Simplifying Db2 for z/OS CPU Optimization: Eradicating Inefficient SQL Processing

Without doubt the IBM Z Mainframe server is recognised as the de facto choice for storing mission critical System of record (SOR) data in database repositories for 92 of the top 100 global banks, 23 of the 25 top global airlines; the top 10 global insurers & ~70% of all Fortune 500 companies. ~80% of mission critical data is hosted by IBM Z Mainframe servers, processing 30+ Billion transactions per day, including ~90% of all credit card transactions. This data is accessed by ~1.3 Million CICS transactions per second, compared with a Google (mostly search) processing rate of ~70,000 transactions per second. Interestingly enough, despite processing so many mission critical transactions the IBM Z Mainframe server platform is only accountable for ~6.2% of global IT spend. One must draw one’s own conclusions as to why some IT professionals perceive the IBM Z Mainframe server as being a legacy platform, not worthy of consideration as a strategic IT server platform…

The digital transformation has delivered an exponential growth of data, typically classified as Cloud, Mobile & Social based. This current & ever-growing data source requires intelligent analytics to deliver meaningful business decisions, requiring agile application software delivery to gain competitive edge. This digital approach can sometimes deliver a myriad of micro business application changes, personalised for each & every customer, often delivering “pop-up” applications…

IBM Z Mainframe software costs are often criticized as being a major barrier to maintaining or indeed commissioning the platform. IBM have tried to minimize these costs with numerous sub-capacity pricing options over the last 30 years or so, but this is perceived by many as being overly complicated; although with a modicum of knowledge, a specialized personnel resource can easily control software costs. All that said, IBM have introduced Tailored Fit Pricing for IBM Z, in an attempt to simplify software cost management. A recent blog reviewed the Tailored Fit Pricing for IBM Z offering & whether you decide whether this IBM Z pricing mechanism is suitable for your organization, optimizing IBM Z CPU MSU/MIPS usage is mandatory. Recognizing that the IBM Z Mainframe server is the de facto database server for System of Record data, primarily via the Db2 subsystem, clearly optimizing Db2 CPU usage, whether OLTP transactions, typically via CICS, or the batch window, has been & always will be, worthwhile…

All too often, many IT disciplines can be classified with a generic 80/20 rule & typically data can be classified accordingly, where 80% of data is accessed 20% of the time & 20% of data is accessed 80% of the time. The challenge with such a blunt Rule of Thumb (ROT) is that it’s static, but it’s a good starting point. Ideally for any large data source, there would be a dynamic sampling mechanism that would identify the most active data, loading this into the highest speed memory resource to reduce I/O access times & therefore CPU usage. Dynamic management of such a data buffer would render the 80/20 rule extraneous to requirements, as each & every business has their own data access profile. However, a simple cost benefit & therefore Proof of Value (POV) analysis could ensue.

From a Db2 viewpoint, pre-defined structures such as buffer pools offer some relief in storing highly referenced data in a high-speed server memory resource, but this has a finite capacity versus performance benefit, not necessarily using the fastest memory structures available nor dynamically caching the most accessed data. The business considerations of not optimizing Db2 data access are:

  • Elongated Batch Processing: With ever increasing amounts of data to process & greater demands for 247365 availability & real-time access, data access optimization is fundamental for optimized service delivery, often measured by mission critical SLA & KPI metrics. Optimized batch processing is a fundamental requirement for acceptable customer facing business service delivery.
  • Slow Transaction Response Times: As the nature of customer requirements change, mobile device applications exponentially increasing the number of daily transactions, overall system resource capacity constraints are often stressed during peak hours. Optimized transaction response time is a fundamental requirement, being the most transparent service delivered to each & every end customer.

An easy but very expensive solution to remediate batch processing & transaction response issues is to provide more resources via a CPU server upgrade activity. A more sensible approach is to optimize the currently deployed resources, safeguarding that frequently accessed data is mostly if not always high speed cache resident, reducing the I/O processing overhead, reducing CPU usage, which in turn will optimize batch processing & transaction response times, while controlling associated IBM Z Mainframe server hardware & software costs.

The ubiquitous Db2 data access method is Structured Query Language (SQL) based, where IBM has their own implementation, SQL for Db2 for z/OS, which could be via the commonly used COBOL (EXEC SQL) programming language or a Db2 Connect API (E.g. ADO.NET, CLI, Embedded SQL, JDBC, ODBC, OLE DB, Perl, PHP, pureQuery, Python, Ruby, SQLJ). For Db2 Connect, there are 2 types of embedded SQL processing, static & dynamic SQL. Static SQL minimizes execution time by processing in advance. Though some relief is provided by Dynamic Statement Cache, dynamic SQL is processed when the SQL statement is submitted to the IBM Z Db2 server. Dynamic SQL is more flexible, but potentially slower. The decision to use static or dynamic SQL is typically made by the application programmer. There is a danger that Dynamic Statement Cache might be considered as a panacea for SQL CPU performance optimization, but as per any other performance activity, reviewing any historical changes is a good idea. The realm of possibility exists for the Db2 Subject Matter Expert (SME) to be pleasantly surprised that more often than not, there are still significant SQL CPU optimization opportunities…

From a generic Db2 viewpoint, with static SQL, you cannot change the form of SQL statements unless you make changes to the program. However, you can increase the flexibility of static statements by using host variables. Obviously, application program changes are not always desirable.

Dynamic SQL provides flexibility, if an application program needs to process many data types & structures, dictating that the program cannot define a model for each one, dynamic SQL overcomes this challenge. Dynamic SQL processing is facilitated by Query Management Facility (QMF), SQL Processing Using File Input (SPUFI) or the UNIX Systems Services (USS) Command Line Processor (CLP). Not all SQL statements are supported when using dynamic SQL. A Db2 application program that processes dynamic SQL accepts as input, or generates, an SQL statement in the form of a character string. Programming is simplified when you can structure programs not to use SELECT statements, or to use only those that return a known number of values of known types.

For Db2 data access, SQL statement processing requires an access path. The major SQL statement performance factors to consider are the amount of time that Db2 uses to determine the access path at run time & whether the access path is efficient. Db2 determines the SQL statement access path either when you bind the plan or package that contains the SQL statement or when the SQL statement executes. The repeating cost of preparing a dynamic SQL statement can make the performance worse when compared with static SQL statements. However, if you execute the same SQL statement often, using the dynamic SQL statement cache decreases the number of times dynamic statements must be prepared.

Typically, organizations have embraced static SQL over dynamic because static is more predictable, showing little or no change, while dynamic implies ever changing & unpredictable. Db2 performance optimization functions have been incorporated into base Db2 (E.g. Buffer Pools) & software products (E.g. IBM Db2 AI for z/OS, IBM Db2 for z/OS Optimizer, IBM Db2 Analytics Accelerator, IBM Z Table Accelerator, IZTA), with varying levels of benefit & cost. Ultimately IBM Z Mainframe customers need simple cost-efficient off-the-shelf solutions of a plug & play variety & without doubt, optimizing static SQL data processing is a pragmatic option for reducing Db2 subsystem CPU usage.

In Db2 Version 10, support for 64-bit run time was introduced, providing Virtual Storage Constraint Relief (VSCR), improving the vertical scalability of Db2 subsystems. With Db2 Version 11, the key z/Architecture benefit of 64-bit virtual addressing support was finally introduced, increasing capacity of central memory & virtual address spaces from 2 GB to 16 EB (Exabytes), eliminating most storage constraints. It therefore follows that any Db2 CPU performance optimization solution should also exploit the z/Architecture 64-bit feature, to support the ever-increasing data storage requirements of today’s digital workloads.

As we have identified, Db2 can consume significant amounts of z/OS CPU accessing & retrieving the same static frequently used data elements repetitively. Upon analysis, these static frequently used data elements are typically identified originating from a small percentage of Db2 tablespaces. Typically, at first glance these simple SQL programs are considered as low risk, but are repeatedly processed, often in peak processing times, consuming excessive CPU & increasing processing cost accordingly, typically z/OS Monthly Licence Charges (MLC) related. Db2 optimization tools for access path or buffer pool management provide some benefit, but this is not always significant & may require application changes. Patently there is a clear & present requirement for a simple plug & play solution, transparent to Db2 processing, maintaining an optimized high-performance in-memory cache of frequently used Db2 data, safeguarding data integrity in environments various, including SYSPLEX, Data Sharing, et al…

QuickSelect is a plug-in solution dynamically activated in a batch or OLTP environment (I.E. CICS, IMS/TM) intercepting repetitive SQL statements from Db2 application programs, storing the most active result set, not necessarily the entire tablespace, in a high-performance in-memory cache, returning to applications the same result set as per Db2, but much faster & using less CPU accordingly. QuickSelect is completely transparent to z/OS applications, eliminating any requirement to change/recompile/relink application source or rebind packages. QuickSelect processing can be switched on or off using a single keystroke, either defaulting to standard Db2 SQL processing or to benefit from the QuickSelect high-speed cache for optimized CPU resource usage.

The 64-bit QuickSelect server, implemented as a started task, intelligently caching data in self-managed memory above the bar, supporting up to 16 EB of memory, eliminating concerns of using any other commonly used storage areas (E.g. ECSA). The intelligent caching mechanism safeguards that only highly active data is retained, optimizing the associated cache memory size required.

QuickSelect caches frequently requested Db2 SQL result sets, returning these results to the application from QuickSelect cache, when a repetition of the same SQL is encountered. For data integrity purposes, QuickSelect immediately invalidates result sets upon detection of changes to underlying tables, implicitly validating each cache resident SQL result set. Changes to Db2 data by application programs are captured by a standard Db2 VALIDPROC process, attached to the typically small subset of frequently accessed tables of interest to QuickSelect. Db2 automatically activates the VALIDPROC routine whenever the table contents are changed by INSERT, DELETE, UPDATE or TRUNCATE statements, invalidating cached data from the updated tables automatically. For standard Db2 utilities such as LOAD/REPLACE, REORG/DISCARD & RECOVER, table-level changes are identified by a QuickSelect utility-trap, invalidating cached data from the updated tables automatically. QuickSelect also supports SYSPLEX & Data Sharing environments, supporting update activity via the same XCF functions & processes used by Db2.

QuickSelect delivers the following benefits:

  • CPU Savings: Meaningful reduction (E.g. 20%) in the Db2 SQL direct processing; 10%+ peak time CPU reduction is not uncommon.
  • Faster Processing: Optimized CPU usage delivers shorter batch processing & OLTP transaction response times, for related SLA & KPI objective compliance.
  • Transparent Implementation: No application changes required, source code, load module or Db2 package.
  • Survey Mode: Unobtrusive & minimal Db2 workload overhead data sampling to identify potential CPU savings from repetitive SQL & tables of interest, before implementation.
  • Staggered Deployment: Granular criteria (E.g. Job, Program, Table, Transaction, Etc.) implementation ability.
  • Reporting & Analytics: Extensive information detailing cache usage for Db2 programs & tables.

Since 1993 Db2 has evolved dramatically, in line with the evolution of the IBM Z Mainframe server. When considering today’s requirement for a digital world, processing ever increasing amounts of mission critical data, a base requirement to optimize CPU processing for Db2 SQL data access is mandatory. In a hybrid support environment where today’s IBM Z Mainframe support resource requires an even blend of technical & business skills, plug & play, easy-to-use & results driven solutions are required to optimize CPU usage, transparent to the subsystem & related application programs. QuickSelect is such a solution, fully exploiting 64-bit z/Architecture for ultimate scalability, identifying & resolving a common CPU consuming data access problem, for a mission critical resource, namely the Db2 subsystem, maintaining mission-critical System of Record data.

z/OS CPU optimization is a mandatory requirement for every organization, to reduce associated software & hardware costs & in theory, as a mandatory pre requisite for deploying the Tailored Fit Pricing for IBM Z pricing mechanism. Tailored Fit Pricing uses the previous 12 Months SCRT submissions to establish a baseline for MSU charging over a contracted period, typically 3 years. If there are any unused MSU resources, these are carried forward to the next year, but if those MSU resources remain unused at the end of the contracted period, they are lost, meaning the organization has paid too much. If the MSU resource exceeds the agreed Tailored Fit Pricing, excess MSU resources are charged at a discounted rate. Clearly achieving an optimal MSU baseline before embarking on a Tailored Fit Pricing contract is arguably mandatory & it therefore follows that optimizing CPU forever more, safeguards optimal z/OS MLC charging during the Tailored Fit Pricing contract. QuickSelect for Db2 is a seamless CPU optimization product that will perpetually deliver benefit, assisting organizations minimize their z/OS MLC costs, whether they continue to proactively manage the R4HA, submitting monthly SCRT reports or they embark on a Tailored Fit Pricing contract…

Tailored Fit Pricing for IBM Z: A Viable R4HA Alternative?

In a previous blog entry, I discussed the pros and cons of IBM Z Solution Consumption License Charges (SCLC): A Viable R4HA Alternative.  Recently on 14 May 2019 IBM announced Tailored Fit Pricing for IBM Z, introducing two comprehensive alternatives to the Rolling 4 Hour Average (R4HA) based pricing model, for both new and existing workloads, with a General Availability (GA) date of 21 June 2019.

To digress a little, for those of us in the Northern Hemisphere, June 21 is considered as the Summer Solstice, where the date might vary, one day before or after, namely June 20-22.  You can then further complicate things with confusing Midsummer’s Day with the Summer Solstice and Astronomical versus Meteorological seasons, but whatever, it’s a significant timeframe, with many traditions throughout Europe.  Once again, Midsummer’s Day can be any date between June 19 and June 24.  Having considered my previous review of SCLC and now the Tailored Fit Pricing announcement, I was reminded of a quotation from A Midsummer Night’s Dream by William Shakespeare, “so quick bright things come to confusion”…

The primary driver for Tailored Fit Pricing for IBM Z is to help mitigate unpredictable costs whilst continuing to deliver optimal business outcomes in the world of Digital Transformation & Hybrid Cloud.  Depending on the type of workload activity in your organisation, a tailored pricing model may be far more competitive when compared to pay-as-you-go schemes that have been typical on many x86 based cloud implementations.  Combining technology with cost competitive commercial models delivered through Tailored Fit Pricing strongly challenges the mindset that IT growth must be done on a public cloud in order to make economic sense.  Put another way, this is the IBM Marketing stance to compete with the ever-growing presence of the major 3 Public Cloud providers, namely Amazon Web Services (AWS), Microsoft Azure and Google Cloud, totalling ~60% of Public Cloud customer spend.

In essence a significant portion of The Tailored Fit Pricing for IBM Z announcement is a brand renaming activity, where the Container Pricing for IBM Z name changes to Tailored Fit Pricing for IBM Z.  The IBM Application Development and Test Solution and the IBM New Application Solution that were previously introduced under the Container Pricing for IBM Z name, are now offered under the Tailored Fit Pricing for IBM Z name.  Tailored Fit Pricing for IBM Z pricing introduces two new pricing solutions for IBM Z software running on the z/OS platform.  The Enterprise Consumption and Enterprise Capacity Solutions are both tailored to your environment and offer flexible deployment options:

  • Enterprise Consumption Solution: a tailored usage-based pricing model where compute power is measured on a per MSU basis.  MSU consumption is aggregated hourly, providing a measurement system better aligned with actual system utilization, when compared with R4HA.  Software charges are based on the total annual MSU usage, assisting users with seasonal workload pattern variations.  A total MSU used charging mechanism is designed to remove MSU capping, optimizing SLA and response time metrics accordingly.
  • Enterprise Capacity Solution: a tailored full-capacity licensing model, offering the maximum level of cost predictability.  Charges are based on the overall size of the physical hardware environment.  Charges are calculated based on the estimated mix of workloads running, while providing the flexibility to vary actual usage across workloads. Charges include increased capacity for development and test environments and reduced pricing for all types of workload growth.  An overall size charging mechanism is designed to remove MSU capping, optimizing SLA and response time metrics accordingly.

The high-level benefits associated with the Enterprise Consumption and Enterprise Capacity solutions can be summarized as:

  • Licensing models that eradicate cost control capping activities, enabling clients to fully exploit the CPU capacity installed
  • Increased CPU capacity for Development and Test (DevTest) environments, enabling clients to dramatically increase DevTest activities, without cost consideration
  • Optimized and potential lower pricing for all types of workload growth, without requiring additional IBM approvals, or additional tagging and tracking

Enterprise Solution License Charges (ESLC) are a new type of Monthly License Charge (MLC) pricing methodology for Enterprise Solutions, tailored for each individual and specific client environment and related requirements.  It was forever thus, whatever the pricing mechanism, the ubiquitous z/OS, CICS, Db2, MQ, IMS, WAS software products are the major considerations for MLC pricing mechanisms.  The Key prerequisites for Tailored Fit Pricing for IBM Z are IBM z14 Models M01-M05 or z14 Model ZR1, running the z/OS 2.2 and higher Operating System.

For new Mission Critical workloads and existing or new Development and Test (DevTest) workloads, Tailored Fit Pricing for IBM Z is clearly a great fit.  The restriction of z14 hardware is a little disappointing, where Solution Consumption License Charges (SCLC) included support for the z13 and z13s server.  I’m guessing that IBM are relying upon a significant z14 field upgrade programme in the next few years, largely based upon the Pervasive Encryption (PE) functionality.  However, for those customers that have run the IBM Z platform for decades and might have invested in cost optimization activities, including but not limited to capping, the jump to these new Enterprise Solution License Charges (ESLC) might take a while…

We could review this isolated announcement to the nth degree, but I’m not sure how productive that might be.  For sure, there is always devil in the detail, but sometimes we need to consider the big picture…

As a baby boomer myself, I see my role as passing on my knowledge to the next generations, although still wanting and striving to learn each and every day.  At this time of year, where the weather is better and roads drier, I drive my classic car a lot more and I enjoy the ability to tune the engine with my ears, hands, eyes and a strobe; getting my hands dirty!  I wonder whether the future of the IBM Z platform ecosystem is somewhat analogous to that of the combustion engine.  Several decades ago, electronics and Engine Management Systems became common place for combustion engines and now the ubiquitous laptop is plugged into the engine bay, to retrieve codes to diagnose and in theory repair faults.  For the consumer, arguably a good thing from a vehicle reliability viewpoint, but from a mechanical engineer viewpoint, have these folks become deskilled?  If you truly want your modern vehicle fixed, you will probably need a baby boomer to do this, one that doesn’t rely on a laptop, but their experience.  Although a sweeping generalisation, as there are always exceptions to any rule, the same applies to the IBM Z environment, where it was forever thus, compute power (MSU/MIPS) optimization relies upon a tune, tune, tune approach.

Whether R4HA or Full Capacity based, software cost charges will only be truly optimized if the system and ultimately application code is tuned.  A possible potential downside of not paying close attention to MSU usage, especially when considering these Enterprise Solution License Charges, is a potential isolated activity to “fix” IBM Z software costs forevermore, based upon a high MSU baseline.  Just as the combustion engine management systems simplify fault or diagnostic data collection, they don’t necessarily highlight that the vehicle owner left their cargo carrier on the vehicle roof, harming fuel efficiency.  A crude analogy for sure, but experience counts for a lot.  We have all probably encountered the Old Engineer & The Hammer story before and ultimately it’s incumbent upon us all, to safeguard that we don’t enable a rapid “death of expertise”.  Once the skills are lost, they’re lost.  Whether iStrobe from Compuware, TurboTune from Critical Path Software Inc. or the myriad of other System Monitor options, engage the experienced engineer and safeguard MSU optimization.  At this point, deploy the latest IBM Z pricing mechanism, namely Tailored Fit Pricing for IBM Z, and you will have truly optimized software costs…

IBM z14: Pervasive Encryption & Container Pricing

On 17 July 2017 IBM announced the z14 server as “the next generation of the world’s most powerful transaction system, capable of running more than 12 billion encrypted transactions per day.  The new system also introduces a breakthrough encryption engine that, for the first time, makes it possible to pervasively encrypt data associated with any application, cloud service or database all the time”.

At first glance, a cursory review of the z14 announcement might just appear as another server upgrade release, but that could be a costly mistake by the reader.  There are always subtle nuisances in any technology announcement, while finding them and applying them to your own business can sometimes be a challenge.  In this particular instance, perhaps one might consider “Persuasive Encryption & Contained Pricing”…

When IBM releases a new generation of z Systems server, many of us look to the “feeds and speeds” data and ponder how that might influence our performance and capacity profiles.  IBM state the average z14 speed compared with a z13 increase by ~10% for 6-way servers and larger.  As per usual, there are software Technology Transition Offering (TTO) discounts ranging from 6% to 21% for z14 only sites.  However, in these times where workload profiles are rapidly changing and evolving, it’s sometimes easy to overlook that IBM have to consider the holistic position of the IBM Z world.  Quite simply, IBM has many divisions, Hardware, Software, Services, et al.  Therefore there has to be interaction between the hardware and software divisions and in this instance, IBM have delivered a z14 server that is security focussed, with their Pervasive Encryption functionality.

Pervasive Encryption provides a simple and transparent approach for z Systems security, enabling the highest levels of data encryption for all data usage scenarios, for example:

  • Processing: When retrieved from files and processed by applications
  • In Flight: When being transmitted over internal and external networks
  • At Rest: When stored in database structures or files
  • In Store: When stored in magnetic storage media

Pervasive Encryption simplifies and reduces costs associated when protecting data by policy (I.E. Subset) or En Masse (I.E. All Of The Data, All Of the Time), achieving compliance mandates.  When considering the EU GDPR (European Union General Data Protection Regulation) compliance mandate, companies must notify relevant parties within 72 hours of first having become aware of a personal data breach.  Additionally organizations can be fined up to 4% of annual global turnover or €20 Million (whichever is greater), for any GDPR breach unless they can demonstrate that data was encrypted and keys were protected.

To facilitate this new approach for encryption, the IBM z14 infrastructure incorporates several new capabilities integrated throughout the technology stack, including Hardware, Operating System and Middleware.  Integrated CPU chip cryptographic acceleration is enhanced, delivering ~600% increased performance when compared with its z13 predecessor and ~20 times faster than competitive server platforms.  File and data set encryption is optimized within the Operating Systems (I.E. z/OS), safeguarding transparent and optimized encryption, not impacting application functionality or performance.  Middleware software subsystems including DB2 and IMS leverage from these Pervasive Encryption techniques, safeguarding that High Availability databases can be transitioned to full encryption without stopping the database, application or subsystem.

Arguably IBM had to deliver this type of security functionality for its top tier z Systems customers, as inevitably they would be impacted by compliance mandates such as GDPR.  Conversely, the opportunity to address the majority of external hacking scenarios with one common approach is an attractive proposition.  However, as always, the devil is always in the detail, and given an impending deadline date of May 2018 for GDPR compliance, I wonder how many z Systems customers could implement the requisite z14 hardware and related Operating System (I.E. z/OS) and Subsystem (I.E. CICS, DB2, IMS, MQ, et al) .upgrades before this date?  From a bigger picture viewpoint, Pervasive Encryption does offer the requisite functionality to apply a generic end-to-end process for securing all data, especially Mission Critical data…

Previously we have considered the complexity of IBM z Systems pricing mechanisms and in theory, the z14 announcement tried to simplify some of these challenges by building upon and formalizing Container Pricing.  Container Pricing is intended to greatly simplify software pricing for qualified collocated workloads, whether collocated with other existing workloads on the same LPAR, deployed in a separate LPAR or across multiple LPARs.  Container pricing allows the specified workload to be separately priced based on a variety of metrics.  New approved z/OS workloads can be deployed collocated with other sub-capacity products (I.E. CICS, DB2, IMS, MQ, z/OS) without impacting cost profiles of existing workloads.

As per most new IBM z Systems pricing mechanisms of late, there is a commercial collaboration and exchange required between IBM and their customer.  Once a Container Pricing solution is agreed between IBM and their customer, for an agreed price, an IBM Sales order is initiated, triggering the creation of an Approved Solution ID.  The IBM provided solution ID is a 64-character string representing an approved workload with an entitled MSU capacity, representing a Full Capacity Pricing Container used for billing purposes.

Previously we considered the importance of WLM for managing z/OS workloads and its interaction with soft-capping, and this is reinforced with this latest IBM Container Pricing mechanism.  The z/OS Workload Manager (WLM) enables Container Pricing using a resource classified as the Tenant Resource Group (TRG), defining the workload in terms of address spaces and independent enclaves.  The TRG, combined with a unique Approved Solution ID, represents the IBM approved solution.  As per standard SCRT processing, workload instrumentation data is collected, safeguarding that this workload profile does not directly impact the traditional peak LPAR Rolling Four-Hour Average (R4HA).  The TRG also allows the workload to be metered and optionally capped, independent of other workloads that are running collocated in the LPAR.

MSU utilization of the defined workload is recorded by WLM and RMF, subsequently processed by SCRT to subtract the solution MSU capacity from the LPAR R4HA.  The solution can then be priced independently, based on MSU resource consumed by the workload, or based upon other non-MSU values, specifically a Business Value Metric (E.g. Number of Payments).  Therefore Container Pricing is much simpler and much more flexible than previous IBM collocated workload mechanism, namely IWP and zCAP.

Container Pricing eliminates the requirement to commission specific new environments to optimize MLC pricing.  By deploying a standard IBM process framework, new workloads can be commissioned without impacting the R4HA of collocated workloads, being deployed as per business requirements, whether on the same LPAR, a separate LPAR, or dispersed across multiple LPAR structures.  Quite simply, the standard IBM process framework is the Approved Solution ID, associating the client based z/OS system environment to the associated IBM sales contract.

In this first iteration release associated with the z14 announcement, Container Pricing can be deployed in the following three solution based scenarios:

  • Application Development and Test Solution: Add up to 3 times more capacity to existing Development and Test environments without any additional monthly licensing costs; or create new LPAR environments with competitive pricing.
  • New Application Solution: Add new z/OS microservices or applications, priced individually without impacting the cost of other workloads on the same system.
  • Payments Pricing Solution: A single agreed value based price for software plus hardware or just software, via a number of payments processed metric, based on IBM Financial Transaction Manager (FTM) software.

