Clustering and Storage / High Availability - Matthias Kranz and Jan Wildeboar

With my last session of the conference I decided to throw myself into the deep end completely and attended a hard core Red Hat session. I can see I really am going to have to work on my Red Hat skills quite a lot before doing this again, but anyway here are some points that I have picked up either from this session and from various conversations throughout the conference.

Red Hat Enterprise 5, the next release, is likely to include some substantial improvements.

iSCSI : low cost enterprise SAN connectivity
NFSv4
LVM2 : to include cluster wide snapshots

Application failover is possible when the correct start, stop and status scripts are available for the software. Some other features such as Membership, I/O Fencing, Lock Management and Heartbeats were discussed. I can imagine what some of these are when relating them to the JBoss clustering approach, but I was unable to follow the specifics. Two things which I did pick up on were STONITH (Shoot The Other Node In The Head?) and Lock Management.

STONITH is basically support for management cards that allow machines to be rebooted remotely. This is a well developed aspect of Red Hat which a member of the audience asked about.

Lock Management in clustered environments was previously made possible by a single lock manager. This has now been re-engineered so that each node has its own lock manager (DLM - Distributed Lock Management). This feature is new with Cluster Suite v4 and has brought enormous performance improvements.

The latest version of the Cluster Suite and Global File System have been shown to scale to 300 nodes in testing, but Red Hat are looking for a customer with a larger network to prove that it can scale beyond this.

The Global File System will now support 16TB on 32 bit systems, and 8EB on 64 bit systems.

Red Hat have had their Virtualization software on display at their stand. Apparently all the DVDs they wanted to bring are lost in transit somewhere so it looks like a download will be necessary to try this out for myself. They took great please in launching and destroying a Windows Vista virtual machine on the demonstration system. Virtualization support is, or will be, available in the Fedora distribution, meaning it's free for everyone and not just a part of the Enterprise suite.

The intent with future releases of Red Hat is to be able to replicate entire memory spaces from machine to machine, making it possible to provide fault tolerance for legacy systems far more easily. I'm not sure what kind of timescales may be on this, it sounds quite ambitious.

In conclusion, I needed a coffee badly.