Client-server computing, downsizing, migrating to personal computers and file servers. All wonderfully exciting, wonderfully hyped concepts, and wonderfully well equipped to send a data processing manager from the room, screaming. And that’s not just the stereotypical manager who thinks that personal computers are the spawn of hell. There are real problems here. Compared with a big mainframe in a controlled environment surrounded by a team of expert programmers, building a personal computer-based client-server system is inherently more complex. Programmers have to learn new skills, forego tried and tested mainframe application environments and worry about making their code cope with failures in the client, server or network. Yet, ranged against this hassle is the ‘bangs per buck’ argument: the fact that for the same amount of money, more MIPSage is available on personal computers than on mainframes. On top, there is the flexibility of distributed systems and the conceptual appeal of co-operative processing. The network is the computer, to coin Sun Microsystem Inc’s rather optimistic sales slogan. Just arrived in Europe is San Jose, California-based Cooperative Solutions Inc’s bearing its challenging Ellipse.
Nastier aspects
The company is the latest to catch Novell Inc’s eye, pleasing it sufficiently to win an investment from the Provo, Utah NetWare onlie begetter (CI No 1,834). Ellipse is a combined development and run-time system designed to help build transaction processing applications on local area network-based workstations and servers. The concept is simple, and sounds almost too good to be true. The Ellipse/DE development environment enables programmers to ignore the fact that the application they are writing is to be distributed. It is based on a series of graphical editors so that developers can slot together pre-fabricated transaction processing elements and call statements to produce their own object-oriented procedures. If a necessary function falls outside the scope of Ellipse’s competence, the programmer can call external bits of code. Moreover, since the finished procedures are stored in a central repository, many programmers can collaborate on a project – workgroup programming if you like. The average Cobol programmer can swiftly come to grips with Ellipse/DE, claims the company, and once the application writers have done their bit, it is time for Ellipse/PS – the production system – to take over. When the finished code is deployed, Ellipse/PS asks for a map of the available network hardware resources. This is used to partition the application intelligently, and allocate logical modules to a particular networked machine. Once it has distributed the application, Ellipse/PS handles the nastier aspects of running a distributed application – when a server goes down, or a cable gets kicked out. The company says that Ellipse/PS is inherently resilient to errors. If a server or network failure occurs, then the transaction is automatically backed out and, if possible, re-tried. If the problems continue, a message is flashed onto the user’s screen. This claimed robustness, which sets Ellipse apart from other tools, is central to its chances of success and it is no accident that the founders of Cooperative Solutions Inc were old hands at Tandem Computers Inc when they set up the firm in 1989. Between them, vice-president of research and development Kim Worsencroft, and chief executive Dennis McEvoy, clocked up 22 years with fault-tolerant manufacturer, with McEvoy co-authoring its Guardian operating system. If Cooperative is right, then the potential market is huge.
By Chris Rose
Only potentially huge mind you. A forthcoming report from London-based consultancy Ovum Ltd says that before users will put their faith in personal computer local area networks, they will demand a number of things. Among these are application tools that both run and generate applications for the client server environment. Particular requirements include something that will facilitate the partitioning of the application into differ
ent client and server processes, debug applications across different environments, support high-level graphic interfaces and hide the the low-level intricacies of the client interface from the programmer. Other prerequisites include management tools, especially for configuration management, software distribution and tracking and most importantly, for systems and network management. More standardisation is needed, with open standards for distributed computing which incorporates personal computers, servers and mainframes. Ellipse clears the first barrier and helps with the second, but stumbles at the third its systems for inter-process communication are proprietary, although in her defence, Ms Worsencroft has pointed out that when the company first started development two years ago, things like the Open Software Foundation’s Distributed Computing Environment were mere twinkles in the industry’s eye. Similarly, she avoided the use of Sun’s remote procedure calls or Hewlett-Packard Co’s Network Computing System because of inefficiencies when moving large chunks of data across the network. Other shortcomings? An article in US magazine Datamation says that Ellipse doesn’t support IBM’s LU6.2 protocol, so programmers need to write their own modules if they need to get into DB2. Second, the drive to portability leads, almost inevitably, to a lowest common denominator approach, and clever features like Sybase Inc’s binary large objects go unsupported. The third question regards job size – Ellipse applications can support around 20 active users and database size is limited to around 400Mb of disk space. Some of these limitations will be disappear in the Unix and OS/2 2.0 versions, and apart from those three question marks, no one seems to have come up with any serious objections. The Ellipse development environment comprises OS/2-based client and server, while the production system is Windows or OS/2. The Server runs OS/2 but support for Unix is due later this year with a NetWare Loadable Module and Microsoft Corp NT following later. The communication services include LAN Manager, NetWare, Vines, LAN Server and TCP/IP, and the database management systems are Sybase and Microsoft SQL server with Oracle support due next, followed by IBM’s Database Manager. Before dashing out, cheque-book in hand, it is worth mentioning that Cooperative Solutions does have competitors.
Primrose
San Francisco-based Tesseract Corp launched its fragrantly-named Primrose system in the US at the end of April. Primrose takes the computer is the network theme even further than Ellipse, according to Tesseract’s director of software marketing, Dan Easterlin. Whereas Ellipse is firmly based on the client-server model, Primrose arranges things using a more equitable peer-to-peer arrangement. Moreover, the Tesseract product does not partition the application once only, but every time the application is run, passing pieces of executable code across the network. The most significant difference between the two is that while Ellipse is essentially limited to developing transaction processing applications, Primrose is a more open-ended development environment. The result of the peer-to-peer and open-ended approach is a product, says Easterlin, better suited than Ellipse for writing Online Complex Processing applications where a lot of sophisticated data manipulation is carried out before the result is presented to the user. Finally Oakland, California-based Forte Software Inc is hoping to have its tool in beta test by the autumn (CI No 1,666). It is giving few details, but indications are that it will challenge Tesseract and Co-operative Solutions head-on. Should the tools live up to their promise, then the local area network may be used in ways that hitherto have been only theoretical. Mainframes of the world beware.
