Optimizing System Z Batch Applications By Exploiting Parallelism

This IBM® RedpaperTM publication shows you how to speed up batch jobs by splitting them into near-identical instances (sometimes referred to as ). It is a practical guide, which is based on the authors' testing experiences with a batch job that is similar to those jobs that are found in customer applications. This guide documents the issues that the team encountered and how the issues were resolved. The final tuned implementation produced better results than the initial traditional implementation. Because job splitting often requires application code changes, this guide includes a description of some aspects of application modernization you might consider if you must modify your application. The authors mirror the intended audience for this paper because they are specialists in IBM DB2®, IBM Tivoli® Workload Scheduler for z/OS®, and z/OS batch performance.

Batch performance optimization remains an important topic for many companies today, whether merging workloads, supporting growth, reducing cost or extending the online day. This IBM® RedpaperTM publication describes a general approach that can be used to optimize the batch window in a z/OS® environment. This paper outlines a structured methodology using anti-patterns and tools that can be followed to increase batch productivity.

Mainframe computers play a central role in the daily operations of many of the world's largest corporations, and batch processing is a fundamental part of the workloads that run on the mainframe. A large portion of the workload on IBM® z/OS® systems is processed in batch mode. Although several IBM Redbooks® publications discuss application modernization on the IBM z/OS platform, this book specifically addresses batch processing in detail. Many different technologies are available in a batch environment on z/OS systems. This book demonstrates these technologies and shows how the z/OS system offers a sophisticated environment for batch. In this practical book, we discuss a variety of themes that are of importance for batch workloads on z/OS systems and offer examples that you can try on your own system. The audience for this book includes IT architects and application developers, with a focus on batch processing on the z/OS platform.

This IBM® Redbooks® publication pulls together diverse information regarding the best way to design, implement, and manage a Parallel Sysplex® to deliver the levels of performance and availability required by your organization. This book should be of interest to system programmers, availability managers, and database administrators who are interested in verifying that your systems conform to IBM best practices for a Parallel Sysplex environment. In addition to z/OS® and the sysplex hardware configuration, this book also covers the major IBM subsystems: CICS® DB2® IMSTM MQ WebSphere® Application Server To get the best value from this book, readers should have hands-on experience with Parallel Sysplex and have working knowledge of how your systems are set up and why they were set up in that manner.

The ABCs of z/OS® System Programming is an eleven-volume collection that provides an introduction to the z/OS operating system and the hardware architecture. Whether you are a beginner or an experienced system programmer, the ABCs collection provides the information you need to start your research into z/OS and related subjects. If you would like to become more familiar with z/OS in your current environment, or if you are evaluating platforms to consolidate your e-business applications, the ABCs collection will serve as a powerful learning tool. The contents of the volumes are: Volume 1: Introduction to z/OS and storage concepts, TSO/E, ISPF, JCL, SDSF, and z/OS delivery and installation Volume 2: z/OS implementation and daily maintenance, defining subsystems, JES2 and JES3, LPA, LNKLST, authorized libraries, Language Environment®, and SMP/E Volume 3: Introduction to DFSMS, data set basics, storage management hardware and software, VSAM, System-Managed Storage, catalogs, and DFSMStvs Volume 4: Communication Server, TCP/IP and VTAM® Volume 5: Base and Parallel Sysplex®, System Logger, Resource Recovery Services (RRS), global resource serialization (GRS), z/OS system operations, Automatic Restart Management (ARM), Geographically Dispersed Parallel SysplexTM (GPDS), availability in the zSeries® environment Volume 6: Introduction to security, RACF®, Digital certificates and PKI, Kerberos, cryptography and z990 integrated cryptography, zSeries firewall technologies, LDAP, Enterprise identity mapping (EIM), and firewall technologies Volume 7: Printing in a z/OS environment, Infoprint Server and Infoprint Central Volume 8: An introduction to z/OS problem diagnosis Volume 9: z/OS UNIX® System Services Volume 10: Introduction to z/Architecture®, zSeries processor design, zSeries connectivity, LPAR concepts, HCD, and HMC Volume 11: Capacity planning, performance management, RMF, and SMF Volume 12: WLM Volume 13: JES3