IBM state z14 support for a maximum 2 million Docker containers in an associated maximum 32 TB memory configuration.  In conjunction with other I/O enhancements, IBM state a z14 performance increase of ~300%, when compared with its z13 predecessor.  Historically the IBM Z platform was never envisaged as being the ideal container platform.  However, its ability to seamlessly support z/OS and Linux, while the majority of mission critical Systems Of Record (SOR) data resides on IBM Z platforms, might just be a compelling case for microservices to be processed on the IBM Z platform, minimizing any data latency transfer.

Container Pricing for z/OS is somewhat analogous to the IBM Cloud Managed Services on z Systems pricing model (I.E. CPU consumption based).  Therefore, if monthly R4HA peak processing is driven by an OLTP application, or any other workload for that matter, any additional unused capacity in that specific SCRT reporting month can be allocated for no cost to other workloads.  Therefore z/OS customers will be able to take advantage of this approach, processing collocated microservices or applications for a zero or nominal cost.

County Multiplex Pricing (CMP) Observation: The z14 is the first new generation of IBM Z hardware since the introduction of the CMP pricing mechanism.  When a client first implements a Multiplex, IBM Z server eligibility cannot be older than two generations (I.E. N-2) prior to the most recently available server (I.E. N).  Therefore the General Availability (GA) of z14, classifies the z114 and z196 servers as previously eligible CMP machines.  IBM will provide a 3 Month grace period for CMP transition activities for these N-3 servers, namely z114 and z196.  Quite simply, the first client CMP invoice must be submitted within 90 days of the z14 GA date, namely 13 September 2017, no later than 1 January 2018.

In conclusion, Pervasive Encryption is an omnipresent z14 function integrated into every data lifecycle stage, which could easily be classified as Persuasive Encryption, simplifying the sometimes arduous process of classifying and managing mission-critical data.  As cybersecurity becomes an omnipresent clear and present danger, associated with impending and increasingly punitive compliance mandates such as GDPR, the realm of possibility exists to resolve this high profile corporate challenge once and for all.

Likewise, Container Pricing provides a much needed simple-to-use framework to drive MSU cost optimization for new workloads and could easily be classified as Contained Pricing.  The committed IBM Mainframe customer will upgrade their z13 server environment to z14, as part of their periodic technology refresh approach.  Arguably, those Mainframe customers who have been somewhat hesitant in upgrading from older technology Mainframe servers, might just have a compelling reason to upgrade their environments to z14, safeguarding cybersecurity challenges and evolving processes to contain z/OS MLC costs.

Optimize Your System z ROI with z Operational Insights (zOI)

Hopefully all System z users are aware of the Monthly Licence Charge (MLC) pricing mechanisms, where a recurring charge applies each month.  This charge includes product usage rights and IBM product support.  If only it was that simple!  We then encounter the “Alphabet Soup” of acronyms, related to the various and arguably too numerous MLC pricing mechanism options.  Some might say that 13 is an unlucky number and in this case, a System z pricing specialist would need to know and understand each of the 13 pricing mechanisms in depth, safeguarding the lowest software pricing for their organization!  Perhaps we could apply the unlucky word to such a resource.  In alphabetical order, the 13 MLC pricing options are AWLC, AEWLC, CMLC, EWLC, MWLC, MzNALC, PSLC, SALC, S/390 Usage Pricing, ULC, WLC, zELC and zNALC!  These mechanisms are commercial considerations, but what about the technical perspective?

Of course, System z Mainframe CPU resource usage is measured in MSU metrics, where the usage of Sub-Capacity allows System z Mainframe users to submit SCRT reports, incorporating Monthly License Charges (MLC) and IPLA software maintenance, namely Subscription and Support (S&S).  We then must consider the Rolling 4-Hour Average (R4HA) and how best to optimize MSU accordingly.  At this juncture, we then need to consider how we measure the R4HA itself, in terms of performance tuning, so we can minimize the R4HA MSU usage, to optimize cost, without impacting Production if not overall system performance.

Finally, we then have to consider that WLC has a ~17-year longevity, having been announced in October 2000 and in that time IBM have also introduced hardware features to assist in MSU optimization.  These hardware features include zIIP, zAAP, IFL, while there are other influencing factors, such as HyperDispatch, WLM, Relative Nest Intensity (RNI), naming but a few!  The Alphabet Soup continues…

In summary, since the introduction of WLC in Q4 2000, the challenge for the System z user is significant.  They must collect the requisite instrumentation data, perform predictive modelling and fully comprehend the impact of the current 13 MLC pricing mechanisms and their interaction with the ever-evolving System z CPU chip!  In the absence of such a simple to use reporting capability from IBM, there are a plethora of 3rd party ISV solutions, which generally are overly complex and require numerous products, more often than not, from several ISV’s.  These software solutions process the instrumentation data, generating the requisite metrics that allows an informed decision making process.

Bottom Line: This is way too complex and are there any Green Shoots of an alternative option?  Are there any easy-to-use data analytics based options for reducing MSU usage and optimizing CPU resources, which can then be incorporated into any WLC/MLC pricing considerations?

In February 2016 IBM launched their z Operational Insights (zOI) offering, as a new open beta cloud-based service that analyses your System z monitoring data.  The zOI objective is to simplify the identification of System z inefficiencies, while identifying savings options with associated implementation recommendations. At this juncture, zOI still has a free edition available, but as of September 2016, it also has a full paid version with additional functionality.

Currently zOI is limited to the CICS subsystem, incorporating the following functions:

  • CICS Abend Analysis Report: Highlights the top 10 types of abend and the top 10 most abend transactions for your CICS workload from a frequency viewpoint. The resulting output classifies which CICS transactions might abend and as a consequence, waste processor time.  Of course, the System z Mainframe user will have to fix the underlying reason for the CICS abend!
  • CICS Java Offload Report: Highlights any transaction processing workload eligible for IBM z Systems Integrated Information Processor (zIIP) offload. The resulting output delivers three categories for consideration.  #1; % of existing workload that is eligible for offload, but ran on a General Purpose CP.  #2; % of workload being offloaded to zIIP.  #3; % of workload that cannot be transferred to a zIIP.
  • CICS Threadsafe Report: Highlights threadsafe eligible CICS transactions, calculating the switch count from the CICS Quasi Reentrant Task Control Block (QR TCB) per transaction and associated CPU cost. The resulting output identifies potential CPU savings by making programs threadsafe, with the associated CICS subsystem changes.
  • CICS Region CPU Constraint: Highlights CPU constrained regions. CPU constrained CICS regions have reduced performance, lower throughput and slower transaction response, impacting business performance (I.E. SLA, KPI).  From a high-level viewpoint, the resulting output classifies CICS Region performance to identify whether they’re LPAR or QR constrained, while suggesting possible remedial actions.

Clearly the potential of zOI is encouraging, being an easy-to-use solution that analyses instrumentation data, classifies the best options from a quick win basis, while providing recommendations for implementation.  Having been a recent user of this new technology myself, I would encourage each and every System z Mainframe user to try this no risk IBM z Operational Insights (zOI) software offering.

The evolution for all System z performance analysis software solutions is to build on the comprehensive analysis solutions that have evolved in the last ~20+ years, while incorporating intelligent analytics, to classify data in terms of “Biggest Impact”, identifying “Potential Savings”, evolving MIPS measurement, to BIPS (Biggest Impact Potential Savings) improvements!

IBM have also introduced a framework of IT Operations Analytics Solutions for z Systems.  This suite of interconnected products includes zOI, IBM Operations Analytics for z Systems, IBM Common Data Provider for z/OS and IBM Advanced Workload Analysis Reporter (IBM zAware).  Of course, if we lived in a perfect world, without a ~20 year MLC and WLC longevity, this might be the foundation for all of our System z CPU resource usage analysis.  Clearly this is not the case for the majority of System z Mainframe customers, but zOI does offer something different, with zero impact, both from a system impact and existing software interoperability viewpoint.

Bottom Line: Optimize Your System z ROI via zOI, Evolving From MIPS Measurement to BIPS Improvements!

Are You Ready For z Systems Workload Pricing for Cloud (zWPC) for z/OS?

Recently IBM announced the z Systems Workload Pricing for Cloud (zWPC) for z/OS pricing mechanism, which can minimize the impact of new Public Cloud workload transactions on Sub-Capacity license charges.  Such benefits will be delivered where higher Public Cloud workload transaction volumes may cause a spike in machine utilization.  Of course, if this looks familiar and you have that feeling of déjà vu, this is a very similar mechanism to Mobile Workload Pricing (MWP)…

Put simply, zWPC applies to any organization that has implemented Sub-Capacity pricing via the basic AWLC or AEWLC pricing mechanisms, for the usual MLC software suspects, namely z/OS, CICS, DB2, IMS, MQ and WebSphere Application Server (WAS).  An eligible transaction is one classified as Public Cloud originated, connecting to a z/OS hosted transactional service and/or data source via a REST or SOAP web service.  Public Cloud workloads are defined as transactions processed by named Public Cloud applications transactions identified as originating from a recognized Public Cloud offering, including but not limited to, Amazon Web Services (AWS), Microsoft Azure, IBM Bluemix, et al.

