Virtual Storage Access Method (VSAM) is one of the access methods used to process data. Many of us have used VSAM and work with VSAM data sets daily, but exactly how it works and why we use it instead of another access method is a mystery. This book helps to demystify VSAM and gives you the information necessary to understand, evaluate, and use VSAM properly. This book also builds upon the subject of Record Level Sharing and DFSMStvs. It clarifies VSAM functions for application programmers who work with VSAM. The practical, straightforward approach should dispel much of the complexity associated with VSAM. Wherever possible an example is used to reinforce a description of a VSAM function. This IBM® Redbooks® publication is intended as a supplement to existing product manuals. It is intended to be used as an initial point of reference for VSAM functions.

It's easy to look at the title of a book and think "that's old news" or "I already know all there is to know on that subject." But before you dismiss this publication, consider just how far the IBM® Parallel Sysplex® architecture has come. From the early days the mainframe has embraced a shared everything approach. The original designers coded IBM z/OS® (called IBM MVSTM or IBM OS/390® back then) with the functionality necessary for the operating system to create the repositories, manage the data flow, and ensure the integrity of the systems involved. From there, the middleware systems provided the exploitation and advanced functions to mature the technology. The component in the middle of all this great technology can easily be taken for granted. That is the IBM Coupling Facility. This IBM Redbooks® publication discusses both traditional uses for the IBM Coupling Facility technology and new ways to use it with products such as IBM CICS®. You can learn how to perform new functions and have these functions benefit from the scalability and availability achieved only in a mainframe ecosystem. Open standards are a large part of considerations today, as most companies run IT shops with a mix of technology components. As the world embraces these technologies, it is necessary to understand how to mix the world of mainframe architectures and products with other open architectures. This mix allows the best tool to be used to solve processing needs, at the right cost and service levels. Often the functions needed for modern processing can be found in house, in places where staff are skilled and that already deliver the robust production environments you count on daily. This book discusses these modern functions and how to achieve them with CICS use of the IBM Coupling Facility. You will learn how one IBM client, Walmart, took these concepts far beyond the original design as they share their experiences and even share code examples to help you get started. The last chapter of this book shows what can be achieved when a combination of old and new functions are use together. Even if you have familiarity with what could be done with the IBM Coupling Facility in the past, there is much to learn and deploy in a modern world. Those who are familiar with the IBM Coupling Facility might find the content of this book helpful. Additionally, readers who are considering how to use the IBM Coupling Facility technology within their environment might also find useful information in the chapters that follow

In this IBM® Redbooks® publication, we discuss CICS®, which stands for Customer Information Control System. It is a general-purpose transaction processing subsystem for the z/OS® operating system. CICS provides services for running an application online where, users submit requests to run applications simultaneously. CICS manages sharing resources, the integrity of data, and prioritizes execution with fast response. CICS authorizes users, allocates resources (real storage and cycles), and passes on database requests by the application to the appropriate database manager, such as DB2®. We review the history of CICS and why it was created. We review the CICS architecture and discuss how to create an application in CICS. CICS provides a secure, transactional environment for applications that are written in several languages. We discuss the CICS-supported languages and each language's advantages in this Redbooks publication. We analyze situations from a system programmer's viewpoint, including how the systems programmer can use CICS facilities and services to customize the system, design CICS for recovery, and manage performance. CICS Data access and where the data is stored, including Temporary storage queues, VSAM RLS, DB2, IMSTM, and many others are also discussed.

IBM® CICS® Transaction Server (CICS TS) has been available in various guises for over 40 years, and continues to be one of the most widely used pieces of commercial software. This IBM Redbooks® publication helps application architects discover the value of CICS Transaction Server to their business. This book can help architects understand the value and capabilities of CICS Transaction Server and the CICS tools portfolio. The book also provides detailed guidance on the leading practices for designing and integrating CICS applications within an enterprise, and the patterns and techniques you can use to create CICS systems that provide the qualities of service that your business requires.

The ABCs of IBM z/OS® System Programming is a 13-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 that you need to start your research into z/OS and related subjects. The ABCs collection serves as a powerful technical tool to help you become more familiar with z/OS in your current environment, or to help you evaluate platforms to consolidate your e-business applications. This edition is updated to z/OS Version 2 Release 3. The other volumes contain the following content: 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, IBM Job Entry Subsystem 2 (JES2) and JES3, link pack area (LPA), LNKLST, authorized libraries, System Modification Program Extended (SMP/E), IBM Language Environment Volume 4: Communication Server, TCP/IP, and IBM VTAM® Volume 5: Base and IBM Parallel Sysplex®, System Logger, Resource Recovery Services (RRS), global resource serialization (GRS), z/OS system operations, automatic restart manager (ARM), IBM Geographically Dispersed Parallel SysplexTM (IBM GDPS) Volume 6: Introduction to security, IBM RACF®, Digital certificates and PKI, Kerberos, cryptography and z990 integrated cryptography, zSeries firewall technologies, LDAP, and Enterprise Identity Mapping (EIM) 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 IBM z/Architecture®, the IBM Z platform, IBM Z connectivity, LPAR concepts, HCD, and DS Storage Solution. Volume 11: Capacity planning, performance management, WLM, IBM RMFTM, and SMF Volume 12: WLM Volume 13: JES3, JES3 SDSF

