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Scaling the Sysplex on IBM Z

An IBM Redbooks course


First available 11 September 2018


This video series describes how one IBM client, Walmart, is utilizing IBM CICS and the IBM Coupling Facility in innovative and modern ways. The video series combines real-world examples from Walmart along with guidance and advice for creating your own solutions. You will learn how to perform new functions and have these functions benefit from the scalability and availability achieved only in a mainframe ecosystem. This video series is a companion to the IBM Redbooks publication IBM CICS and the Coupling Facility: Beyond the Basics.

  • This video series is of interest to anybody interested in how features of the IBM Z sysplex can be used to scale high volumes of daily workload. 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.

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      Chapter  01

      How CICS exploit the CICS Coupling Facility

      This chapter introduces the video course.

      Section 1: Understanding how Walmart exploit the CICS Coupling Facility (1 mins 31 secs)

      In 10 years Walmart has scaled from processing about 200 million CICS transactions per day in 2007 to 700 million daily CICS transactions today. This section briefly describes their evolution and how they are scaling this workload through innovate uses of the Coupling Facility.

      Chapter  02

      VSAM Record Level Sharing

      This chapter provides a high-level overview of the VSAM RLS function and its uses.

      Section 1: VSAM Record Level Sharing (1 mins 57 secs)

      This section addresses general uses of VSAM RLS in CICS, along with high level guidance on setting up and using VSAM RLS in CICS.

      Chapter  03

      Named Counters

      This chapter provides an overview of named counters and how to use them effectively.

      Section 1: Common uses (2 mins 15 secs)

      Named counters are frequently used by applications that run in a sysplex environment because they are efficient and universally accessible. This section summarizes the steps that are required to set up a named counter server and to update CICS to access the server.

      Section 2: Examples: Generating a unique ID and components of keys (4 mins 03 secs)

      This section illustrates two scenarios where named counters are used to address real-world needs: for generating a unique ID, and generating components of keys.

      Section 3: Examples: Distributing workload and tracking activity (4 mins 40 secs)

      This section illustrates two additional scenarios where named counters are used to address real-world needs: to distribute workload, and to track activity.

      Chapter  04

      Global Resource Serialization

      This chapter outlines how Global Resource Serialization (GRS) is achieved in CICS and shows examples of its use by tasks that are running in a sysplex environment.

      Section 1: Common uses (3 mins 11 secs)

      A CICS global enqueue is frequently used by CICS applications that execute in multiple CICS regions to complete tasks such as serialization of updating a common resource, and synchronizing an activity over multiple regions. This section summarizes the steps that are required to set up global enqueues in CICS.

      Section 2: Example use cases (4 mins 44 secs)

      This section delves into some applicable examples of using global enqueues to improve or expand on current capabilities. It describes uses cases for global transaction class, serialization for dispatched tasks, and enqueue list.

      Chapter  05

      Coupling Facility Data Tables

      This chapter provides an overview of coupling facility data tables (CFDTs).

      Section 1: Common uses (2 mins 13 secs)

      CFDTs provide a method of file data sharing, using CICS file control, without the need for a file owning region (FOR) and without the need for Virtual Storage Access Method (VSAM) record-level sharing (RLS) support. CFDTs are typically used for a scratch pad for in-memory objects, and sharing of commonly-used dynamic data that must be consistent across regions. This section summarizes the steps that are required to set up CFDTs.

      Section 2: Example use cases (4 mins 31 secs)

      This section explore ways that you can use the CFDT beneficially, with the assumption that the data formats that are associated with the workload are within the confines of the stated CFDT restrictions. It addresses caching information, logging work items, and flexibility for data stores.

      Chapter  06

      Shared Temporary Storage

      Temporary storage (TS) is the primary CICS facility for storing data that must be available to multiple transactions. This chapter concentrates on shared temporary storage, which is accessible by CICS regions anywhere within a sysplex.

      Section 1: Common uses (3 mins 12 secs)

      Shared TS is frequently used to share data between applications that are hosted within multiple CICS regions in a sysplex. TS common uses include shopping baskets, history of actions performed by a task or series of tasks, and synchronization of asynchronous activities within one or more CICS regions. This section summarizes the steps that are required to set up shared temporary storage.

      Section 2: Example use cases (2 mins 04 secs)

      This section describes some real-world use cases of using shared TS queues. It addresses adjusting priority based on HTTP method, and sharing data among tasks.

      Chapter  07

      Combined Functional Use

      This chapter shows how the various features described in this video series can be combined together to tackle a few assorted challenges.

      Section 1: Combined functional use (2 mins 38 secs)

      This section addresses two examples of combining the various functions discussed in this video series: sequencing captured updates for data synchronization, and processing one-to-many parallel requests.