As per MWP, SCRT calculates the R4HA for Public Cloud transaction GP MSU resource usage, subtracting 60% of those values from the traditional Sub-Capacity software eligible MSU metric, with LPAR granularity, for each and every reporting hour.  The software program values for the same hour are aggregated for all Sub-Capacity eligible LPARs, deriving an adjusted Sub-Capacity value for each reporting hour.  Therefore SCRT determines the billable MSU peak for a given MLC software program on a CPC using the adjusted MSU values.  As per MWP, this will only be of benefit, if the Public Cloud originated transactions generate a spike in the current R4HA.

One of the major challenges for implementing MWP was identifying those transactions eligible for consideration.  Very quickly IBM identified this challenge and offered a WorkLoad Manager (WLM) based solution, to simplify reporting for all concerned.  This WLM SPE (OA47042), introduced a new transaction level attribute in WLM classification, allowing for identification of mobile transactions and associated processor consumption.  These Reporting Attributes were classified as NONE, MOBILE, CATEGORYA and CATEGORYB.  Obviously IBM made allowances for future workload classifications, hence it would seem Public Cloud will supplement Mobile transactions.

In a previous z/OS Workload Manager (WLM): Balancing Cost & Performance blog post, we considered the merits of WLM for optimizing z/OS software costs, while maintaining optimal performance.  One must draw one’s own conclusions, but there seemed to be a strong case for WLM reporting to be included in the z/OS MLC Cost Manager toolkit.  The introduction of zWPC, being analogous to MWP, where reporting can be simplified with supplied and supported WLM function, indicates that intelligent and proactive WLM reporting makes sense.  Certainly for 3rd party Soft-Capping solutions, the ability to identify MWP and zWPC eligible transactions in real-time, proactively implementing MSU optimization activities seems mandatory.

The Workload X-Ray (WLXR) solution from zIT Consulting delivers this WLM reporting function, seamlessly integrating with their zDynaCap and zPrice Manager MSU optimization solutions.  Of course, there is always the possibility to create your own bespoke reports to extract the relevant information from SMF records and subsystem diagnostic data, for input to the SCRT process.  However, such a home-grown process will only work on a monthly reporting basis and not integrate with any Soft-Capping MSU management, which will ultimately control z/OS MLC costs.

In conclusion, from a big picture viewpoint, in the last 2 years or so, IBM have introduced several new Sub-Capacity pricing mechanisms to help System z Mainframe users optimize z/OS MLC costs, namely Mobile Workload Pricing (MWP), Country Multiplex Pricing (CMP) and now z Systems Workload Pricing for Cloud (zWPC).  In theory, at least one of these new pricing mechanisms should deliver benefit to the committed System z user, deploying this server for strategic and Mission Critical workloads.  With the undoubted strategic importance associated with Analytics, Blockchain, Cloud, DevOps, Mobile, Social, et al, the landscape for System z workloads is rapidly evolving and potentially impacting those sacrosanct legacy Mission Critical workloads.  Seemingly the realm of possibility exists that Cloud and Mobile originated transactions will dominate access to System z Mainframe System Of Record (SOR) data repositories, which generates a requirement to optimize associated MLC costs accordingly.  Of course, for some System z users, such Cloud and Mobile access might not be on today’s to-do list, but inevitably it’s on the horizon, and so why not implement the instrumentation ability ASAP!

z/OS Workload Manager (WLM): Balancing Cost & Performance

A sophisticated mechanism is required to orchestrate the allocation of System z resources (E.g. CPU, Memory, I/O) to multiple z/OS workloads, requiring differing business processing priorities. Put very simply, a mechanism is required to translate business processing requirements (I.E. SLA) into an automated and equitable z/OS performance manager. Such a mechanism will safeguard the highest possible throughput, while delivering the best possible system responsiveness. Ideally, such a mechanism will assist in delivering this optimal performance, for the lowest cost; for z/OS, primarily Workload License Charges (WLC) related. Of course, the Workload Management (WLM) z/OS Operating System component delivers this functionality.

A rhetorical question for all z/OS Performance Managers and z/OS MLC Cost Managers would be “how much importance does your organization place on WLM and how proactively do you manage this seemingly pivotal z/OS component”? In essence, this seems like a ridiculous question, yet there is evidence that suggests many organizations, both customer and ISV alike, don’t necessarily consider WLM to be a fundamental or high priority performance management discipline. Let’s consider several reasons why WLM is a fundamental component in balancing cost and performance for each and every z/OS environment:

  • CPU (MSU) Resource Capping: Whatever the capping method (I.E. Absolute, Hard, Soft), WLM is a controlling mechanism, typically in conjunction with PR/SM, determining when capping is initiated, how it is managed and when it is terminated. Therefore from a dispassionate viewpoint, any 3rd party ISV product that performs MSU optimization via soft capping mechanisms should ideally consider the same CPU (E.g. SMF Type 70, 72, 99) instrumentation data as WLM. Some solutions don’t offer this granularity (E.g. AutoSoftCapping, iCap).
  • MLC R4HA Cost Management: WLM is the fundamental mechanism for controlling this #1 System z software TCO component; namely WLM collects 48 consecutive metric CPU MSU resource usage every 5 Minutes, commonly known as the Rolling 4 Hour Average (R4HA). In an ideal world, an optimally managed workload that generates a “valid monthly peak”, will fully utilize this “already paid for” available CPU MSU resource for the remainder of the MLC eligible month (I.E. Start of the 2nd day in a calendar month, to the end of the 1st day in the next calendar month). More recently, Country Multiplex Pricing (CMP) allows an organization to move workloads between System z server (I.E. CPC) structures, without cost consideration for cumulative R4HA peaks. Similarly, Mobile Workload Pricing (MWP) reporting will be simplified with WLM service definitions in z/OS 2.2. Therefore it seems prudent that real-time WLM management, both in terms of real-time reporting and pro-active decision making makes sense.
  • System z Server CPU Management: As System z server CPU chips evolve (E.g. CPU Chip Cache Hierarchy and Relative Nest Intensity), there are complementary changes to the z/OS Operating System management components. For example, HiperDispatch Mode delivers CPU resource usage benefit, considering CPU chip cache resources, intelligently allocating workload to as few logical processors as possible. It therefore follows that prioritization of workloads via WLM policy definitions becomes increasingly important. In this instance one might consider that CPU MF (SMF Type 113) and WLM Topology (SMF Type 99) are complementary reporting techniques for System z server design and management.

Since its announcement in September 1994 (I.E. MVS/ESA Version 5), WLM has evolved to become a fully-rounded and highly capable z/OS System Resources Manager (SRM), simply translating business prioritization policies into dynamic function, optimizing System z CPU, Memory and I/O resources. More recently, WLM continues to simplify the management of CPU chip cache hierarchy resources, while reporting abilities gain in strength, with topology reporting and the promise of simplified MWP reporting. Moreover, WLM resource management becomes more granular and seemingly the realm of possibility exists to “micro manage” System z performance, as and if required. Conversely, WLM provides the opportunity to simplify System z performance management, with intelligent workload differentiation (I.E. Subsystem Enclave, Batch, JES, USS, et al).

Quite simply, IBM are providing the instrumentation and tools for the 21st Century System z Performance and Software Cost Subject Matter Expert (SME) to deliver optimal performance for minimal cost. However, it is incumbent for each and every System z user to optimize software TCO, proactively implementing new processes and leveraging from System z functions accordingly.

Returning to that earlier rhetorical question about the importance of WLM; seemingly its importance is without doubt, primarily because of its instrumentation and management abilities of increasingly cache rich System z CPU chips and its fundamental role in controlling CPU MSU resource, vis-à-vis the R4HA.

Although IBM will provide the System z user with function to optimize system performance and cost, for obvious commercial reasons IBM will not reduce the base cost of System z MLC software. However, recent MLC pricing announcements, namely Country Multiplex Pricing (CMP), Mobile Workload Pricing (MWP) and Collocated Application Pricing (zCAP) provide tangible options to reduce System z MLC TCO. Therefore the System z user might need to consider how they can access real-time WLM performance metrics, intelligently combining this instrumentation data with function to intelligently optimize CPU MSU resource, managing the R4HA accordingly.

Workload X-Ray (WLXR) from zIT Consulting simplifies WLM performance reporting, enabling users to drill down into the root cause of performance variances in a very fast and easy way. WLXR assists in root cause problem determination by zooming in, starting from a high level overview, going right down to detailed Service Class performance information, such as the Performance Index (PI), showing potential bottleneck situations during peak time. Any system overhead considerations are limited, as WLXR delivers meaningful real time information on a “need to know” basis.

