zHyperLink: Just Another System z DASD I/O Function Enhancement?

Over the last several decades or so the IBM Mainframe platform has delivered several new technologies that have dramatically improved the performance of disk (DASD) I/O performance.  Specifically the deployment of ESCON as the introduction to Fibre Optical channels, followed by EMIF for channel sharing and reduced I/O protocol, superseded by FICON and most recently zHPF.  All of these technologies have allowed for ever larger amounts of data to be processed by the System z server and the adoption of Geographically Dispersed Parallel Sysplex (GDPS) implementations for business continuity reasons.  Ultimately mission critical data and decisions are facilitated by applications and sub-second response times for these transactions is expected.  Some might say that we’re always running to stand still from a performance perspective when implementing the latest System z technologies?

In reality, today’s 21st Century mission-critical application is not just capturing and storing customer data, it’s doing so much more, attempting to make informed business decisions for a richer customer experience!  Historically a customer transaction would be on a one-to-one basis (E.g. ask for a balance query), whereas today, said transaction might generate more data for the customer, potentially offering them a new or enhanced product.  In theory, this informed and intelligent transaction processing delivers a richer experience for the customer and potentially new revenue opportunities for the business.

For several years IBM have integrated the Cloud, Analytics, Mobile, Social & Security (CAMSS) initiative into their product offerings, recognising that a business transaction can originate from the cloud or a mobile device, potentially via a Social Media platform, require rich processing via real-time analytics, while requiring the highest levels of security.  Of course, one must draw one’s own conclusions, but maintaining sub-second or ultra-fast transaction response times, with this level of CAMSS complexity requires significant performance enhancements.  To deliver such ultra-fast response times requires the DASD I/O subsystem to maintain the highest levels of performance, aligned with the latest System z server platform…

In January 2017 IBM issued a Statement of Direction (SoD) and associated FAQ for their zHyperLink technology.  zHyperLink is a new short distance mainframe link technology designed for up to 10 times lower latency than zHPF.  zHyperLink is intended to accelerate DB2 for z/OS transaction processing and improve active log throughput.  IBM intends to deliver field upgradable support for zHyperLink on the existing IBM DS8880 storage subsystem.  zHyperLink technology is a new mainframe attach link.  It is the result of collaboration between DB2 for z/OS, the z/OS operating System, IBM System z servers and the DS8880 storage subsystem to deliver extreme low latency I/O access for DB2 for z/OS applications.  zHyperLink technology is intended to complement FICON technology, accelerating those I/O requests that are typically used for transaction processing.  These links are point-to-point connections between the System z CEC and the storage system and are limited to 150 meter distances.  These links do not impact the z Architecture 8 channel path limit.

From a DB2 I/O service performance perspective viewpoint, at short distances, a native FICON or zHPF originated I/O typically requires 300 Microseconds (μs) for a simple I/O operation.  The coupling facility for z Systems typically can read or write 4K of data in in under 8 Microseconds.  zHyperLink technology will provide a new short distance link from the mainframe to storage to read and write data up to 10 times faster than FICON or zHPF; reducing DB2 I/O service times to an anticipated 20-30 Microseconds.

In conclusion, with a promise of 10 times faster processing, as per its fibre optic channel technology predecessors, particularly EMIF and zHPF, zHyperLink is a revolutionary DASD I/O function and not just another DASD I/O subsystem function enhancement.  At this stage, the deployment of zHyperLink functionality is restricted to DB2 and the IBM DS8880 storage subsystem, while we eagerly await compatibility support from EMC and HDS accordingly.  Moreover, as per the evolution of zHPF, we hope for the inclusion of other I/O workloads to benefit from this paradigm changing I/O response time technology.

Finally, as always, the realm of possibility always exists for each and every System z DASD I/O subsystem to be monitored and tuned on a proactive and 24*7*365 basis.  Although all of this DASD I/O performance data has always been and still is captured by RMF (CMF) data, intelligent processing of this data requires an ever evolving Performance Management process and arguably an intelligent software solution (E.g. IntelliMagic Direction Disk Magic or Technical Storage Easy Analyze Disk Mainframe) to provide meaningful information and business decisions from ever increasing amounts of RMF (CMF) data.  In November 2016 ago I delivered the DASD I/O Performance Management Is Easy? session at the UK GSE Annual 2016 meeting accordingly…

All Flash & Substance – Is The System z Microsecond The New Millisecond?

