Microsoft Corp has sent beta versions of its long-awaited Wolfpack phase 1 clustering code (CI No 2,916) to 360 of its customers over the holidays, while keeping quiet about how much it will cost once it’s finally released, probably with a name like Cluster Server, hears ClieNT Server News. Gold code is promised sometime during this half year. A total of 160 end-users and 200 vendors got Intel and Alpha versions of Wolfpack and documentation that, as specified for phase 1, supports only hot failover and dual-server configurations. Multi-server clusters are scheduled for early 1998. Application sharing, which lets multiple servers combine their power – the ultimate value of clustering – isn’t in the cards until Wolfpack phase 2, which looks to be a late ‘1998 or 1999 product. A Wolfpack-enhanced version of what will be Sequel Server 7.0, code named Sphinx, is scheduled to be in beta test by June, as is a Wolfpack-enhanced release of Microsoft Exchange. The initial Wolfpack supports active-active configurations, which means both servers in a Wolfpack cluster can be on line running the same application, a more cost-efficient solution than simply having a hot standby server sitting doing nothing. If one server crashes, the other one picks up the load. As an unexpected nicety, Wolfpack also supports the failover of individual applications. That means that if, say, only one of several applications running on a server crashes, its server-mate only takes over the load for that application. The alternative would be to shut down all applications on the partially failed server. Wolfpack pieces include a cluster services module, a cluster communications services module with a communications manager, an administrator’s console that runs on NT Server or Workstation, and a set of application programming interfaces to access Wolfpack services. Besides the inevitable bugs that are sure to emerge from the beta, Microsoft has still got a bit of tuning to do. It recommends that each server in a cluster has at least 32Mb of RAM to run the beta. Other hardware requirements include shared SCSI storage with a dual SCSI initiator. Wolfpack program managers said last week that any well-behaved NT server application will work with Wolfpack phase 1 without modification. The definition of well-behaved is quite specific. It means the application keeps a consistent state on a disk drive and that the client side of an application can handle pauses in service, that is it sits and waits when a server isn’t available rather than shutting down. For the non-technical, that means the cursor arrow changes to a little hourglass. The Wolfpack-enhanced versions of Exchange and SQL Server will go one step further. By designing a server to be cluster aware it will restart faster, but that’s a nicety rather than a requirement. Once Wolfpack phase 2 comes, software vendors will have to tinker with their code to take advantage of load balancing when applications are shared by multiple servers.
Content from our partners