A fundamental design objective for WLXR is data reduction, only delivering the important information required for timely and professional workload management. Straight to the point information instead of data overload, sometimes from a plethora of data sources (E.g. SMF, System Monitors, et al). WLXR incorporates the following easy-to-use functions:

  • Simplified Data Collection & Storage: Minimal system overhead TCP/IP based agents periodically (E.g. 5, 15, 60 Minutes) collect CPU (Type 70) and WLM (Type 72) data. Performance data is stored centrally in near real-time, building a historical repository with intelligent analytics for meaningful information presentation.
  • Intelligent GUI Based Information Presentation: Meaningful decision based reports and graphs detailing CPU (E.g. MSU, R4HA, Weight) and WLM (E.g. Service Class, Performance Index, Response Time, Transaction Workflow) resource usage. A drill-down design provides a granularity of data presentation, for Management Summary to 3rd Level Technical Diagnostics use.
  • Corporate Identity Branding: A modular template design, allowing for easy corporate identity branding, with flexibility to easily add additional reports, as and if required.

Without doubt, WLM is a significant z/OS System Resources Management function, simplifying the translation of business workload requirements (I.E. Service Level Agreement) into timely and proactive allocation of major System z hardware resources (I.E. CPU, Memory, I/O). This management of System z resources has been forever thus for 20+ years, while WLM has always offered “software cost control” functionality, working with the various and evolving CPU capping techniques. What might not be so obvious, is that there is a WLM orientated price versus performance correlation, which has become more evident in the last 5 years or so. Whether Absolute Capping, HiperDispatch, Mobile Workload Pricing, Country Multiplex Pricing or evolving Soft Capping techniques, the need for System z users to integrate z/OS MLC pricing considerations alongside WLM performance based management is evident.

Historically there was not a clear and identified need for a z/OS Performance/Capacity Manager to consider MLC costs in their System z server designs. However, there is a clear and present danger that this historic modus operandi continues and there will only be one financial winner, namely IBM, with unnecessarily high MLC charges. Each and every System z user, whether large or small, can safeguard the longevity of their IBM Mainframe platform by recognizing and deploying proactive and current System z MLC cost management processes.

All too often it seems that capping can be envisaged as punitive, degrading system performance to reduce System z MLC costs. Such a notion needs to be consigned to history, with a focussed perspective on MSU optimization, where the valuable and granular MSU resource is allocated to the workload that requires such CPU resource, with near real-time performance profiling. If we perceive MSU optimization to be R4HA based and that IBM are increasing WLM function to assist this objective, CPU capping can be a benefit that does not adversely impact performance. As previously stated, once a valid R4HA peak has occurred, that high MSU watermark is available for the remainder of the MLC billing period. Similarly at a more granular level, once a workload has peaked and its MSU usage declines, the available MSU can be redirected to other workloads. With the introduction of Country Multiplex Pricing, System z users no longer need to concern themselves about creating a higher R4HA peak, when moving workloads between System z servers.

Quite simply, from the two most important perspectives, performance and cost optimization, WLM provides the majority of functionality to assist System z users get the best performance for the lowest cost. Analytics based products like Workload X-Ray (WLXR) assist this endeavour, analysing WLM data in near real-time from a performance and MLC cost perspective. It therefore follows that if this important information is also available for sophisticated MSU optimization solutions, which consider WLM performance (E.g. zDynaCap, zPrice Manager), then proactive performance and cost management follows. It’s hard to envisage how a fully-rounded MSU optimization decision can be implemented in near real-time, from an MSU optimization solution that does not consider WLM performance metrics…

How to Connect Mobile Workloads to System z

Despite potential security concerns, primarily data encryption and multiple-factor authentication related, mobile transactions continue to increase their share of the market, accounting for up to half of online transactions. Mobile payments now account for 30%+ of all global online transactions as of Q3 2015, continuing the upward trend experienced for the last several years. Although there are global differences in mobile transaction adoption, all global locations are experiencing rapid growth in mobile transaction adoption. Furthermore, as a general rule of thumb, seemingly ~66% of mobile transactions originate from a smartphone, a ~2:1 ratio when compared with tablet devices. Therefore it seems highly probable that smartphone originated mobile transactions will become the de facto standard for online transactions…

For System z users, the majority of their TCO continues to be IBM MLC software related and seemingly the realm of possibility exists for retail operations to reduce IBM MLC TCO as a result of modernizing their business for this mobile transaction phenomenon. Recognizing the security, scalability and transaction ability of the System z platform, why wouldn’t it be the ideal platform for mobile transactions? Furthermore, deploying mobile workloads that can take advantage of modern low cost System z pricing metrics, namely System z Collocated Application Pricing (zCAP) and Mobile Workload Pricing (MWP) for z/OS, could substantially reduce IBM MLC TCO. In theory, existing legacy applications might become somewhat static in nature, as mobile transactions replace existing traditional transaction mechanisms. Therefore the cost per business transaction reduces, potentially significantly.

So, just how easy is it to connect mobile transactions to the System z platform?

z/OS Connect is a software function engineered to leverage from the Liberty Profile for z/OS, acting as an enabler of connectivity between the mobile environment (client) and the System z platform (host). Put another way, z/OS Connect exposes System z assets for mobile and cloud workloads. Quite simply z/OS Connect delivers JSON (JavaScript Object Notation) and REST (REpresentational State Transfer) functionality to leverage from existing z/OS subsystems (E.g. CICS, IMS, Batch, et al). These traditional System z transaction systems (E.g. CICS, IMS) often integrated with DB2, are repositories for vast amounts of business transactions and data. There is no incremental cost for z/OS Connect usage, being packaged with WebSphere Application Server (WAS), CICS and IMS software products.

z/OS Connect provides a discovery function allowing developers to query services that have been configured for a z/OS Connect instance. A single z/OS Connect REST call returns a list of all configured services and another REST call will return the details of a given service. Importantly, developers only need to know the REST API service and associated JSON requirements to achieve this mobile device to System z interoperability; they do not need to know the underlying CICS or IMS subsystem. z/OS Connect incorporates a data conversion function that maps JSON to the host (I.E. CICS or IMS) data format requirement. Put really simply, when a request is received, z/OS Connect converts the data for CICS or IMS subsystem processing and when a response is produced, z/OS Connect converts the data back to JSON.

From a security viewpoint, standard or bespoke code can be used for control before and after a request is processed, identified as an interceptor. For Security, the calling user identity can be checked against defined roles, determining if they have authority to use z/OS Connect or the configured service. On z/OS the security interface is SAF, supplemented by an External Security Manager (ESM), namely ACF2, RACF or TopSecret. For Audit, request information can be logged via SMF for later analysis. Information about each request is logged, including timestamp, bytes processed, response time and USERID.

To summarize, z/OS Connect is designed to simplify the integration of mobile systems and z/OS assets. Delivering a consistent front-end interface for mobile systems via REST and JSON, z/OS Connect seamlessly integrates with WAS, CICS and IMS subsystems for data processing. In theory, a developer could code a mobile workload application, with no knowledge of the System z platform.

In conclusion, it seems we have to accept the adoption of the smartphone device for processing an ever increasing amount of online transactions. The realm of possibility exists that online transactions (click) will continue to displace traditional and legacy (brick) transactions. Therefore as businesses evolve to accommodate mobile transactions, they should strive to reduce their IBM MLC TCO accordingly, delivering JSON and REST applications that can leverage from optimal cost z/OS MLC software, primarily via the zCAP and MWP pricing mechanisms. z/OS Connect is one such option that simplifies the timely delivery of mobile workload applications.

System z MLC Pricing Increases: Look After The Pennies…

Recently IBM announced ~4% price increases in z/OS Monthly License Charges (MLC) for selected Operating System and Middleware software programs and associated features. Specifically, price increases will apply to the VWLC, AWLC, EWLC, AEWLC, PSLC, FWLC and TWLC pricing metrics. Notably, SDSF price increases will be ~20% with Advanced Function Printing (AFP) product price increases of ~13-24%. In a global economy where inflation rates for The USA and Western Europe are close to 0%, one must draw one’s own conclusions accordingly. Lets’ not forget that product version changes typically have an associated price increase. From a contractual viewpoint, IBM only have to provide 90 days advance notice for such price changes, in this instance, IBM provided 150+ days advanced notice.

Price increases are inevitable and as always, it’s better to be proactive as opposed to reactive to such changes. As always, the old proverbs always make good sense and in this instance, “look after the Pennies and the Pounds will look after themselves”! This periodic IBM price increase is inevitable, but is not the underlying issue for controlling System z software costs. For many years, since 1994 to be precise, when IBM introduced Parallel Sysplex License Charges (PSLC), the need for IBM Mainframe users to minimize MSU usage has been of high if not critical importance. Nothing has changed in this 20+ year period and even though IBM might have introduced Sub-Capacity and specialty engines to minimize chargeable MSU usage, has each and every System z user optimized their MSU usage? Ideally this would not be a rhetorical question, rather being a “Golden Rule”, where despite organic CPU capacity increases of ~10% per annum, a System z environment could maintain near static IBM MLC software costs.

