Shareplex gains converts in quest for clustered 3000s
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Shareplex gains converts in quest for clustered 3000s

HP builds High Availability program bridges with distributed computing solution spanning systems

HP has shifted its emphasis on single system performance for HP 3000s this year by leaning harder on its Shareplex solution. That's because officials at the HP 3000 division (CSY) say companies that buy today's high-end HP 3000s are managing growth that outstrips the scalability of any single system, regardless of manufacturer or design. HP is turning to Shareplex/iX -- marketed as NetBase by its creator, Quest Software -- to guarantee the 3000's ability to meet processing needs at fast-growing companies. (The two product names are used interchangeably, even by customers who have one or the other installed).

First introduced in the early 1990s, Shareplex appears to be an idea whose time is coming, if judged by the comments from managers at sites where it's now serving. The software makes the resources of HP 3000s available to other HP 3000s on the network, a concept that has been called clustering since its introduction in the 1970s. HP and Quest like to say that customers no longer have a top-end limit in computing performance when they implement Shareplex. Quest points to the capability to bypass limits in concurrent users, tables and locking by distributing several applications to a front-end system that shares resources with other HP 3000s.

It's a fact of computing that any distributed solution will be more complex to manage than a centralized resource. The HP 3000 continues to maintain an edge over more trendy solutions like Unix and Windows NT for precisely that reason -- a single HP 3000 can serve more users effectively than those alternatives. Even HP recommends dedicating a Unix server to a single solution, while HP 3000s routinely host multiple applications.

However, customers are beginning to report the complexity in making this shared environment work with MPE/iX is a one-time productivity hit when using Shareplex, instead of an ongoing management drain like networked Unix systems. At the American United Life insurance company a pair of high-end HP 3000s have been linked via Shareplex/iX, and are delivering a whole computing capacity that's greater than the sum of its parts.

The shadow knows
Jack Snyder is manager of planning and technical support at the company headquartered in Indianapolis, Ind. American United Life manages pensions and 401K plans as well as 20 different mutual fund accounts with its HP 3000s, work that has to go on around the clock. Snyder said that the initial implementation of Shareplex was no cakewalk, but getting over that hurdle pays even more benefits as he adds HP 3000s to his cluster.

"There's a one-time hit getting it set up, but whether you're doing two or 20 machines, administration stays pretty stable," Snyder said. His company has two Series 995 systems, each with eight processors shadowing each other. Two years ago, Snyder set up his systems to work with Shareplex/iX, at first to handle the demands of running 1,000 sessions on each system daily and a half-million jobs a year through his scheduler.

By now the company's systems do bi-directional shadowing, each taking its turn at more than 140Gb of IMAGE/SQL databases. It's a little-used capability, according to Snyder, whose implementation lets a main application use five different databases divided into 10 groups, each group for a different company product line. Some master datasets reside on one system, and other masters are located on the other system. Each master is shadowed to the opposite HP 3000 to enhance reliability as well as availability.

"You try to use NetBase to protect yourself, and it's worked very well for us," Snyder said. "We had situations where a hardware failure on one machine let us get back up in 30 minutes and have the majority of our business still running -- instead of everybody being down for three or four hours."

Networked data access
American United Life uses Shareplex as much for data availability as for disaster recovery, Snyder said. The company uses the software as a way around a performance bottleneck. "We have a lot of programs that have to be able to access data from all of our database groups," he said. "I needed more than eight processors, but I had to be able to have access to all of the data."

With a 30 percent annual growth rate, the company has begun to outstrip HP's capability to scale the HP 3000 upward, Snyder said. "With [Shareplex] and the 64-bit chips, HP's got virtually unlimited power for us," he said. "We can either grow by adding processors or by adding boxes with Shareplex."

The Aberdeen Group rated the HP 3000's clustering one of the best in the industry in a survey three years ago, and Snyder agreed. "The HP 3000 is one of the more advanced systems out there," he said. "It just depends on how you use it. I looked at going to Unix, and I'd need three or four truckloads of T-500s to do the work I'm doing with these HP 3000s."

Still room to improve
With its growing customer base, Shareplex/iX and NetBase are bound to improve, as more experience in the field yields configuration savvy ready for those new to the solution. Snyder said Shareplex mandates more administration than nonclustered solutions, "but it's a lot less than I'd have to do on any other platform. I don't think it's unusually high. I was able to more than double my computing capability without doubling my administrative work."

It's a different type of administrative work, Snyder adds, since Shareplex and "NetBase sometimes keeps you a little more honest." The solution adheres closely to Posix conventions. That means when American United Life's programmers took advantage of undocumented features of Basic and COBOL, the features "weren't there in MPE/iX 5.0, and NetBase picked that up in many cases before the applications blew up." Snyder also said having "four of the best system managers in the country" working at American United Life "doesn't hurt when working with NetBase."

One of the advances HP hopes to offer as it pushes Shareplex/iX in the coming year is a better understanding of the software's capabilities. In addition to shadowing, disaster recovery and shared database access, Shareplex/NetBase can give access to IMAGE data from HP-UX, SCO, Unix, Sun and Windows clients. The Shareplex family also includes database replication capabilities for HP 3000 sites that use Oracle. This makes the software a good path to data warehouse implementations where the warehoused data can reside on HP 3000s.

The HP 3000 division considers the solution important enough to make it a key component of the Horizontal Growth Solution Team. HP is willing to admit that not all applications are suited for clustering, and the solution team is working to define guidelines that will identify which applications will benefit from horizontal growth.

Copyright 1997, The 3000 NewsWire. All rights reserved.