OS/390 Parallel Sysplex Configuration Volume 1: Overview Frank Kyne, Luiz Fadel, Michael Ferguson, Rafael Garcia, Keith George, Masayuki Kojima, Alan Murphy, Henrik Thorsen International Technical Support Organization www.redbooks.ibm.com SG24-5637-00 International Technical Support Organization SG24-5637-00 OS/390 Parallel Sysplex Configuration Volume 1: Overview August 2000 Take Note! Before using this information and the product it supports, be sure to read the general information in Appendix A, “Special Notices” on page 233. First Edition (August 2000) This edition applies to Program Name, Program Number Version, Release Number CICS/ESA, 5655-018 4.1 CICS TS for OS/390, 5655-147 1.3 DB2 for OS/390, 5655-DB2 5.1 DB2 UDB for OS/390, 5645-DB2 6.1 DB2 UDB for OS/390, 5675-DB2 7.1 DFSMS/MVS, 5695-DF1 1.5 IMS/ESA, 5695-176 5.1 IMS/ESA, 5655-158 6.1 IMS/ESA, 5655-B01 7.1 System Automation for OS/390, 5645-045 1.3 for use with: Program Name Version, Release Number OS/390, 5645-001 1.3 OS/390, 5647-A01 2.4 OS/390, 5647-A01 2.5 OS/390, 5647-A01 2.6 OS/390, 5647-A01 2.7 OS/390, 5647-A01 2.8 OS/390, 5647-A01 2.9 OS/390, 5647-A01 2.10 Comments may be addressed to: IBM Corporation, International Technical Support Organization Dept. HYJ Mail Station P099 2455 South Road Poughkeepsie, New York 12601-5400 When you send information to IBM, you grant IBM a non-exclusive right to use or distribute the information in any way it believes appropriate without incurring any obligation to you. Copyright International Business Machines Corporation 2000. All rights reserved. Note to U.S. Government Users —Documentation related to restricted rights —Use, duplication or disclosure is subject to restrictions set forth in GSA ADP Schedule Contract with IBM Corp. Contents Figures .......................................... xiii OS/390 Parallel Sysplex Configuration Volume 1: Overview .......... xiii OS/390 Parallel Sysplex Configuration Volume 2: Cookbook .......... xiv OS/390 Parallel Sysplex Configuration Volume 3: Connectivity ........ xiv Tables .......................................... xvii OS/390 Parallel Sysplex Configuration Volume 1: Overview .......... xvii OS/390 Parallel Sysplex Configuration Volume 2: Cookbook .......... xvii OS/390 Parallel Sysplex Configuration Volume 3: Connectivity ....... xviii Preface ......................................... xix The Team That Wrote These Redbooks ...................... xix Comments Welcome ................................. xxx OS/390 Parallel Sysplex Configuration Volume 1: Overview 1.0 Introduction to the Configuration of a Parallel Sysplex ............ 1 1.1 How to Use These Redbooks - Read This First ................ 1 1.2 The Purpose of These Books ........................... 5 1.3 Base Hardware Levels for These Books .................... 6 1.4 Main Reasons for Parallel Sysplex ....................... 6 1.4.1 Continuous Application Availability .................... 7 1.4.2 Workload Balancing .............................. 8 1.4.3 Nondisruptive Addition of Scalable CPC Capacity ............ 8 1.4.4 Reduced Total Cost of Computing ..................... 10 1.4.5 Single System Image ............................. 12 1.5 Value of Parallel Sysplex - A Summary ..................... 13 1.6 The Distinction between Basic and Parallel Sysplex ............. 13 1.6.1 Basic Sysplex ................................. 13 1.6.2 Parallel Sysplex ................................ 14 1.7 How Do I Quickly Get to Parallel Sysplex? ................... 14 1.8 Function Support Table for Pre-G5 9672 CPCs ................ 15 2.0 High-Level Design Concepts for Parallel Sysplex ............... 17 2.1.1 Important Rules of Thumb Information .................. 18 2.2 Deciding If Parallel Sysplex Is Right for You .................. 18 2.2.1 S/390 Partners in Development Software ................. 23 2.3 Parallel Sysplex High-Level Design ....................... 26 2.3.1 How Many Parallel Sysplexes Do I Need? ................ 26 2.3.2 System Symmetry When Configuring a Parallel Sysplex ........ 38 2.3.3 What Different 'Plexes Are There? ..................... 39 2.3.4 How Do 'Plexes Relate to Each Other? .................. 42 2.3.5 'Plex Summary ................................ 68 2.4 CF Architecture ................................... 71 2.4.1 XES Providing Software Access to the CF ................ 73 2.5 Data Integrity and Buffer Pool Consistency Considerations ......... 78 2.5.1 Data Integrity before Parallel Sysplex ................... 78 2.5.2 Data Integrity in Parallel Sysplex ...................... 79 2.5.3 Locking in Parallel Sysplex ......................... 82 2.6 Dynamic Workload Balancing in Parallel Sysplex .............. 83 2.6.1 Dynamic Workload Balancing Exploiters ................. 84 Copyright IBM Corp. 2000 iii 3.0 Continuous Availability in Parallel Sysplex ................... 89 3.1 Why Availability Is Important ........................... 91 3.1.1 Parallel Sysplex Is Designed to Allow Management of Redundancy . 91 3.1.2 Planned Outages ............................... 93 3.1.3 Unplanned Outages .............................. 95 3.1.4 Scope of an Outage .............................. 95 3.2 Software Considerations for Availability .................... 97 3.2.1 Data Set Redundancy ............................. 97 3.2.2 Couple Data Set Considerations ...................... 98 3.2.3 JES3 and Continuous Availability ...................... 98 3.2.4 Subsystem Considerations ........................ 101 3.3 Network Considerations for Availability ................... 104 3.3.1 VTAM Generic Resources Function ................... 104 3.3.2 Persistent Sessions ............................. 104 3.3.3 Multi-Node Persistent Sessions ...................... 105 3.3.4 High Performance Routing ......................... 107 3.3.5 VTAM Systems Management ....................... 107 3.3.6 TCP/IP Virtual IP Addressing ....................... 108 3.3.7 Dynamic VIPA Takeover .......................... 110 3.3.8 Sysplex Distributor ............................. 110 3.4 Hardware Considerations for Availability ................... 111 3.4.1 Number of CPCs in Parallel Sysplex ................... 111 3.4.2 Redundant Power .............................. 111 3.4.3 Isolate the CF ................................ 112 3.4.4 Additional CF Links ............................. 115 3.4.5 I/O Configuration Redundancy ...................... 115 3.4.6 Sysplex Timer Redundancy ........................ 116 3.4.7 RAS Features on IBM CPCs ........................ 116 3.5 Limitations to Continuous Availability ..................... 116 3.6 Recovery Considerations for Availability ................... 117 3.6.1 Sysplex Failure Management (SFM) ................... 117 3.6.2 Automatic Restart Management (ARM) ................. 123 3.7 Disaster Recovery Considerations in Parallel Sysplex ........... 126 3.7.1 Multi-Site Sysplexes ............................ 127 3.7.2 Disaster Recovery Data .......................... 130 3.7.3 CICS Disaster Recovery Considerations ................ 133 3.7.4 DB2 Disaster Recovery Considerations ................. 133 3.7.5 IMS Disaster Recovery Considerations ................. 134 3.7.6 Geographically Dispersed Parallel Sysplex Offering ......... 135 3.7.7 More Information on GDPS ........................ 138 3.7.8 Recommended Sources of Disaster Recovery Information ..... 139 4.0 Workloads in Parallel Sysplex ......................... 141 4.1 e-business and Parallel Sysplex ........................ 143 4.1.1 Web Server .................................. 144 4.1.2 HTML Serving ................................ 147 4.1.3 3270 Emulation ................................ 147 4.1.4 CICS ...................................... 148 4.1.5 DB2 ...................................... 156 4.1.6 IMS ...................................... 160 4.2 Transaction Management in Parallel Sysplex ................ 169 4.2.1 Dynamic Transaction Routing ....................... 169 4.2.2 CICS Transactions in a Parallel Sysplex ................ 169 4.2.3 CICSPlex Systems Manager (CICSPlex SM) .............. 185 4.2.4 CICS Transaction Affinity Utility ...................... 187 iv Parallel Sysplex Configuration, Volume 1: Overview 4.2.5 IMS Transaction Manager in Parallel Sysplex ............. 187 4.3 Database Management in Parallel Sysplex ................. 194 4.3.1 DB2 Data Sharing Considerations .................... 194 4.3.2 IMS DB Data Sharing ............................ 203 4.3.3 CICS/VSAM Record Level Sharing Considerations .......... 207 4.3.4 S/390 Partners in Development Databases ............... 213 4.4 Batch Workload Considerations ........................ 213 4.4.1 JES2 Considerations in Parallel Sysplex ................ 213 4.4.2 JES3 Considerations in Parallel Sysplex ................ 214 4.4.3 Can I Have JES2 and JES3 in the Same Sysplex ........... 215 4.4.4 Batch Workload Balancing and Parallel Sysplex ........... 215 4.4.5 IBM BatchPipes for OS/390 ........................ 215 4.5 Network Workload Balancing Capabilities .................. 219 4.5.1 VTAM Generic Resources Function ................... 219 4.5.2 TCP Workload Balancing .......................... 225 4.6 APPC/MVS and Parallel Sysplex ........................ 226 4.7 TSO/E and Parallel Sysplex ........................... 227 4.7.1 MAS Considerations ............................ 227 4.7.2 Query Management Facility Workload Considerations ........ 228 4.8 Test Considerations in Parallel Sysplex ................... 228 4.8.1 Testing Implications in Parallel Sysplex ................