I have written several blog entries and presented on this subject matter over the years, for example:

The simple bottom line is that System z MLC software accounts for ~20-35% of the overall System z TCO, typically being the #1 expenditure item. For that reason alone, it’s incumbent for each and every System z user to safeguard they have the technical and commercial skills in place to manage this cost item, not as an afterthought, but inbuilt into each and every System z process, from application design, through to that often neglected afterthought, application tuning.

Many System z organizations might try to differentiate between a nuance of System and Application tuning, but such a “not my problem” type attitude is not acceptable and will be imposing a significant financial burden on each and every organization.

A dispassionate and pragmatic approach is required for optimizing System z CPU usage. In this timeframe, let’s examine the ~20% SDSF price increase. IBM will quite rightly state that in conjunction with their z/OS 2.2 release, there are significant SDSF product function advancements, including zIIP offload, REXX interoperability and increased information delivery. However are such function improvements over and above the norm and not expected as a Business As Usual (BAU) product improvements, which should be included in the Service & Support (S&S) or Monthly License Charges (MLC) paid for software?

In October 2013 I wrote a blog entry; Mainframe ISV Software: Is Continuous Product Improvement Always Evident? The underlying message was that an ISV should deliver the best product they can, for each and every release, without necessarily increasing software costs. In this particular instance, the product was an SDSF equivalent, namely (E)JES, which many years ago delivered all of the function incorporated in SDSF for z/OS 2.2, but for a fraction of the cost…

As of 1 November 2015, IBM will start billing cycles for Country Multiplex Pricing (CMP), which requires the October 2015 version of SCRT, namely V23R10. A Multiplex is defined as a collection of all System z servers in one country, measured as one System z server for software sub-capacity reporting. Sub-Capacity program utilization peaks across the Multiplex will be measured, as opposed to separate peaks by System z servers. CMP also provides the flexibility to move and run workloads anywhere with the elimination of Sysplex aggregation pricing rules.

Migrating to CMP is focussed on CPU capacity growth and flexibility going forward. Therefore System z users should not expect price reductions for their existing workloads upon CMP deployment. Indeed there are CMP deployment considerations. A CMP MSU baseline (base) needs to be established, where this MSU Base and associated MLC Base Factor is established for each sub-capacity MLC product and each applicable feature code. These MSU and MLC bases represent the previous 3 Month averages reported by SCRT before commencing CMP. Quite simply, to gain the most from CMP, the System z user must safeguard that their R4HA for each and every MLC product is optimized, before setting the CMP baseline, otherwise CMP related cost savings going forward are likely to be null.

From a very high-level management viewpoint, we must observe that IBM are a commercial organization, and although IBM provide mechanisms for controlling cost going forward, only the System z user can optimize System z MLC cost for their organization. Arguably with CMP, Soft-Capping isn’t a consideration, it’s mandatory.

Put very simply, each and every System z user can safeguard that they look after the Pennies (Cents) and the Pounds (Euros, Dollars) will look after themselves by paying careful attention to System z MLC software costs. Setting a baseline of System z MLC costs is mandatory, whether for the first time, or to set a new baseline for CMP deployment. Maintaining or lowering this System z MLC cost baseline should or arguably must be the objective going forward, even when considering 10% organic CPU growth, each and every year. System z decision-makers and managers must commit to such an objective and safeguard the provision of adequately skilled personnel to optimize such a considerable TCO cost line item (I.E. MLC @ ~20-35% of System z TCO). In an ecosystem with technical resources including DBA, Systems Programmer, Capacity Planner, Application Personnel, Performance Tuning, et al, why wouldn’t there be a specialist Software Cost Manager?

Let’s consider how even an inexperienced System z user can maintain a baseline of System z MLC costs, even with organic CPU capacity growth of 10% per annum:

  • System z Server Upgrade: Higher specification CPU chips or Technology Transition Offering (TTO) pricing metrics deliver 10%+ cost per MSU benefits.
  • System z Specialty Engines: Over time, more and more application workload can be offloaded to zIIP processors, with no sub-capacity MLC software charges.
  • System z Software Version Upgrades: Major subsystems such as CICS, DB2, IMS, MQSeries and WebSphere deliver opportunity to lower cost per MSU; safeguard such function exploitation.
  • Application Tuning: Whether SQL, COBOL, Java, et al, or the overall I/O subsystem, safeguard that latest programming techniques and I/O subsystem functions are exploited.
  • New Application Deployment: As and when possible, deploy new or convert existing workloads to benefit from the optimal MLC pricing metric; previously zNALC, nowadays zCAP.
  • Technical & Commercial Skills Currency: Safeguard personnel have the latest System z software pricing knowledge, ideally from an independent 3rd party such as Watson & Walker.

In conclusion, as householders we have the opportunity to optimize our cost expenditure, choosing and switching between various major cost items such as financial, utility and vehicle products. As System z users, we don’t have that option, only IBM provide System z servers and associated base architecture, namely the most expensive MLC software products, z/OS, CICS, DB2, IMS and WebSphere/MQ. However, just as we manage our domestic budgets, reducing power usage, optimizing vehicle TCO and getting more bang from our buck for financial products various, we can and must deliver this same due diligence for our System z MLC TCO. With industry averages of ~$500-$1000 per MSU for z/OS MLC software and associated annual expenditure measured in many millions, why wouldn’t any System z user look to deliver 10%+ cost per MSU optimization, year-on-year for their organization?

Clearly the cost of doing nothing in this instance, is significant, measured in magnitudes of millions, each and every year. Hence for System z MLC TCO optimization, looking after the Pennies is more than worthwhile, while the associated benefit of the Pounds, Euros or Dollars looking after themselves is arguably priceless.

z/OS Soft Capping: Balancing Cost & Performance

Historically each and every LPAR was assigned a Relative Weight value; where a more meaningful description would be the initial processing weight. This relative weight value is used to determine which LPAR gains access to resources, where multiple LPARs are competing for the same resource. Being unit-less is one minor challenge of the relative weight value, meaning that it has no explicit CPU capacity or resource value. Typically installations would use a simple multiple of ten metric, most likely 1000, and allocate weights accordingly (E.g. 600=60%, 300=30%, 10=10%, et al). Therefore during periods of resource contention, PR/SM would allocate resources to the requisite LPAR, based upon its relative weight.

Using relative weight to classify all LPARs as equal, at least from a generic class viewpoint, does have some considerations; primarily differentiating between Production and Non-Production workloads. Restricting a workload to its relative weight share of resources is known as Hard Capping. This setting is typically used to restrict Non-Production (E.g. Test) environments to their allocated resource and is also useful for cost control (E.g. Outsourcers), knowing that the LPAR will never consume more than its allocated relative weight allowance.

Hard Capping behaviour changes dependent on the use of the HiperDispatch setting. When HiperDispatch is not chosen, capping is performed at the Logical CP level, where the goal is for each logical CP to receive its relative CP share, based on the relative weight setting. When HiperDispatch is active, vertical as opposed to horizontal CPU management applies. So, a High categorization dictates capping at 100% of the logical CP, whereas a Medium or Low setting allows for resource sharing based on a relative weight per CP basis.

The Intelligent Resource Director (IRD) function provides more advanced relative weight management, automating management of CPU resources and a subset of I/O resources. Workload Manager (WLM) manages physical CPU resource across z/OS images within an LPAR cluster based on service class goals. IRD is implemented as a collaboration between the WLM function and the PR/SM Logical Partitioning (LPAR) hypervisor:

  • Logical CP Management: dynamically allocating logical processors (E.g. Vary On-Line/Off-Line)
  • Relative Weight Management: dynamically redistributing CPU resource as per LPAR weights
  • CHPID Management: dynamically assigning logical channel paths between eligible LPARs

IRD optimizes resource usage, enabling WLM to deliver workload goals.

The use of relative weight in association with Hard Capping and/or IRD/WLM granularity has become somewhat limited for most Mainframe installations with the advent of Sub-Capacity pricing (I.E. MLC via SCRT/R4HA). Primarily because there is no direct correlation to manage CPU resource at a meaningful level, namely the MSU (vis-à-vis CPU MIPS) metric.

Defined Capacity (DC) provides Sub-Capacity CEC pricing by allowing definition of LPAR capacity with a granularity of 1 MSU. In conjunction with the WLM function, the Defined Capacity of an LPAR dictates whether Soft Capping is invoked or not. At this juncture, we should consider how and when WLM measures CPU resource usage and if and when Soft Capping is activated and deactivated:

WLM is responsible for taking MSU utilization samples for each LPAR in 10-second intervals. Every 5 minutes, WLM documents the highest observed MSU sample value from the 10-second interval samples. This process always keeps track of the past 48 updates taken for each LPAR. When the 49th reading is taken, the 1st reading is deleted, and so on. These 48 values continually represent a total of 5 minutes * 48 readings = 240 minutes or the past 4 hours (I.E. R4HA). WLM stores the average of these 48 values in the WLM control block RCT.RCTLACS. Each time RMF (or BMC CMF equivalent) creates a Type 70 record, the SMF70LAC field represents the average of all 48 MSU values for the respective LPAR a particular Type 70 record represents. Hence, we have the “Rolling 4 Hour Average”. RMF gets the value populated in SMF70LAC from RCT.RCTLACS at the time the record is created.

