Mainframe Vs Mid-Tier Computing


I have been in Technology for more than 25 years. I have supported systems on both mainframe and midtier platforms. I’m often questioned as to which platform is better. To be open and honest, I’m a mainframe person at heart. I grew up on the mainframe and feel more comfortable working on mainframe systems. But as I’ve progressed into management, I’ve had to take a more open look at mid-tier systems and become more cynical of the mainframe.

Mid-tier systems have grown significantly over the years. The hardware platform has become much more dependable and cost effective solution.

Let’s review a couple of trends in technology:

  • Linux has taken the world by storm. This operating system has claimed its place in many mainstream I.T. shops. The company that I work at has openly embraced Linux. It has almost completely replaced the UNIX/AIX/SUN environments that have been in place. One big thing to note about Linux is that is really is hardware independent. Linux can even run on the mainframe.
  • Virtualization has been the rage in Technology. Virtualization has enabled mid-tier solutions to become much more cost effective by increasing the overall utilization of hardware. But virtualization is not new. Virtualization has been a mainframe stronghold for many years. Work Load Management (WLM) has been around the mainframe for what seems like forever. The mainframe has excelled in balancing a variety of workloads. Adding virtualization to the mid-tier environment has enabled the mid-tier systems to function much more like a mainframe.

So if Linux can run anywhere and virtualization makes mid-tier seem like a mainframe, why use a mainframe?

There are still many functions that the mainframe still excels at. The mainframe’s WLM still far exceeds the capabilities of mid-tier servers. Mid-tier virtualization is much better at horizontal scaling. The mainframe does vertical scaling significantly better. Large volume transactions that utilize high input output processing are better suited for the mainframe. High computing processes are better suited for the mid-tier.

There are probably a lot more packaged software solutions available for the distributed world. But the reliability, availability and scalability of the mainframe are still incredible.

In the mainframe world, parallel sysplex will enable a group of mainframes to operate as though they are one machine. This provides an organization with a lot of options as to how they wish to deploy their technology. These mainframes do not even need to be located near each other. Geographically Dispersed Parallel Sysplex (GDPS) would enable an organization to run multiple data centers and have them all look like one to the customer.

So which is better? It really depends upon your workload and the amount of existing work that you may have on the mainframe today. If you were starting from scratch, I’d probably start with servers. But if I had a large investment in the mainframe, I’d look to keep the mainframe and exploit servers where it makes the most sense. I’d use the servers for presentation and application layers. The mainframe is the best and safest platform for data management.

Decide for yourself which better fits your needs and your budget.

Linux is probably one of the biggest improvements that have come down the road. The Linux operating system takes many of the advantages of UNIX and improves it. Linux is able to run on just about any platform – including the mainframe.


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