Leveraging the IBM Z and the Z/Architecture with the IBM Ziip Specialty Engine for Mainframe FOCUS and Webfocus
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A White Paper Leveraging IBM Z and the z/Architecture with the IBM zIIP Specialty Engine for Mainframe FOCUS and WebFOCUS A Benchmark of Significant CPU Cost Reductions WebFOCUS iWay Software Omni Information Builders helps organizations transform data into business value. Our business intelligence, integration, and data integrity solutions enable smarter decision-making, strengthen customer relationships, improve performance, and drive growth. WebFOCUS iWay Software Omni Table of Contents 1 Introduction 1 Information Builders and the Z/Architecture 1 Leveraging the zIIP Specialty Engine 3 ZIIP Benchmark Tests Recap 4 Advantages of the zIIP Specialty Engine 5 Mainframe FOCUS Utilization of the zIIP 6 Is Implementing the zIIP for FOCUS Beneficial? 6 Local Adjustments That Improve zIIP Usage 7 Benchmark Tests and Statistical Rewards 8 Benchmark: Database Variations 8 Database Variations Analysis 10 Benchmark: Report Size Variations 10 Report Size Variations Analysis 11 Benchmark: Typical Application Activities 12 Typical Application Activities Analysis 13 Conclusion 14 Appendix I 14 zIIP Usage Statistics 15 Appendix II 15 IBM Workload Manager Tuning 16 Appendix III 16 Glossary Introduction Information Builders and the z/Architecture According to an IDC White Paper, sponsored by CA Technologies and IBM, “The Business Value of the Connected Mainframe for Digital Transformation,”1 the mainframe is at an inflection point from being a supporting platform of transaction revenue to becoming a source of revenue growth and innovation”. Information Builders FOCUS (Mainframe) and WebFOCUS products have been architected to take advantage of IBMs constantly evolving mainframe z/Architecture. First introduced in 2000, this z/Architecture is now the foundation of the IBM Z Systems family of mainframes., named for their most salient characteristic – “availability” – the ‘Z’ standing for zero downtime. The z/OS is the 64-bit operating system that supports this z/Architecture across the z System family. Each z/OS leverages the z/Architecture and can address a 64-bit address space as well as support real and virtual spaces of 16 exabytes! The IBM Z family also supports the System z Integrated Information Processor (zIIP) processor. This processor was designed to operate asynchronously with general processors to help improve utilization of computing capacity and control costs by offloading CPU-intensive work. The System z includes the newly introduced mainframe the z14, introduced in Q2 2017, and the z13 first introduced in 2015. Both of these systems can be upgraded to take advantage of the zIIP Processor. Most importantly, FOCUS and WebFOCUS can take advantage of the z/Architecture, it can take advantage of underlying z/OS, and zIIP processor across the entire System z family including the current z13 and the new z14. Leveraging the zIIP Specialty Engine Mainframe FOCUS* and WebFOCUS can both leverage the system z Integrated Information Processor (zIIP) engine. This white paper demonstrates the types and approximate amounts of FOCUS workload transferred to the zIIP under various conditions, and the resulting cost reductions. The zIIP specialty engine from IBM offloads CPU-intensive workloads from the central processors (CPs). Since the MIPS capacity of the zIIP engine is not included in the overall rating of the mainframe, all work incurred using the zIIP engine is free from IBM. Installing a zIIP can be a way to delay a system upgrade. It may also be a performance enhancer for products enabled to run there and for the overall system. About 80 percent of FOCUS code is able to run on the zIIP, which accounts for as much as 95 percent of CPU capacity, though it will more generally be in the 30 to 80 percent range. These estimates are above the already documented 20 to 40 percent performance improvement of Release 7.6 and 7.7x over prior releases due to our continuous improvement program using all 1 “The Business Value of the Connected Mainframe for Digital Transformation,” IDC, December 2016. * Current Mainframe FOCUS releases are 7.6.13, 7.7.03M and 7.7.06M with 7707M anticipated in 2018. 1 Information Builders of the newer technologies available. During the zIIP enablement development effort, all of the technical and legal implementation restrictions imposed by IBM were rigorously respected. Some internal processes must continue to run on the central processor due to IBM specifications regarding the types of workload the zIIP may process. Productive zIIP activity is monitored by FOCUS, and FOCUS reacts accordingly to ensure that IBM-billable CPU charges are minimized against zIIP-related overhead. The actual amount of processing diverted to the zIIP is largely dependent on the goal settings declared locally to the IBM Workload Manager (WLM), which specifies the priority of FOCUS access to the zIIP in competition with other software. FOCUS provides methods for the user to query zIIP- related CPU information and improve zIIP-related processing. There are also techniques available to adjust the application to best take advantage of the zIIP engine when running FOCUS. If you do not have a feel for how much a zIIP engine installed at your site can reduce the cost of FOCUS processing, you may simulate the presence of a zIIP engine if none exists, or you may simulate giving full access to FOCUS processing on an existing zIIP. System statistics will then tell you how FOCUS would perform with full zIIP advantage. As mentioned above, WebFOCUS also makes use of the zIIP engine for Java™ processing, which is not covered in this white paper. Contact an Information Builders representative for more information. 