Front cover How Walmart Became a Cloud Services Provider with IBM CICS Jennifer Foley Randy Frerking Mark Hollands Rich Jackson Kellie Mathis Phil Wakelin Matthew Webster Redbooks International Technical Support Organization How Walmart Became a Cloud Services Provider with IBM CICS April 2016 SG24-8347-00 Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (April 2016) This edition applies to Version 5, Release 2 of IBM CICS Transaction Server for z/OS (product number 5655-Y04). © Copyright International Business Machines Corporation 2016. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . vii Trademarks . viii IBM Redbooks promotions . ix Preface . xi Authors. xii Now you can become a published author, too! . xiii Comments welcome. xiv Stay connected to IBM Redbooks . xiv Chapter 1. Reasons to become a cloud service provider . 1 1.1 The development obstacle . 2 1.2 The developer is the consumer. 2 1.3 How z/OS and CICS are relevant to cloud . 3 1.3.1 The journey from development obstacle to cloud services . 4 1.4 Challenging the roles of IT . 6 1.5 Summary. 6 Chapter 2. The service consumer . 7 2.1 Consumer requirements . 8 2.2 Walmart caching requirement . 8 2.3 Self-service . 9 2.4 Connecting platforms . 10 2.5 CICS as a consumer . 10 2.6 Summary. 12 Chapter 3. The service provider. 13 3.1 Why Walmart chose CICS for the caching service . 14 3.1.1 Mixed language support . 14 3.1.2 Everything in the box . 14 3.1.3 Monitoring and diagnostics . 15 3.1.4 Vendor environment . 16 3.2 Foundational underpinnings . 17 3.2.1 Naming conventions . 17 3.2.2 Standards . 17 3.3 Five essential characteristics of cloud. 17 3.3.1 On-demand self-service . 18 3.3.2 Broad network access. 20 3.3.3 Resource pooling . 22 3.3.4 Rapid elasticity . 23 3.3.5 Measured service . 23 3.4 Microservices architecture . 24 3.4.1 Application design pattern. 24 3.4.2 Independent, limited function services . 24 3.4.3 Encouraged by cloud delivery model . 25 3.5 Summary. 25 © Copyright IBM Corp. 2016. All rights reserved. iii Chapter 4. The CICS systems programmer . 27 4.1 CICS architecture . 28 4.2 Service owning region. 28 4.3 CICS resource definitions . 29 4.3.1 CICS resource definitions for services . 30 4.4 Security . 34 4.4.1 SSL certificates and TCP/IP services . 35 4.4.2 Wildcard certificates and host names . 37 4.4.3 Basic authentication . 38 4.4.4 Authentication at the server level . 38 4.4.5 Authentication at the service level . 39 4.5 Multitenancy . 41 4.6 Network access. 42 4.7 Summary. 44 Chapter 5. The z/OS systems programmer. 45 5.1 Sysplex architecture . 46 5.1.1 Resource pooling, rapid elasticity, and measured service . 46 5.1.2 Unique characteristics. 46 5.1.3 Important pieces . 47 5.2 Workload manager . 47 5.2.1 LPAR weighting . 47 5.2.2 Service class. 47 5.2.3 WLM ASID weights . 48 5.3 TCP/IP. 48 5.3.1 Enabling sysplex distribution. 48 5.3.2 Establish shared ports . ..