IBM Z Server: Best In Class For Availability – Does Form Factor Matter?

A recent ITIC 2017 Global Server Hardware and Server OS Reliability Survey classified the IBM Z server as delivering the highest levels of reliability/uptime, delivering ~8 Seconds or less of unplanned downtime per month.  This was the 9th consecutive year that such a statistic had been recorded for the IBM Z Mainframe platform.  This compares to ~3 Minutes of unplanned downtime per month for several other specialized server technologies, including IBM POWER, Cisco UCS and HP Integrity Superdome via the Linux Operating System.  Clearly, unplanned server downtime is undesirable and costly, impacting the bottom line of the business.  Industry Analysts state that ~80% of global business require 99.99% uptime, equating to ~52.5 Minutes downtime per year or ~8.66 Seconds per day.  In theory, only the IBM Z Mainframe platform exceeds this availability requirement, while IBM POWER, Cisco UCS and HP Integrity Superdome deliver borderline 99.99% availability capability.  The IBM Mainframe is classified as a mission-critical resource in 92 of the top 100 global banks, 23 of the top 25 USA based retailers, all 10 of the top 10 global insurance companies and 23 of the top 25 largest airlines globally…

The requirement for ever increasing amounts of corporate compute power is without doubt, satisfying the processing of ever increasing amounts of data, created from digital sources, including Cloud, Mobile and Social, requiring near real-time analytics to deliver meaningful information from these oceans of data.  Some organizations select x86 server technology to deliver this computing power requirement, either in their own Data Centre or via a 3rd party Cloud Provider.  However, with unplanned downtime characteristics that don’t meet the seeming de facto 99.99% uptime availability metric, can the growth in x86 server technology continue?  From many perspectives, Reliability, Availability & Serviceability (RAS), Data Security via Pervasive Encryption and best-in-class Performance and Scalability, you might think that the IBM Z Mainframe would be the platform of choice?  For whatever reason, this is not always the case!  Maybe we need to look at recent developments and trends in the compute power delivery market and second guess what might happen in the future…

Significant Cloud providers deliver vast amounts of computing power and associated resources, evolving their business models accordingly.  Such business models have many challenges, primarily uptime and data security related, convincing their prospective customers to migrate their workloads from traditional internal Data Centres, into these massive rack provisioned infrastructures.  Recently Google has evolved from using Intel as its primary supplier for Data Centre CPU chips, including CPU chips from IBM and other semiconductor rivals.

In April 2016, Google declared it had ported its online services to the IBM POWER CPU chip and that its toolchain could output code for Intel x86, IBM POWER and 64-bit ARM cores at the flip of a command-line switch.  As part of the OpenPOWER and Open Compute Project (OCP) initiatives, Google, IBM and Rackspace are collaborating to develop an open server specification based on the IBM POWER9 architecture.  The OCP Rack & Power Project will dictate the size and shape or form factor for housing these industry standard rack infrastructures.  What does this mean for the IBM Z server form factor?

Traditionally and over the last decade or more, IBM has utilized the 24 Inch rack form factor for the IBM Z Mainframe and Enterprise Class POWER Systems.  Of course, this is a different form factor to the industry standard 19 Inch rack, which finally became the de facto standard for the ubiquitous blade server.  Unfortunately there was no tangible standard for a 19 Inch rack, generating power, cooling and other issues.  Hence the evolution of the OCP Rack & Power Standard, codenamed Open Rack.  Google and Facebook have recently collaborated to evolve the Open Rack Standard V2.0, based upon an external 21 Inch rack Form factor, accommodating the de facto 19 Inch rack mounted equipment.

How do these recent developments influence the IBM Z platform?  If you’re the ubiquitous global CIO, knowing your organizations requires 99.99%+ uptime, delivering continuous business application change via DevOps, safeguarding corporate data with intelligent and system wide encryption, perhaps you still view the IBM Z Mainframe as a proprietary server with its own form factor?

