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-- by Tom Henderson
When it comes to clustering software, Microsoft Wolfpack is running off with all the headlines. Hardware makers are taking Wolfpack very seriously (see NT Enterprise Edition feature in this issue), but let's not forget two important factors: Wolfpack is still in beta, and it won't work with millions of NetWare servers that companies continue to rely on. With these shortcomings in mind, fault tolerance software from Novell and Vinca Corp. might be worth a look.
Novell's Systems Fault Tolerance (SFT) III technology lets you mirror memory, NLMs and system disks between two NetWare or IntranetWare servers. (IntranetWare is a rebranded NetWare 4.11 with integrated Web software.) With SFT III you can also mirror applications running in memory, such as Novell's GroupWise 5.x (you'll read more on GroupWise later in this column)
If a primary NetWare server crashes within an SFT III system, clients are transparently failed over to the secondary NetWare server-at least, most of the time. Unfortunately, transactions can be lost during the fail-over if your client and server applications aren't fully synchronized by your company's network administrators. Also, an application failure on your primary server can occasionally crash your secondary server (that is, what kills your primary system can be equally fatal to your backup system)
Still, an SFT III system is certainly more reliable than a single NetWare server. That's why hospitals, credit card call centers and newsrooms around the world use SFT III. If you'd like to use it, too, you'll need two Novell-certified 386-based servers or above, at least 16MB of RAM on each server, two Mirrored Server Link (MSL) communication adapters and cables, identical network adapters, and identical monitors and video adapters. SFT III costs $1,495 for two nodes supporting up to 100 users and $3,995 for two nodes with more than 100 users.
NT clusters today
Novell brings fault tolerance to your NetWare servers, but what about NT? One option is StandbyServer for NT from Vinca Corp. (http://www.vinca.com) of Orem, Utah. The software requires two servers running NT Server 3.5x or later, two dedicated network interface cards and network cabling. Unlike Novell's SFT III for NetWare, it does not require identical servers, and the backup NT server can be used for other services.
StandbyServer, also available for NetWare and OS/2, mirrors an entire filing system (or only portions of it, depending on your needs) of a primary server to a backup or standby server. The software does not, however, mirror the primary server's system information or system apps running in memory. In addition to mirroring, the standby machine is constantly monitoring the status of the primary server. If the primary server fails, it takes about a minute for all user account information and defined shares to be transferred to your standby server.
StandbyServer for NT ($3,499 per two-node cluster) is a good solution for fault tolerance, but products like the Microsoft Transaction Server (formerly code-named Viper) are still required if you want to guarantee transactional integrity in a fail-over system. In some configurations, you'll need to run the transaction monitor on a third server outside the StandbyServer cluster.
By contrast, Novell's SFT III has integrated transaction tracking, and Microsoft's Wolfpack-if you can wait for it-will likely ensure application transaction integrity by early 1998. Popular server software like Oracle7, SQL Server and SAP R/3 will need to be tweaked to support this feature. That work is already under way: Compaq and Tandem recently demonstrated SAP R/3 running in a Wolfpack cluster, and Microsoft is developing SQL Server 7.0 (code-named Sphinx; see NT Newstrends in this issue) with native Wolfpack cluster support.
You're probably wondering what will happen to StandbyServer for NT once Wolfpack arrives. Vinca says it's committed to supporting Wolfpack's APIs and will also offer a Wolfpack-compatible resource management feature in the very near future. That type of commitment should protect an investment in StandbyServer.
Clustering software isn't the only technology I've had my hands on lately; I've also been testing the latest e-mail software from Microsoft and Novell. I've already focused on Microsoft Exchange Server 5.0 (see NT Administrator, April), so here's some equal time for Novell GroupWise.
I recently took a long look at the latest GroupWise 5 release. I couldn't help but notice that its user interface closely resembles pieces of Microsoft Exchange, Outlook and Explorer. Or, maybe I should say Microsoft's products resemble GroupWise, since Novell's software came first. Although GroupWise is chained to Novell Directory Services (NDS), you can certainly add the groupware product (along with NetWare 4.x) to an otherwise homogeneous NT network. Novell also allows GroupWise post offices to be placed on either NT Server 3.51 or 4.0, or NetWare.
GroupWise 5 supports Microsoft's Telephony API (TAPI) as well as Novell's own Telephony Services API (TSAPI). My phone works with both, and dialing from GroupWise was incredibly simple. Road warriors may have more trouble with GroupWise's telephony services, however, since they'll likely need to change their user profiles when leaving the office.
Novell has paid particular attention to improving GroupWise's document management capabilities. GroupWise 5.0 now uses a library-type document check-in/check-out metaphor that's fairly easy to understand. The same folders that contain documents can also contain discussion groups.
Another improvement is Novell's new NetWare 32 client (required to run Novell's NWAdmin utility). I prefer it over Microsoft's client alternatives, except for a single curious bug: NetBEUI must be installed prior to installing the NetWare 32 client, otherwise it can't be used at all.
Strangely, GroupWise doesn't include Internet mail components (such as an SMTP gateway) in the box, but you can get them free from Novell if you purchase a GroupWise 5.x release before July 1. Like Exchange, it's still impossible to use third-party message storage platforms, or even decent RDBMSs, with GroupWise.
Even so, the Novell application is worth consideration if you're seeking a document-oriented groupware package without the overhead of Lotus Notes. And, if you're worried about fault tolerance, you can certainly run GroupWise in an SFT III network today, or a Wolfpack cluster tomorrow.
Contributing editor Tom Henderson is vice president of engineering for Indianapolis-based Unitel. Contact Tom in the "Enterprise Administrator" topic of WINDOWS Magazine's areas on America Online and CompuServe, or care of the editor at the addresses here.