2 Leveraging IBM Z and the z/Architecture with the IBM zIIP Specialty Engine zIIP Benchmark Tests Recap Information Builders designed benchmark tests to evaluate the amount of workload transferred to the zIIP under specific conditions and test scenarios. The results summarize as follows: DB2 results vary, depending upon the local configuration of FOCUS and DB2. CPU Savings Type of Report or Activity Using zIIP Interpretation Executive Summary Report 77% Roll-up, out to PDF Operational Report 64% Medium size Extract Report 66% Show 100% of file Exception Report 51% Extract a few records Database Type Variations 1-88% Various sort methods and destinations** Reporting Scenarios 59-99% One million records, various complexities Transaction Processing 42-95% One million records, load, update, etc. Actual Applications 46% Weighted average of five applications’ usage Performance Benchmarks 76% Weighted average of targeted internal processes ** Several database types generate low zIIP advantage due to imposed record retrieval methods. 3 Information Builders Advantages of the zIIP Specialty Engine IBM’s zIIP specialty engine is one of several specialty engines that IBM has implemented for mainframe consumption. The zIIP engine offloads Java™ workload and specific CP-intensive workload. The MIPS capacity of the zIIP engine does not count toward the overall MIPS rating of the mainframe image, so all CPU usage incurred on the zIIP is not chargeable from IBM. Effectively, all workload run on the zIIP is free. The zIIP engine is factory-identical to a central processor (CP). It is restricted at installation time via micro-code to perform specific types of workloads, but always runs at 100 percent of processor capacity. The zIIP offloads heavily CPU-intensive workloads, leaving the CP more time to absorb otherwise queued workloads as well as to perform its dedicated tasks of running the operating system, handling I/O interrupts and timer interrupts, initiating jobs, and controlling user interactions with the operating system. Therefore, some overall performance improvement can be perceived across all mainframe activity. The true benefit of the zIIP is its cost reduction effect and its potential contribution to delaying a system upgrade. The actual zIIP benefit achieved for FOCUS, WebFOCUS, or any product depends on the response time goals declared by the local system administrator to the WLM when defining the priority of the software’s access to the zIIP in competition with other software. 4 Leveraging IBM Z and the z/Architecture with the IBM zIIP Specialty Engine Mainframe FOCUS Utilization of the zIIP Beginning with FOCUS 7.6.10, the zIIP engine has been accessible to FOCUS for processing much of the typical workload associated with a FOCUS request. zIIP activation begins upon user issuance of a SET command if all applicable conditions for zIIP use pass properly. If the zIIP is not available to the lpar, then processing simply continues on the CP; FOCUS continues to run. (See the Benchmark Statistics section of this white paper that examines the gains achievable by use of the zIIP.) FOCUS diverts eligible workload to the zIIP by switching from TCB mode (for instructions that can run only on the central processor) to SRB mode that engages a preemptible enclave for secure execution of enabled workloads on the zIIP engine. Though a large percentage of the workload is eligible for execution on the zIIP, the actual amount permitted to run on the zIIP at any moment (therefore the benefit achieved for the FOCUS user) largely depends on the response time goals declared in the WLM by the local system administrator. (See the IBM Workload Manager appendix.) During the zIIP development effort, all of the technical and legal implementation restrictions imposed by IBM were rigorously respected. The major factor that affects zIIP’s performance is IBM’s restriction that the zIIP does not handle I/O interrupts. In applications that require significant database interrogation, high-volume sorting, or the use of third-party tools or user functions during processing (most of which are present in typical applications), passing information among these environments requires switching out of SRB (zIIP) mode into TCB (non-zIIP) mode to communicate, and then back again to continue processing. This switching can occur thousands or even millions of times during a single request.