I’ve previously provided an example of using MySQL Cluster Manager to add nodes to a running MySQL Cluster deployment but I’ve since received a number of questions around how to do this in more complex circumstances (for example when ending up with more than 1 MySQL Server on a single host where each mysqld process should use a different port). The purpose of this post is to work through one of these more complex scenarios.

The starting point is an existing cluster made up of 3 hosts with the nodes (processes) as described in this MCM report:

mcm> SHOW STATUS -r mycluster;
+--------+----------+-------------------------------+---------+-----------+---------+
| NodeId | Process  | Host                          | Status …

I've been dealing with MySQL Cluster in one way or another since around 2005 or so (back in the MySQL 4.1 days) but it is still full of "funny" surprises. This post is a collection of different locking related issue i ran into during the previous weeks that i had not been aware of up to now (or simply may have forgotten over time)

== Unique hash indexes lock exclusively ==

This is the one that regular users are most likely to run into: in general row logs in MySQL Cluster distinguish between reads and writes so that writers can block other writers, but not readers and readers from other transactions always see the last committed row value (Cluster currently only supports the READ COMMITTED isolation level). As soon as you have a secondary unique index in addition to a primary key things are different though. Internally a unique index that is not the primary key is implemented as a unique hash index in Cluster (and optionally also …

Schema-free NoSQL Data

Update – the webinar replay is now available from here.

On Thursday, I’ll be presenting a webinar on NoSQL (of course with a MySQL twist!) – as always it’s free to attend but you need to register here in advance. Even if you can’t attend, it’s worth registering as you’ll be sent a link to the replay and the charts. The session will introduce the concepts and motivations behind the NoSQL movement and then go on to explain how you can get most of the same benefits with MySQL (including MySQL Cluster) while still getting the RDBMS benefits such as ACID transactions.

The …

Yesterday we ran a webinar discussing the demands of next generation web services and how blending the best of relational and NoSQL technologies enables developers and architects to deliver the agility, performance and availability needed to be successful.

Attendees posted a number of great questions to the MySQL developers, serving to provide additional insights into areas like auto-sharding and cross-shard JOINs, replication, performance, client libraries, etc. So I thought it would be useful to post those below, for the benefit of those unable to attend the webinar.

Before getting to the Q&A, there are a couple of other resources that maybe useful to those looking at NoSQL capabilities within MySQL:

- On-Demand webinar

- …

The binary version for MySQL Cluster 7.2.5 has now been made available at http://www.mysql.com/downloads/cluster/ (GPL version) or https://support.oracle.com/ (commercial version).

A description of all of the changes (fixes) that have gone into MySQL Cluster 7.2.5 (compared to 7.2.4) will appear in the 7.2.5 Change log.

Check out this MySQL Cluster 7.2 Demo

From the Cluster 7.2 Demo

if you have missed any of the new features.

And upcoming MySQL Webcasts on Cluster, MySQL on Windows, MySQL Enterprise Edition, NoSQL access to MySQL, and Building High Performance and High Traffic PHP applications are available for registration!

…

Many Windows users first looking to experiment with MySQL Cluster may find the process of getting everything up and running daunting.  Fortunately, there’s MySQL Cluster Manager (MCM) which can help jump-start that process – and that’s all many people will need.

In my work, I frequently have to install specific version of MySQL Server or Cluster to validate behavior of a handful of commands, and MCM is a bit overkill.  I have a couple of tricks that I use to quickly set up MySQL Cluster on Windows environments:

1. I always use the .ZIP packages
2. I have a set cluster data directory (in my case, D:\cluster-data)
3. I have a standard Cluster configuration file (config.ini) that I use, with two data nodes, one management node, and two …

Someone will win a limited edition and very rare MySQL Cluster 7.2 shirt today

Someone will win this shirt at the North Texas MySQL User Group meeting on Monday March 12th

at the North Texas MySQL Users Group Meeting. Many other prizes including thumb drives, buttons, and lanyards plus we will have pizza. Please RSVP to make sure we get enough food!

The presentation will be on MySQL 5.6 + 20 MySQL Tips in 20 Minutes!

Date: Monday, March 12, 2012 Remind Me
Time: 4:45 PM – 7:00 PM
Oracle Corporation
6031 Connection Drive
Room 900
Irving, TX

…

There are a number of resources available to help get you up and running with MySQL Cluster so that you can start experimenting – including the quick start guides from the download page but what happens when you get further down the line and need to get the best performance from your Cluster? One useful source is the Guide to Optimizing Performance of the MySQL Cluster Database which covers how best to configure MySQL Cluster as well as what you should be doing with your application and schema to get the best performance.

Any feedback on this white paper would be greatly appreciated – whether it be a recommendation that you found gave good results, something that didn’t work or a killer tip that we missed out.

I’ll be presenting on/demoing MySQL Cluster 7.2 at this free breakfast seminar in Oracle’s London office on 25th April – starting with coffee at 9:00 and ending with lunch at 13:00 (quite a generous take on “breakfast”!). Space is limited and so if you would like to attend then register early here.

As well as MySQL Cluster there will be …