August 20, 2014

Percona XtraDB Cluster: Failure Scenarios with only 2 nodes

During the design period of a new cluster, it is always advised to have at least 3 nodes (this is the case with PXC but it’s also the same with PRM). But why and what are the risks ? The goal of having more than 2 nodes, in fact an odd number is recommended in […]

How to diagnose errors in the MySQL error log

I frequently see questions about how to understand the nature of errors in MySQL’s error log. Now, there is a lot of complexity to this — the flowchart would be quite large, as with any nontrivial piece of software. But there is one particular class of errors that is relatively easy to diagnose, if you […]

Percona XtraDB Cluster Feature 2: Multi-Master replication

This is about the second great feature – Multi-Master replication, what you get with Percona XtraDB Cluster. It is recommended you get familiar with general architecture of the cluster, described on the previous post. By Multi-Master I mean the ability to write to any node in your cluster and do not worry that eventually you […]

Percona Testing: Innodb crash / recovery tests available

Not everyone may know this, but there are precious few innodb crash recovery tests available. Some folks have noticed this and asked for something to be done about it, but unfortunately, no tests have been created for the main MySQL branch. The MySQL at Facebook branch has a number of tests that are quite interesting.  […]

Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit

It is no secret that bugs related to multithreading–deadlocks, data races, starvations etc–have a big impact on application’s stability and are at the same time hard to find due to their nondeterministic nature.  Any tool that makes finding such bugs easier, preferably before anybody is aware of their existence, is very welcome.

More on MySQL Error Messages

I wrote about MySQL Error Messages before and as you might guess I’m not very happy with quality for error messages it produces. Now I’m revisiting this subject with couple of more annoying examples I ran into during last couple of days.

Tokyo Tyrant – The Extras Part I : Is it Durable?

You know how in addition to the main movie you have extras on the DVD.  Extra commentary, bloopers, extra scenes, etc? Well welcome the Tyrant extras.  With my previous blog posts I was trying to set-up a case for looking at NOSQL tools, and not meant to be a decision making tool.  Each solution has […]

Air traffic queries in InfiniDB: early alpha

As Calpont announced availability of InfiniDB I surely couldn’t miss a chance to compare it with previously tested databases in the same environment. See my previous posts on this topic: Analyzing air traffic performance with InfoBright and MonetDB Air traffic queries in LucidDB I could not run all queries against InfiniDB and I met some […]

MySQL Error Message Nonsenses

What MySQL honestly was never good at is giving good helpful error messages. Start with basics for example – The error message in case of syntax error gives you information about tokens near by but little details:

It would be much better if MySQL would give error give exact position of error (with complex […]

Percona Toolkit 2.2.10 is now available

Percona is glad to announce the release of Percona Toolkit 2.2.10 on August 8, 2014 (downloads are available here and from the Percona Software Repositories). This release is the current GA (Generally Available) stable release in the 2.2 series. Bugs Fixed: Fixed bug 1287253: pt-table-checksum would exit with error if it would encounter deadlock when doing checksum. This was […]