The buzz of the week is all about books. The second edition of High Performance MySQL has just hit the shelves. In addition to being a complete rewrite of the first edition, this is a sort of community book, where the authors gathered together the official tools and the ones available in the community to explain how to make MySQL fly. Many topics were submitted for public discussion. It is also the first time that an author has explained in public how to write it. The other second edition is a reprint of the MySQL Cluster certification guide. Noticed anything peculiar in the cover? Yes! It's a Sun book. This is actually the very first book to be published through Sun's new print-on-demand partner, Vervanté. In other words, Sun's first Vervanté book is a book on MySQL!

	Contrary to mounting rumors, MySQL is not closing or removing MySQL Cluster. The reason for the cluster applications being missing in the latest 5.1 binaries is a split release model, as Kaj Arnö explains. The almost simultaneous announcement of Cluster 6.2 release is a confirmation that the Cluster is alive and kicking.
To reinforce the Cluster buzz, another blogging entity has surfaced. The MySQL Telecom Team is mostly involved in Cluster technologies, although not exclusively.

Kedar has a blog on GlassFish cluster administration (domain, DAS, Node Agents, Instances, ...). This should come handy to people looking at understanding when synchronisation actually happen with the DAS (Domain Administration Server) which is where the centralized repository sits. We often claim to have BEA's features at JBoss' price. This centralized cluster management is certainly one such feature.

Most GlassFish subprojects (Grizzly, Metro, Woodstock, HK2, Jersey, mq, Mojarra, ...) can be used independently from the application server. Project Shoal is no exception. This Group Management Service used by GlassFish clustering can also be applied to other use-cases.

Community members Juan Pedro Danculovic and Diego Naya have a nice article over on java.net covering in a single place most of the Shoal features. It goes into the definition of all the basic terms such as Group, Member, Member Token, Spectator, Core, Group Management Service, Components, and Signals. The article also covers how to integrate your own code into the clustering infrastructure (not only for Java EE applications, but SE applications too). Given the artifact's size (JARs are less than 2MB), together with a stripped-down GlassFish v3, the possibilities become very interesting.

Previous Shoal resources include:
•  Previous Shoal posts
•  Other introductory Shoal article
•  GlassFish podcast interview about GlassFish Clustering and Shoal

In this third episode of the GlassFish Podcast, HA engineering lead Shreedhar Ganapathy discusses project Shoal and how it's applied to GlassFish clustering as a GMS (Group Management System) technology but also how it does in-memory replication to provide High Availability (depending on the profile used). If you're interested in the max number of nodes in a cluster, buddy replication, recovery failure notification, sticky load-balancing, availability level, or distributed state cache, this interview gets into all of these. It also tries to go from first steps to setup the cluster to tips on running and managing it effectively. Finally it touches on what's next for clustering in GlassFish in the next 18 months.

This is a longer podcast that the earlier two (40 minutes). Feedback is welcome about what you think is the optimal duration (although I suspect this varies depending on one's commute).

GlassFish V2 is adding the remaining Enterprise-Quality features into the Open Source Project GlassFish. For Milestone 2 that means improved clustering installation and administration, and these revolve around the concept of a Domain. Two good overviews of Domains are Shreedhar's recent entry and Kedar's earlier blog. More TA entries on the subject are here. Cluster installation has also been incorporated into the quickstart guide. Finally, the GlassFish V2 Architecture Page has more details.