There has been a considerable focus on performance improvements as one of the main themes in recent IBM DB2® releases, and DB2 12 for IBM z/OS® is certainly no exception. With the high-value data retained on DB2 for z/OS and the z Systems platform, customers are increasingly attempting to extract value from that data for competitive advantage. Although customers have historically moved data off platform to gain insight, the landscape has changed significantly and allowed z Systems to again converge operational systems with analytics for real-time insight. Business-critical analytics is now requiring the same levels of service as expected for operational systems, and real-time or near real-time currency of data is expected. Hence the resurgence of z Systems. As a precursor to this shift, IDAA brought the data warehouse back to DB2 for z/OS and, with its tight integration with DB2, significantly reduces data latency as compared to the ETL processing that is involved with moving data to a stand-alone data warehouse environment. That change has opened up new opportunities for operational systems to extend the breadth of analytics processing without affecting the mission-critical system and integrating near real-time analytics within that system, all while maintaining the same z Systems qualities of service. Apache Spark on z/OS and Linux for System z also allow analytics in-place, in real-time or near real-time. Enabling Spark natively on z Systems reduces the security risk of multiple copies of the Enterprise data, while providing an application developer-friendly platform for faster insight in a simplified and more secure analytics framework. How is all of this relevant to DB2 for z/OS? Given that z Systems is proving again to be the core Enterprise Hybrid Transactional/Analytical Processing (HTAP) system, it is critical that DB2 for z/OS can handle its traditional transactional applications and address the requirements for analytics processing that might not be candidates for these rapidly evolving targeted analytics systems. And not only are there opportunities for DB2 for z/OS to play an increasing role in analytics, the complexity of the transactional systems is increasing. Analytics is being integrated within the scope of those transactions. DB2 12 for z/OS has targeted performance to increase the success of new application deployments and integration of analytics to ensure that we keep pace with the rapid evolution of IDAA and Spark as equal partners in HTAP systems. This paper describes the enhancements delivered specifically by the query processing engine of DB2. This engine is generally called the optimizer or the Relational Data Services (RDS) components, which encompasses the query transformation, access path selection, run time, and parallelism. DB2 12 for z/OS also delivers improvements targeted at OLTP applications, which are the realm of the Data Manager, Index Manager, and Buffer Manager components (to name a few), and are not identified here. Although the performance measurement focus is based on reducing CPU, improvement in elapsed time is likely to be similarly achieved as CPU is reduced and performance constraints alleviated. However, elapsed time improvements can be achieved with parallelism, and DB2 12 does increase the percentage offload for parallel child tasks, which can further reduce chargeable CPU for analytics workloads.

In a smarter planet, information-centric processes are exploding in growth. The mainframe has always been the IT industry's leading platform for transaction processing, consolidated and secure data serving, and support for available enterprise-wide applications. IBM® has extended the mainframe platform to help large enterprises reshape their client experiences through information-centric computing and to deliver on key business initiatives. IBM zEnterprise® is recognized as the most reliable and trusted system, and the most secure environment for core business operations. The new zEnterprise System consists of the IBM zEnterprise EC12 (zEC12) or IBM zEnterprise BC12 (zBC12), the IBM zEnterprise Unified Resource Manager, and the IBM zEnterprise IBM BladeCenter® Extension (zBX) Model 003. This IBM Redbooks® publication describes the zEC12 and zBC12, with their improved scalability, performance, security, resiliency, availability, and virtualization. The zEnterprise System has no peer as a trusted platform that also provides the most efficient transaction processing and database management. With efficiency at scale delivering significant cost savings on core processes, resources can be freed up to focus on developing new services to drive growth. This book provides a technical overview of the zEC12, zBC12, zBX Model 003, and Unified Resource Manager. This publication is intended for IT managers, architects, consultants, and anyone else who wants to understand the elements of the zEnterprise System. For this introduction to the zEnterprise System, readers are not expected to be familiar with current IBM System z® technology and terminology.

The z/OS System Logger is a function provided by the operating system to exploiters running on z/OS. The number of exploiters of this component is increasing, as is its importance in relation to system performance and availability. This IBM Redbooks document provides system programmers with a solid understanding of the System Logger component and guidance about how it should be set up for optimum performance with each of the exploiters. System Logger is an MVS component that provides a logging facility for applications running in a single-system or multi-system sysplex. The advantage of using System Logger is that the responsibility for tasks such as saving the log data (with the requested persistence), retrieving the data (potentially from any system in the sysplex), archiving the data, and expiring the data is removed from the creator of the log records. In addition, Logger provides the ability to have a single, merged, log, containing log data from multiple instances of an application within the sysplex.