Since the Open Software Foundation’s choice of technology for its distributed Computing Environment was revealed at the end of April, a war of words has been going on within the industry between the Alternative Unix Club and supporters of rival methods for doing distributed computing. Open Software Foundation officials, Transarc Corp and the Apollo arm of Hewlett-Packard Co have been talking to Unigram.X in an attempt to dispel the negative vibes thrown up around the – still nameless – Environment by some sections of the industry, and discuss what they regard as the technical advantages of the technology over other distributed computing environments, such as Sun Microsystems’ Open Network Computing Platform. Jonathan Gossels, Open Software Foundation business area manager responsible for the selection process, sees the Environment as addressing the fundamental problem with Unix – that it doesn’t interact with the real world, with proprietary operating systems that are already out there. Furthermore each of the proponents shares a central belief that without the benefits that the Environment brings, Unix will come up short. Benefits they claim are in areas of performance and security – and they warn that promulgating a standard, [Sun’s Open Network Computing], is no good if the standard is flawed. Although they accept that the Network File System element of Open Network Computing – by virtue of its sheer installed base, which numbers upwards of 800,000 is something of a de facto standard in the market, they believe that Distributed Computing Environment offers additional functionality in areas where Open Network Computing comes up short.
Ambiguity
Getting down to business, the Transarc people – Alfred Spector and Philip Lehman – tried to clear up some of the ambiguity that has surrounded the relationship between the firm’s Andrew File System – part of Distributed Computing Environment – and Sun’s Network File System ever since the the Open Software Foundation’s announcement. They say, contrary to some of what has been written about Distributed Computing Environment, that the two can talk to each other back and forth as well as accessing data across each other, indeed at the launch, the Open Software Foundation demonstrated a server running Distributed Computing Environment communicating via Open Network Computing with Sun Microsystems’ SunOS operating system. Important questions have also been raised about Distributed Computing Environment’s ability to integrate personal computers and the 25m Novell nodes out there – not to mention those of Banyan or 3Com. The officials firmly maintain that networking technology such as Portable NetWare should run comfortably on top of the Distributed Computing Environment file system with no problem, because the Environment uses precise Unix semantics that will map on to such network schemas. Indeed Alfred Spector says that Transarc will work with Novell if there are any problems. At present personal computer users running MS-DOS and OS/2 have two methods of access to Distributed Computing Environment – both of which are now X/Open standards.
By William Fellows
Firstly Sun Microsystems’ PC-NFS, public domain software, and secondly Lan Manager/X, the Microsoft Hewlett-Packard technology – both of which are present within Distributed Computing Environment. However during the discussions it was revealed that these methods look set to be superseded, as the Open Software Foundation says it is currently working with several companies to port Distributed Computing Environment to personal computers. On the whole, the group believes that while Open Network Computing is effective, it has certain weaknesses and limitations where security, permissions, record support and consistency are concerned, as well as program anomalies – NSF 2.0 is good for its time, but is now seriously outdated, said Transarc’s Phil Lehman. As well as embracing consistent caching, whereby the system knows when data is up-to-date without having to access the network on each occasion for verification, Sp
ector claims that in comparison with Open Network Computing, which typically may support between 10 and 30 clients, version 4.0 of its Andrew File System, embedded in Distributed Computing Environment, will support up to three times this number per server on typical applications, providing far superior performance. Another advantage claimed for Distributed Computing Environment is that systems administrators do not have to stop users from working when doing a back-up – these tasks can be performed while the system is being used, and that because of the way that the file system is timed and cloned during this process, a user can restore a particular view of the file system – perhaps the one that was being used two weeks previously. Goss-els claims an average recovery time of two minutes for Distributed Computing Environment when a system is down no matter how much disk capacity is configured, as opposed to the half an hour or so that a similar Open Network Computing-based system would require. In addition the Open Software Foundation claims that Distributed Computing Environment’s just once architecture means that no duplication of data will take place during any transaction – even for instance in the event of a banking system going down – because the Andrew File System operates in conjunction with the Hewlett-Packard Apollo-DEC enhanced Network Computing System Remote Procedure Call, which is claimed to be semantically coherent. As far as the transport layer is concerned, the Foundation claims that because Sun’s Remote Procedure Call is not transport-independent, application developers have to work with a target environment – such as TCP/IP. While Distributed Computing Environment is claimed to be transport transparent, it currently works only with UDP/IP and Xerox Corp’s XNS transport protocols, though it says TCP/IP and DECnet support will be added, and Open Systems Interconnection will follow when guidelines are formally defined by International Standards Organisation.
Size penalty
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The Open Software Foundation is also keen to get the Environment interacting with databases, and says that Informix, Ingres and Sybase have already endorsed the technology. A future database and interoperability Request for Technology is planned to ensure that databases will be interoperable across the Software Foundation technology. One aspect on which the Foundation is touchy is the size of its creation, which will not be disclosed until after the launch – indeed the Open Software Foundation even claims it has not sized it yet. However Gossels admits that because Distributed Computing Environment does a lot of things, there is a price to pay – in terms of size. As far as takers go, Gossels says he is negotiating with most of the major players – including Unix International companies – and that initial responses have been tremendous. For all Gossel’s protestations to the contrary, there is nevertheless much bitterness – and fury – at the Open Software Foundation’s decision within the Sun supporters camp. Gossels is desperately trying to pour oil on these stormy waters. He claims that meetings are being held with Sun to sort out interoperability on a technical level and reckons the industry will see through what is effectively sour grapes.
