight a few features and try to show them working:

Innodb Fulltext Indexes

Yes, FTS works in Innodb in 5.6, so why wouldn’t it work in PXC 5.6?  To test this I used the Sakila database , which contains a single table with FULLTEXT.  In the sakila-schema.sql file, it is still designated a MyISAM table: