Front cover Getting Started with IBM Z Resiliency Bill White Marc Coq Pabitra Mukhopadhyay Carlos Alberto Pistillo David Raften Mai Zeng Redbooks IBM Redbooks Getting Started with IBM Z Resiliency March 2020 SG24-8446-00 Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (March 2020) © Copyright International Business Machines Corporation 2020. 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 Preface . ix Authors. ix Now you can become a published author, too! . .x Comments welcome. .x Stay connected to IBM Redbooks . xi Chapter 1. Resiliency is key to the survival of a digital business . 1 1.1 What’s the cost of downtime . 2 1.1.1 Fixed costs . 2 1.1.2 Lost revenue . 3 1.1.3 Intangible costs . 3 1.1.4 Balancing IT risk and costs of mitigation. 4 1.2 Measuring availability . 4 1.2.1 Availability objectives . 5 1.2.2 Recovery objectives: RPO and RTO. 6 1.2.3 Aspects of availability . 7 1.3 A path to higher availability . 9 1.3.1 Model 1: Starting with a resilient and reliable base. 10 1.3.2 Model 2: Reducing the duration of outages with failover capability . 11 1.3.3 Model 3: Reducing the impact of outages with a fault tolerant architecture and GDPS. 12 1.3.4 Model 4: Adding GDPS Continuous Availability for maximal resilience . 13 Chapter 2. Resiliency is built into the IBM Z platform . 15 2.1 Why redundancy and RAS . 16 2.2 Infrastructure layer . 17 2.2.1 Compute . 17 2.2.2 Storage . 22 2.2.3 Network. 24 2.2.4 Virtualization . 25 2.2.5 Range of resiliency for IBM Z environments . 27 2.3 Operating system layer . 31 2.3.1 z/OS . 32 2.4 Middleware layer . 39 2.4.1 IBM MQ for z/OS. 39 2.4.2 IBM Db2 for z/OS . 42 2.5 Application layer . 45 2.5.1 Customer Information Control System . 46 2.5.2 Information Management System . 62 2.5.3 IBM WebSphere Application Server for z/OS . 73 2.5.4 Batch processing . 78 2.6 Management layer . 81 2.6.1 IBM System Automation for z/OS . 82 2.6.2 IBM Z Operations Analytics (IZOA). 84 2.6.3 IBM OMEGAMON product family . 85 2.6.4 CICS tools. 85 © Copyright IBM Corp. 2020. All rights reserved. iii 2.6.5 IMS tools . 86 Chapter 3. IBM Z resiliency models. 93 3.1 Model 1: Starting with a resilient and reliable base. 94 3.1.1 Description . 94 3.1.2 Considerations . 94 3.1.3 Use case: planned outage . 95 3.1.4 Use case: unplanned / unexpected outages. 96 3.1.5 Resiliency optimization and next steps . 96 3.2 Model 2: Reducing the duration of outages with failover capability . 97 3.2.1 Parallel Sysplex Resource Sharing. 97 3.2.2 Description . 97 3.2.3 Considerations . 98 3.2.4 Use case: planned outage . 98 3.2.5 Use case: unplanned outage . 99 3.2.6 Resiliency optimization and next steps . 100 3.3 Model 3: Reducing the impact of outages with a fault tolerant architecture and GDPS . 101 3.3.1 Description . 101 3.3.2 Considerations . 101 3.3.3 Multi-site workload configuration. 103 3.3.4 Use case: planned outage . 104 3.3.5 Use case: unplanned outage . 104 3.3.6 Resiliency optimization and next steps . 105 3.4 Model 4: Adding GDPS Continuous Availability for maximal resilience . 106 3.4.1 Description . 106 3.4.2 Considerations . 108 3.4.3 Use case: planned outage . ..