As IBM have already demonstrated with their OpenPOWER offering, collaborating with Google and Rackspace, their 24 Inch rack approach can be evolved, becoming just another CPU chip in a Cloud (E.g. IaaS, Paas) service provider environment.  Maybe the final evolution step for the IBM Z Mainframe is evolving its form factor to a ubiquitous 19 Inch rack format?  The intelligent and clearly defined approach of the Open Rack Standard makes sense and if IBM could deliver an IBM Z Server in such a format, it just becomes another CPU chip in the ubiquitous Cloud (E.g. IaaS, Paas) service provider environment.  This might be the final piece of the jigsaw for today’s CIO as their approach to procuring compute power might be based solely upon the uptime and data security metrics.  For those organizations requiring in excess of 99.99% uptime and fully compliant security, there only seems to be one choice, the IBM Z Mainframe CPU chip technology, which has been running Linux workloads since 2000!

IFL – A Cost Efficient zSeries Platform?

In September 2000, IBM introduced the Integrated Facility for Linux (IFL) processor, a specialty engine for and some might say dedicated to running the Linux Operating System.  At the time of this announcement, companion software named S/390 Virtual Image Facility for Linux was introduced to assist in the rapid deployment of IFL configurations, especially for non-Mainframe personnel.  However, this product was quickly discontinued, in favour of the standard z/VM Operating System, which is not difficult to learn and can accommodate hundreds if not thousands of zLinux images.

Today, the IFL is still a processor dedicated to Linux workloads on IBM System z servers.  The IFL is supported by z/VM virtualization and the Linux operating system.  The IFL cannot run other IBM operating systems.  The competitively priced IFL processor is a CPU capacity enabler, exclusively for Linux workloads.  Linux deployment (I.E. SUSE & Red Hat) on IFL’s can reduce expenses in the areas of operational efforts, energy, floor space and especially software.

The IFL provides the following functions and benefits:

  • The IBM Enterprise Linux Server is a dedicated System z Linux server, comprised of only IFL processors
  • No additional IBM software charges for traditional (E.g. z/OS, CICS, DB2, WebSphere, et al) environment
  • Performance improvement for Linux workloads with each successive generation of IFL and System z technology
  • Linux workload on the IFL does not result in increased IBM software charges for traditional System z operating systems and middleware
  • Same functionality as a General Purpose processor on a System z server
  • HiperSockets can be used for communication between Linux images, or Linux and other operating system images on the same System z system
  • z/VM virtualization and most IBM Linux middleware products, plus most vendor software products are priced per processor (core) according to the System z IBM International Program License Agreement (IPLA).  IPLA products have a one-time-charge (OTC) and an annual (optional) maintenance charge, called Subscription & Support
  • Supported by the current z/VM virtualization and IBM Wave for z/VM software versions
  • Always a full capacity processor, independent of the capacity of the other processors in the server
  • Orderable as a System z hardware feature. The number of orderable IFL features varies by the server model and configuration
  • Designed to operate asynchronously with other General Purpose processors
  • Managed by PR/SM in logical partition with dedicated or shared processors. The implementation of an IFL requires a Logical Partition (LPAR) definition, where following normal LPAR activation procedure, LPAR defined with an IFL cannot be shared with a general purpose processor.

There will always be the debate as to which processor and associated server type (E.g. x86, POWER, SPARC) is the most cost efficient, but there is no doubt that the ability to accommodate hundreds if not thousands of zLinux instances in one zServer environmental (E.g. Power, Cooling, Floor Space, et al) friendly footprint, with software pricing per core is worthy of consideration.

Adoption for zLinux has been steady and especially in the emerging territories where it’s not unusual for zSeries deployments to be totally zLinux (I.E. IBM Enterprise Linux Server) based.  Moreover, the majority of large and traditional IBM Mainframe users (I.E. z/OS) have installed at least one IFL, if only to evaluate the z/VM and zLinux offering.  Many have deployed the IFL and associated zLinux solution for business requirements.