Significant performance benefits can be realized by increasing the amount of memory that is assigned to various functions in the IBM® z/OS® software stack, operating system, and middleware products. IBM DB2® and IBM MQ buffer pools, dump services, and large page usage are just a few of the functions whose ease of use and performance can be improved when more memory is made available to them. The following benefits can realized: Reduced I/O operations Reduced CPU usage Improved transaction response time Potential cost reductions Although the magnitude of these improvements can vary widely based on several factors, including potential I/Os to be eliminated, resource contention, workload, configuration, and tuning, clients must carefully consider whether their environment can benefit from the addition of memory to the software functions that are described in this IBM RedpaperTM publication. This paper describes the performance implications of increasing memory in the following areas: DB2 buffer pools DB2 tuning IBM Cognos® Dynamic Cubes MDM with larger DB2 buffer pools Java heaps and Garbage Collection tuning and Java large page use MQ v8 64-bit buffer pool tuning Enabling more in-memory use by IBM CICS® without paging TCP/IP FTP DFSort I/O reduction Fixed pages and fixed large pages

Beginning with IBM® CICS® Version 2, applications can run on TCBs apart from the QR TCB, which has positive implications for improving system throughput and for implementing new technologies inside of CICS. Examples of implementing new technologies include using the IBM MVSTM Java virtual machine (JVM) inside CICS and enabling listener tasks written for other platforms to be imported to run under CICS. The newest release, CICS Transaction Server for z/OS® (CICS TS) V4.2, includes scalability enhancements so that you can perform more work more quickly in a single CICS system. The advantage of this enhancement is that you can increase vertical scaling and decrease the need to scale horizontally, reducing the number of regions that are required to run the production business applications. The scalability enhancements in CICS TS V4.2 fall into two broad areas, which are increased usage of open transaction environment (OTE) and of 64-bit storage. This IBM Redbooks® publication is a comprehensive guide to threadsafe concepts and implementation for IBM CICS. This book explains how systems programmers, applications developers, and architects can implement threadsafe applications in an environment. It describes the real-world experiences of users, and our own experiences, of migrating applications to be threadsafe. This book also highlights the two most critical aspects of threadsafe applications: system performance and integrity.

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.

This IBM® Redbooks® publication discusses practical uses of the IBM CICS asynchronous API capability. It describes the methodology, design and thought process used by a large client, Walmart, and the considerations of the choices made. The Redbooks publication provides real life examples and application patterns that benefit from the performance and scalability offered by the new API. The book discusses the homegrown methodology used by Walmart before the API was available and compares it with the design using the new API. A discussion of the process used to migrate older applications to begin using the new API is included so the reader will understand the ease of implementing the new API. A description of real world usage patterns describes the current production application Walmart has deployed as well as other patterns to give the reader a sense of what's possible applying creative thinking with technology improvements. Finally, a section is included on the areas to be considered as you begin to plan and implement asynchronous API capabilities. This book should be read by: Enterprise Architects searching for faster ways to service strategic applications across the enterprise. Solution Architects who want to better understand implementation possibilities for improved response times and better performance for CICS applications. CICS programmers looking to modernize and provide improved response times. This book is meant to be used in tandem with IBM Redbooks publication IBM CICS Asynchronous API: Concurrent Processing Made Simple, SG24-8411, which will provide the background and implementation instructions and commands for the API itself.

This IBM® Redpaper Redbooks® publication introduces the IBM System z® New Application License Charges (zNALC) pricing structure and provides examples of zNALC workload scenarios. It describes the products that can be run on a zNALC logical partition (LPAR), reasons to consider such an implementation, and covers the following topics: Using the IBM WebSphere Application Server Liberty profile to host applications within an IBM CICS® environment and how it interacts with CICS applications and resources Security technologies available to applications that are hosted within a WebSphere Application Server Liberty profile in CICS How to implement modern presentation in CICS with a CICS Liberty Java virtual machine (JVM) server How to share scenarios to develop Liberty JVM applications to gain benefits from IBM CICS Transaction Server for IBM z/OS® Value Unit Edition Considerations when using mobile devices to interact with CICS applications and explains specific CICS technologies for connecting mobile devices by using the z/OS Value Unit Edition How IBM Operational Decision Manager for z/OS runs in the transaction server to provide decision management services for CICS COBOL and PL/I applications Installing the CICS Transaction Server for z/OS (CICS TS) Feature Pack for Modern Batch to enable the IBM WebSphere® batch environment to schedule and manage batch applications in CICS This book also covers what is commonly referred to as plain old Java objects (POJOs). The Java virtual machine (JVM) server is a full-fledged JVM that includes support for Open Service Gateway initiative (OSGi) bundles. It can be used to host open source Java frameworks and does just about anything you want to do with Java on the mainframe. POJO applications can also qualify for deployment using the Value Unit Edition. Read about how to configure and deploy them in this companion Redbooks publication: IBM CICS and the JVM server: Developing and Deploying Java Applications, SG24-8038 Examples of POJOs are terminal-initiated transactions, CICS web support, web services, requests received via IP CICS sockets, and messages coming in via IBM WebSphere MQ messaging software.