Data Sharing in a Nutshell

1 For z/OS: data Sharing in a NutshellPaolo BruniMark AndersKyengDong ParkMark RaderJudy Ruby-BrownGet a quick start with your DB2 for z/OS data Sharing installationUnderstand alternatives and prioritiesFind support and referencesFront coverDB2 for z/OS: data Sharing in a NutshellInternational Technical Support OrganizationSG24-7322-00 Copyright International Business Machines Corporation 2006. All rights to Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADPS chedule Contract with IBM Edition (October 2006)This edition applies to IBM DB2 Version for z/OS (program number 5635-DB2) and earlier currently supported releases. Note: Before using this information and the product it supports, read the information in Notices on page vii. Copyright IBM Corp. 2006. All rights .. viiTrademarks .. viiiPreface .. ixOur assumptions .. ixThe team that wrote this redbook .. xBecome a published author .. xiiComments welcome .. xiiiChapter 1.

2 Introduction.. Why should you implement DB2 data Sharing ? .. Overview of Parallel Sysplex and DB2 data Sharing .. Business value of data Sharing .. Improved data availability .. Extended processing capacity .. Configuration flexibility .. Higher transaction rates .. Application interface unchanged .. Roadmap to implementing data Sharing .. 11 Chapter 2. data Sharing architecture.. Parallel database architecture alternatives .. data Sharing design for scalability.. Global locking and the lock structure .. Managing changed data and group buffer pools.. data Sharing design for continuous availability .. Configuration flexibility and systems management .. Application considerations in data Sharing .. Portability .. Commit and lock avoidance .. Concurrency .. 37 Chapter 3. The coupling facility.. Structure sizing .. Group buffer pools .. Sizing the lock structure .. Sizing the SCA structure .. Auto Alter.

3 Implementing Auto Alter .. 50iv data Sharing in a Duplexing .. Group buffer pools (GBP) or user-managed pools .. System-managed duplexing .. CF configuration alternatives.. ICF-only: Double failure for the lock and SCA structures .. System-managed duplexing for DB2 lock and other structures .. External CF, such as z890 or z9 BC .. CFRM policy .. Best practices for the coupling facility .. 63 Chapter 4. Implementing data Sharing .. Naming conventions .. Group name .. Group attachment name .. Subsystem identifier (SSID) .. Log data set names.. Bootstrap data set (BSDS) .. Distributed data Facility (DDF) related parameters .. Catalog alias .. Temporary work file database .. Some more naming recommendations .. Examples of naming conventions .. Best practices for naming conventions .. Logging .. Active log data sets .. Archive log .. Best practices for DB2 logging .. DSNZPARMs .. data Sharing system parameters.

4 Some other important DSNZPARMs.. IRLM parameters .. Information stored in the BSDS.. Renaming an existing non- data Sharing member .. IPL required for these tasks .. Enable data Sharing tasks .. Enabling the data Sharing group .. Additional tasks .. Adding the second member .. Removing a member .. 88 Chapter 5. Dynamic workload balancing .. Objectives of workload balancing .. Workload Manager .. 92 Contents Dynamic virtual IP addressing (DVIPA).. Sysplex Distributor .. Distributed data facility (DDF) .. Stored procedures .. Batch work.. WebSphere .. CICSPlex Systems Manager (CP/SM) .. IMS Transaction Manager (IMS TM) .. Dynamic workload balancing best practices .. 103 Chapter 6. Operations.. Recovery of DB2 objects .. Log record sequence number (LSRN) .. Group buffer pool recovery pending (GRECP) .. Logical page list (LPL).. Recommendations for GRECP/LPL recovery .. Best practices for GRECP/LPL recovery.

5 Component failure .. DB2 subsystem failure .. z/OS system failure .. CF failure.. Sysplex failure management (SFM) policy .. Automatic restart manager (ARM).. Restart Light .. Best practices for failures .. Commands .. Basics .. CF and structure related commands .. IRLM commands .. DB2 commands.. Multi-system DB2 diagnostic dumps .. Disaster recovery .. Rolling maintenance .. Service recommendations.. Best practices for maintenance .. 120 Chapter 7. Advanced topics.. CLOSE YES and CLOSE NO table spaces .. Best practice .. Performance .. Eliminating false contention.. How many CF engines are necessary? .. Lock avoidance: CLSN versus GCLSN .. 128vi data Sharing in a The problem of runaway threads.. Usermod for routing to multiple DB2s on a z/OS image .. Multiple DB2 members in one z/OS image .. Determining the number of threads .. REXX tools package .. Statistics Spreadsheet support.

6 133 Chapter 8. Best practices.. Table of best practice recommendations .. 136 Related publications .. 139 IBM Redbooks .. 139 Other publications .. 139 Online resources .. 140 How to get IBM Redbooks .. 142 Help from IBM .. 142 Index .. 143 Copyright IBM Corp. 2006. All rights information was developed for products and services offered in the IBM may not offer the products, services, or features discussed in this document in other countries. Consult your local IBM representative for information on the products and services currently available in your area. Any reference to an IBM product, program, or service is not intended to state or imply that only that IBM product, program, or service may be used. Any functionally equivalent product, program, or service that does not infringe any IBM intellectual property right may be used instead. However, it is the user's responsibility to evaluate and verify the operation of any non-IBM product, program, or service. IBM may have patents or pending patent applications covering subject matter described in this document.

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9 All of these names are fictitious and any similarity to the names and addresses used by an actual business enterprise is entirely coincidental. COPYRIGHT LICENSE:This information contains sample application programs in source language, which illustrate programming techniques on various operating platforms. You may copy, modify, and distribute these sample programs in any form without payment to IBM, for the purposes of developing, using, marketing or distributing application programs conforming to the application programming interface for the operating platform for which the sample programs are written. These examples have not been thoroughly tested under all conditions. IBM, therefore, cannot guarantee or imply reliability, serviceability, or function of these programs. viii DB2 for z/OS: data Sharing in a NutshellTrademarksThe following terms are trademarks of the International Business Machines Corporation in the United States, other countries, or both: Eserver Eserver Redbooks (logo) z/OS zSeries z9 CICS CICSPlex DB2 Connect DB2 DFSMSdfp DRDA ESCON FICON IBM IMS MQSeries MVS OMEGAMON OS/390 Parallel Sysplex Redbooks RACF RMF Sysplex Timer System z System z9 Tivoli VTAM WebSphere System z is the brand name to indicate both the zSeries and System z9 families of following terms are trademarks of other companies:Java, JDBC, and all Java-based trademarks are trademarks of Sun Microsystems, Inc.

10 In the United States, other countries, or company, product, or service names may be trademarks or service marks of others. Copyright IBM Corp. 2006. All rights for z/OS takes advantage of data Sharing technology in a z Parallel Sysplex to provide applications with full concurrent read and write access to shared DB2 data . data Sharing allows users on multiple DB2 subsystems, members of a data Sharing group, to share a single copy of the DB2 catalog, directory, and user data Sharing provides improvements to availability and capacity without impacting existing road to data Sharing might seem arduous to a novice user, but once you have started to learn terminology and gain basic understanding, things will become much IBM Redbook is meant to facilitate your journey towards data Sharing by providing a cookbook approach to the main tasks in enabling data Sharing and workload balancing. It does not have all the answers, because it is a brief summary of a large field of knowledge, but it contains the key elements and it points you in the right direction to get more details.