Is 2016 the year of the All Flash disk array?  Seemingly from a System z perspective, 2016 has seen improvement in the All Flash disk array offerings from the major disk suppliers, namely EMC, HDS and IBM.  From a usability perspective, managing latency might be the overall challenge, where these ultra-fast SSD systems are delivering I/O performance response times measured in the ~250-500 Microsecond (μs) range, potentially consigning the traditional Millisecond (ms) measurement to history!

Whatever the speeds and feeds might be, as of 2016, the benchmark for a System z All Flash Disk Array is seemingly measured @ <500 Microsecond μs response time, supporting ~n PB of capacity and delivering ~nnn GB/S throughput for mixed read/write workloads.  Of course, strong encryption, typically full disk Data @ Rest Encryption (D@RE) based and full seamless data replication interoperability are also mandatory.

Historically we evolved from Data Processing to Information Technology, not only automating the capture and processing of data, but gradually evolving our processes, using this data for business advantage.  In recent years, the information explosion has dictated that each and every business must be a cognitive business, using intelligent analytics to gain insight and faster decision-making from the business data collected.

Currently the Internet of Things (IoT) supplements the medium-term Cloud, Analytics, Mobile, Social & Security (CAMSS) initiative, being the processes and associated solutions required by cognitive businesses to make timely and informed decisions, capturing deeper customer insight, ultimately delivering competitive advantage.  Therefore the 21st century business generates a significant requirement for storage capacity and performance to fully realize the benefits of this truly business aligned cognitive approach.

The largest global organizations from all verticals leverage from the power and true 24*7*365 availability and reliability of the System z Mainframe to power enormous relational databases, processing millions of customer transactions on an hourly basis.  These always-on, mission critical business environments demand the performance, reliability, TCO and System z platform integration delivered by the associated DASD (3390) subsystem.

Each and every System z user will have their IHV of choice for delivering disk storage, in alphabetical order, EMC (E.g. VMAX AFA/All Flash Array), HDS (HAF/Hitachi Accelerated Flash) or IBM (E.g. DS8888).  The choice of disk storage was forever thus, reviewing the market place and choosing the best option for your business.  What might require reflection is how the DASD I/O subsystem is managed and the associated interaction with said IHV supplier.  Systems Management solutions such as Easy Disk Analyze Mainframe (EADM) and IntelliMagic Vision (Disk Magic) will certainly simplify the analysis and presentation of DASD subsystem performance data.

However the emphasis of the actual System z DASD subsystem for an All Flash array might move from being an internal consideration, to a direct and timely communication with the IHV supplier.  Put very simply, in an environment where Mission Critical systems rely upon ultra fast processing of massive amounts of data, any flash memory issues, whether capacity or defect related will need IHV interaction ASAP, arguably “Before The Event”.  As with the System z Server itself, where we’re used to On/Off Capacity on Demand (OOCoD) processes, maybe we need to consider a similar approach with our All Flash System z DASD arrays.  For the avoidance of doubt, as opposed to waiting for an issue to impact our business, maybe we need to work smarter with our IHV, to safeguard that sufficient flash memory is available, to proactively resolve capacity or defect issues…

Aligning this with our traditional 3390 DASD I/O subsystem analysis, which might have been on a daily basis, from the rich RMF/CMF data resource, we must fully automate this process to minimize or eliminate the Mean Time To Resolution (MTTR)!  The ultimate benefit will be the delivery of meaningful messages that incorporate our 3rd party IHV supplier, who potentially with Remote Support Facility (RSF) type processes, deploys the “Golden Screwdriver” to seamlessly safeguard the performance profiles of our Mission Critical business applications, leveraging from the latest All Flash disk array.

In conclusion, as always, technology can deliver business benefits, with substance, and this includes All Flash disk arrays.  As always, what might need to evolve are the associated Systems Management processes.  Therefore asking yet another potential rhetorical question, what is more important, the System z Server or timely data access?  The diplomatic answer is that they’re equally important and if so, let’s safeguard the availability of All Flash memory for our DASD subsystems, with the requisite levels of meaningful proactive reporting and IHV supplier interaction.