Therefore, if one of the major cost benefit features of IFL is optimized software costs; can the IFL processor be considered for other workloads, originating from the traditional zSeries (I.E. z/OS) environments?

Proximal Systems Corporation (PSC) is a company with a solution that transparently offloads data processing from IBM Mainframes to Distributed Systems, with an objective of reducing software cost, while maintaining or improving performance.  The company name is derived from the concept of bringing disparate computing systems into close proximity, functionally speaking, providing totally seamless and transparent interoperability.  The result is a unified computing complex within which various tasks can be easily migrated between systems to their most cost efficient operating environment, while still being able to interoperate as if they were all hosted together on the same system.

The PSC Proxy Coupling Technology allows for a CPU orientated task to be offloaded from one system to another by means of an associated proxy task, which has an identical interface as the task to be offloaded, but delegates the majority of the processing to an offloaded task on another system.  The primary objective of this function are for the cost savings and/or performance improvements that might be delivered by migrating tasks to systems that are able to execute those tasks more efficiently.

The fact that the proxy task maintains the same interface as the application being replaced is crucial; as many past Mainframe migration projects have failed due to insurmountable interoperability problems between the Mainframe and Distributed Systems servers (I.E. Windows, Linux, UNIX, et al).  Proxy Coupling Technology offers a solution to this long-standing challenge.  In theory, this allows for the transparent offload of a traditional z/OS workload (E.g. Sort) from General Purpose (GP) processors, to a less expensive (E.g. IFL) alternative…

In the first instance, the Proxy Coupling Technology offloads General Purpose CPU workload associated with the z/OS sort (I.E. CA Sort, DFSORT, Syncsort) function, to another platform (E.g. IFL).  For IFL based implementations, HyperScokets are utilized to transfer data at memory speeds from the z/OS task to zLinux on the IFL, where the sort operation completes, while the resulting z/OS task and associated data are maintained, as per normal.  From an IFL viewpoint, Ahlsort software performs the sort operation, being a sort solution that maintains compatibility with the majority of z/OS sort function (I.E. Control Card Syntax).  Therefore, this is a transparent implementation, where the only consideration is how much CPU capacity is required for the offload function (E.g. IFL, x86).  The benefits are reduced z/OS MSU usage for the sort function, which can be quite significant, as most business data (E.g. Database Offloads, Customer Orientated, et al) is sorted on a daily if not more frequent basis.

Just as IBM introduced the zAAP on zIIP capability, which allowed some customers to more easily justify a specialty engine (I.E. zIIP), combining workloads to exploit the full capability of the specialty engine; in theory the same ethos applies with the Proxy Coupling Technology.  For the avoidance of doubt, workloads that can be processed on an IFL, such as z/OS sort tasks, can assist in delivering higher Return On Investment (ROI) levels for the IFL, for example:

  • Reduced z/OS WLC MSU usage (I.E. Sort function offload) and associated software costs savings
  • IFL processors run at Full Speed and do not add to traditional workload (I.E. z/OS) software costs
  • Utilize any spare IFL CPU resource not used, releasing General Purpose CPU resource for other work

In conclusion, the Proxy Coupling Technology offers a proposition that is similar to the IBM philosophy of reducing z/OS software costs via specialty engines.  Seemingly to date, primarily only the zIIP and zAAP specialty engines were available to optimize CPU usage for z/OS workloads.  Offloading CPU cycles and thus MSU workload to IFL makes sense, utilizing a cost efficient and indeed a full power CPU engine, where for cost reasons, maybe the majority of z/OS customers don’t deploy the “highest” derivative of General Purpose CPU engine available to them.  On the face of it, the realm of possibility exists for other workloads to benefit from z/OS to IFL CPU offload, following sort, which seems to make sense as the first workload to utilize this solution.