SCRT also uses the Type 70 field SMF70WLA to ensure that the values recorded in SMF70LAC do not exceed the maximum available MSU capacity assigned to an LPAR. If this ever happens (due to Soft Capping or otherwise) SCRT uses the value in SMF70WLA instead of SMF70LAC. Values in SMF70WLA represent the total capacity available to the LPAR.

We should also consider the two possibilities for MLC software payment (I.E. SCRT) based upon MSU resource usage. Quite simply, the MSU value passed for SCRT invoice consideration is the R4HA or the Defined Capacity, whichever is the lowest. Put another way; if the R4HA exceeds Defined Capacity, Soft Capping applies to the LPAR.

The primary disadvantage of Soft Capping is that the Defined Capacity setting is somewhat static; it is manually defined once, maybe several times a day for workloads with distinct characteristics (E.g. On-Line, Batch, et al), but dynamic DC management based upon inter-related LPAR behaviour is at best, evolving. The primary considerations for Soft Capping are:

  • An LPAR can only be managed via Soft Capping or Hard Capping; not both
  • DC rules only applies to General Purpose CP’s (Hard Capping for Specialty Engines is allowed)
  • An LPAR must be defined with shared CP’s (dedicated CP’s not allowed)
  • All LPAR Sub-Capacity eligible products have the same MSU capacity (I.E. DC)

Soft Capping is relatively simple to implement and typically generates MLC software costs savings, with minimal impact.

Group Capacity Limit (GCL) provides an extension to the Defined Capacity (DC) Soft Capping function. GCL allows an MSU limit for total usage of all group LPARs, with a granularity of 1 MSU. The primary considerations for GCL are:

  • Works with DC LPAR capacity settings
  • Target share does not exceed DC
  • Works with IRD
  • Multiple CEC groups allowed; but an LPAR may only be defined to one group
    An LPAR must be defined with shared CP’s, with WAIT COMPLETION = NO specification

It is possible to combine IRD weight management with the GCL function. Based on installation policy, IRD can modify the relative weight setting to redistribute capacity resource within an LPAR cluster.

However, IRD weight management is suspended when GCL is in effect, because LPAR resource entitlement within a capacity group can be (I.E. Pre zxC12) derived from the current weight. Hence the LPAR might get allocated an unacceptable low weight setting, generating a low GCL entitlement.

GCL also allows for MSU to be shared between LPARs in a group, where one LPAR would be a donator and another would be a receiver. Therefore the customer classifies their LPARs accordingly and when a high-priority LPAR requires additional MSU resource, it will be allocated from a lower priority LPAR, if available. This provides a modicum of flexibility, but by definition, peak workloads are not predictable and typically require a significantly higher amount of MSU for a short time period. Typically this requirement will not be satisfied with the GCL function.

Soft Capping techniques, either at the individual (DC) or group (GCL) level deliver cost saving benefit, but a fine granularity of management is required to balance cost saving versus associated performance considerations. The primary challenges associated with Soft Capping are its interactions with workload characteristics and an inability to dynamically manage MSU allocation, in-line with the R4HA. Put another way, the R4HA is derived from 48*5 Minute samples, whereas DC and GCL settings are typically defined on an infrequent (E.g. Monthly or longer) basis.

As z/OS evolves, further in-built function is available to manage MSU capacity. zSeries Capacity Provisioning Manager (CPM) is designed to simplify the management of temporary capacity, defined capacity and group capacity. The scope of z/OS Capacity Provisioning is to address capacity requirements for relatively short term workload fluctuations for which On/Off Capacity on Demand or Soft Capping changes are applicable. CPM is not a replacement for the customer derived Capacity Management process. Capacity Provisioning should not be used for providing additional capacity to systems that have Hard Capping (initial capping or absolute capping) defined.

With the introduction of z/OS 2.1, CPM functionality incorporates Soft Capping support via the DC and GCL functions. CPM functions from a set of installation defined policies and parameters, where the CPM server receives three types of input:

  • Domain Configuration: defines the CPCs and z/OS systems to be managed
  • Policy: contains the information as to which work is eligible, for which conditions and during which timeframes and capacity increases for constrained workloads
  • Parameter: contains environment descriptors (E.g. UNIX Environment, Installation Options, et al)

From a customer viewpoint, policy definition allows them to define the provision of CPU resource:

  • Date & Time: When capacity provisioning is allowed
  • Workload: Which service class qualifies for provisioning?
  • CPU Resource: How much additional MSU capacity can be allocated?

CPM provides more function when compared with Defined Capacity and Group Capacity Limit Soft Capping techniques. Therefore allowing for time schedules to be defined, workloads to be categorized and MSU resource to be allocated in a dynamic and granular manner.

A modicum of complexity exists when considering the arguably most important factor for CPM policy definition, namely the Performance Index (PI):

  • Activation: PI of service class periods must exceed the activation threshold for a specified duration, before the work is considered as eligible.
  • Deactivation: PI of service class periods must fall below the deactivation threshold for a specified duration, before the work is considered as ineligible.
  • Null: If no workload condition is specified a scheduled activation/deactivation is performed; with full capacity as specified in the rule scope, unconditionally at the start and end times of the time condition.

For workload based provisioning it is a necessary condition that the current system Performance Index exceeds the specified customer policy PI metric. One must draw one’s own conclusions regarding PI criteria settings, but to date, they’re largely based on arguably complex mathematical formulae, which perhaps is not practicable, especially from a simple management viewpoint.

With the requisite hardware (I.E. zxC12+) and Operating System levels (I.E. z/OS 1.13+), CPM provides extra functionality for the customer to implement granular Soft Capping techniques to balance cost and performance. When compared with Defined Capacity and Group Capacity Limit techniques, CPM delivers increased granularity for managing capacity dynamically, based on customer derived policies, recognizing time slots, workloads and MSU resource increases accordingly.

From a big picture viewpoint, without doubt, we must recognize the fundamental role that WLM plays in Soft Capping. Quite simply, the 48*5 Minute MSU resource samples dictate whether a workload will be eligible for Soft Capping or not and from a cumulative viewpoint, these MSU samples dictate the R4HA metric. Based on this observation, efficient and functional Soft Capping must be workload based (I.E. WLM Service Class), be dynamic and operational on a 24*7 basis, because workload peaks are never predictable, while balancing MSU resource accordingly. Of course, simplicity of implementation and management, supplemented by meaningful reporting is mandatory.

Once again, observing the 48*5 Minute MSU resource samples from a R4HA viewpoint, if a workload was to increase MSU usage by an average of 50% for 1 Hour (I.E. 12 Samples), and decrease MSU usage by an average of 20% for 2.5 Hours (I.E. 30 Samples), from an average viewpoint, the R4HA has remained static. Therefore an optimum Soft Capping technique needs to recognize WLM service class requirements, reacting in a timely manner, increasing and decreasing MSU usage, to safeguard workload performance for Time Critical workloads, while optimizing SCRT MLC cost.

zDynaCap delivers automated capacity balancing within CPCs, Capacity Groups or Groups of LPARs. Central to zDynaCap are the predefined balancing policies. Within these balancing policies, users define their MSU ranges of Groups and LPARs and also the priorities of the associated LPAR Workload. zDynaCap continually monitors overall usage and compares this to the available capacity and the user defined MSU balancing policies. For example, should a high priority workload on one LPAR not get enough capacity, while a low priority workload on another within the group gets too much capacity, available MSU capacity is distributed according to customer derived balancing policies. Only if there is no leftover capacity to be rescheduled within the defined Group, and if the high or medium priority workload will be slowed down, will zDynaCap add MSU.

With zDynaCap Capacity Balancing, available MSU capacity is balanced within LPAR groups, safeguarding that during peak time the mission critical workload is processed as per business expectations (E.g. SLA/KPI) for the lowest possible MLC cost.

In conclusion, given the significance of IBM MLC software (E.g. z/OS, CICS, DB2, IMS, WebSphere MQ, et al) costs, arguably every Mainframe environment should deploy a capping technique for cost optimization. Hard Capping might work for some, but in all likelihood, Soft Capping is the primary choice for most Mainframe environments. For sure, IBM have delivered several Soft Capping techniques, with varying levels of function and granularity, namely Defined Capacity, Group Capacity Limit (GCL) and the zSeries Capacity Provisioning Manager (CPM). It was forever thus and the ISV community exists because they specialize, architect and deliver specialized solutions and zDynaCap is such a solution, recognizing the fundamental rules of IBM Mainframe Soft Capping, namely the underlying WLM and R4HA foundation.