Many years ago in 1995 or 1996 the mainstream IT community view was that Mainframes are doomed and will be replaced by cheaper and more flexible Client/Server technology. Xephon, published a white paper titled: Mainframe and the Dinosaurus Myth. The thesis presented in this paper was that Mainframe is cheaper than Client/Server due to high maintenance costs of distributed Client/Server.
The term maintenance costs includes higher support costs for Client/Server. After few years of experiencing Client/Server limitations Xephon unpopular theory was supported, at least as far as large enterprises were concerned.
More than decade after the Dinosaurus myth, one surprising finding in STKI Israeli Market Survey was related to Mainframe. According to the survey 40% of Israeli IT budgets are allocated to Mainframes. If you search for Mainframe in the conference presentation slides, you will not find any occurrence of it. This finding was mentioned byExplaining the results by relatively high software costs of Mainframes is not a good enough explanation: Mainframes still play important role in IT systems.
Pini Cohen during his presentation on Israeli Infrastructure Trends.
This is not the only quote referring to Mainframe important role in current IT systems of the
SOA and distributed systems age. In a presentation of DataDirect's Shadow RTE Mainframe Service Bus (Mainframe dedicated Enterprise Service Bus integrating it with services and consumers on other platforms) the company provides the following information:
- Greater than 60% of the world "system of record" data on mainframes
- More than 450 of Fortune 500 rely upon mainframes
- More commercial transactions processed on mainframe than any other platform
Even if someone will argue that the information is not accurate or not updated it is at least a rough estimation.
However, STKI's finding is still surprising because of the Israeli market characteristics: relatively few Large Enterprises and higher market share for Microsoft and Oracle in comparison to many other countries.
Mainframes are frequently used in the
USA and the Western Europe markets in Banking, Credit Cards, Insurance, Telco, Government and Utilities sectors (I am excluding the military sector because part of the information is confidential or concealed).
Some successful SOA implementations are based on exposing Mainframe services to consumers in other platforms especially self-service usage via internet or other channels. Two interesting SOA Case Studies in the Telco sector exposing Mainframe Services are Verizon and Sprint-Nextel.Similarly to the Banking industry in
- Insurance – The only VSE/VM site in
decided to migrate to UNIX. There are many UNIX based sites and some AS400 Mainframe sites and no IBM's z/OS Israel
operating system sites
- Telco – Most companies were established few years ago, so the prevailing platforms are UNIX and Windows hosting Oracle, Microsoft BEA, IBM WebSphere based applications. The only exception is Bezeq, the largest company which was a governmental monopoly still deploying a z/OS based system. If a Postal services company will be included in the Telco market you can add another z/OS installation: The banking services of the Israeli Post company.
- Public Sector –Few IBM Mainframe installations but relatively to other countries larger base of HP's OpenVMS. Many applications are gradually replaced by SAP on Windows servers.
The Dinosaur Myth is only a myth: for large and complex enterprises the Mainframe (especially IBM z systems under z/Os operating system), will be valuable for long term due to Robustness, high Reliability, high Availability and incomparable Scalability (e.g. CICS Transactions Monitor with ten thousands or twenty thousands users).
The hardware platform innovations include dedicated processors for Java and Linux on Mainframe. We should wait and see if the new announced z10 computers family including quad-core processes, will fulfill its promises described as" Data Center in a Box" will be realized and support the Green IT trend.
During SOA implementation there are three mainframe strategies:
- Mainframe Replacement
- Mainframe Enablement – non-invasive approach for exposing Mainframe Services (usually through Web Services)
- Mainframe Rejuvenation – Leveraging Mainframe as a full participant in SOA architecture together with other platforms.
Rather than analyzing these three alternatives, I recommend reading Zapthink's White Paper The Mainframe as a First Class SOA Participant written by ZapThink's analyst Jason Bloomberg.Notice that Mainframes are not only Service Providers they could act as Service Consumers and as Enterprise Service Bus platform.