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IBM IMS/ESA V6 Parallel Sysplex Migration Planning Guide for IMS TM DBCTL

1. 157 Chapter 16 IMS Connections Security and User Exits 159 16 1 IMS Connections 159 16 2 S6Curity Lx Mire spear gen 160 16 21 HAGF Sec rity us 160 16 3 IMS SMU Security 161 16 4 Database Data Set Dispositions 161 16 52 T Su menn ESSO UE RED RE S 162 16 5 1 IMS System Exits 162 16 5 2 IMS Database Manager Exits 163 16 5 3 IMS Transaction Manager Exits 163 16 5 4 Common Queue Server Exit Routines 164 Chapter 17 IMS and User JCL 167 1751 IMS Procedures xao Ve le Ow Pe douar de xxt 167 17 1 1 Started Procedures 167 17 1 2 Executed Procedures 170 17 2 IMS JODS i assem badd hed de Bode Rom huis 170 17 3 DBRC Skeletal JCL 172 17 4 Other Backup and Recovery JCL 173 17 5 Other Application JOL 173 17 6 BMP JGL 4 sche teresa doe iS a 173 17 6 1 Using the Function Delivered by PQ21039 173 17 6 2 The IMSGROUP Function 174 17 6 3 Handling IMSID Without PQ
2. 215 B 2 Data Sets That Must Be Shared 216 Data Sets That Are Probably Unique 216 B 4 Data Sets That Are Probably Shared 216 Appendix C Sample USERVAR Exit for Network Balancing 219 Appendix D Parallel Sysplex Publications 231 Appendix E Migration Plan Task List 233 Planning 252 225 Ee ese Dh Pee RIEN 234 E2 Preparation Phase 235 Implementation Phase 237 E 3 1 Data Sharing Environment Implementation 237 E 3 2 Generic Resources Environment Implementation 237 E 3 3 Shared Queues Environment Implementation 238 E 3 4 Implementation of Second System Clone 238 Appendix Special Notices 239 Appendix Related Publications 241 G 1 International Technical Support Organization Publications 241 G 2 Redbooks on CD ROMs 241 G 3 Ofh r Publications uuu na Bbw eo arabe Beis sats 241 How to Get ITSO Redbooks 243 IBM Redbook Fax Order Form 244 Glossary x Bo AE acide oe ergot Moe e Pd 245 List of Abbreviations 249 Indexi i
3. 125 12 5 Structure Recovery Data Sets 126 12 6 Procedure 126 12 7 BPE Configuration PROCLIB Member 126 12 8 CQS Initialization Parameters PROCLIB Member CQSIPxxx 126 12 9 CQS Local Structure Definition PROCLIB Member CQSSLxxx 126 12 10 CQS Global Structure Definition PROCLIB Member CQSSGxxx 126 12 11 Security for CQS Structures 127 12 12 ARM Policy Updates 127 12 13 IMS Shared Queues PROCLIB Member DFSSQxxx 127 12 14 and Shared Queues Traces 127 12 15 IMS Proc dure EE Sea ar 127 12 16 IMS Procedures for Shared Queues 127 Part 5 MVS Parallel Sysplex Conderations 129 Chapter 13 VTAM Generic Resources Enablement 131 13 1 VTAM Requirements 131 13 2 IMS Requirements 131 13 3 APPC IMS Requirements 131 Chapter 14 Automatic Restart Manager ARM 133 14 1 Exceptions to Automated Restarts of IMS 133 14 2 Restart Conditions 134 14 3 Restart Groups 134 14 4 Other ARM Capabilities 135 14 5 ARM with IREM
4. Although not an official IBM term this publication uses the term MSplex to represent a collection of IMS TM subsystems that are related either by sharing common databases and or message queues or by providing common services to the end user community In effect the end user should view the IMSplex as a single entity a provider of IMS service IMSplex is generally defined as those IMSs within the same Parallel Sysplex environment which are related in some manner to provide IMS services to end users in session with one or more of these IMSs The IMSs within the IMSplex are related by being members of the same data sharing and or shared queues groups or by sharing workload using MSC or ISC While an IMSplex should have the appearance of a single provider of service to the end user community the IMS ESA Transaction Manager implementation of IMSplex using traditional queuing is really just a collection of independent IMS systems that happen to be sharing databases and or are interconnected through MSC or ISC links Each IMS system has its own set of master terminals its own set of message queues its own set of message regions and so forth In other words each of the IMS TM systems is an entity unto itself The only things that tie the IMS TM systems together are data sharing they share a common set of databases and or MSC ISC links they can route work from one system to another under application user exit or system definition c
5. 91 10 5 3 Example Migration of Two MSC Connected Systems 95 10 5 4 Example MSC Link from a Shared Queues Group Member to a Remote IMS oues mes Go ee BE oe ood ed ti o Re uela 97 10 5 5 Example MSC Link Between Members of Two Shared Queues Groups x Eudora rus pete ha dete oed oq Nd Y redu a 99 10 5 6 Example Multiple MSC Links between Members of Two Shared Queues Groups uox Rue Ee mue ue 99 10 5 7 Example Backup MSC Link Configuration 100 10 6 Serial Transactions 102 10 6 1 Serial Transactions With Traditional Queuing 102 10 6 2 Serial Transactions With Shared Queues 102 10 7 Undefined Destinations 103 10 7 1 Destination Determination 104 10 7 2 Back End Processing of Input Transactions 104 10 7 3 Comments and Recommendations 104 10 8 Online Change 2 23 3d aS Sout ee eae ox S rari 105 10 9 SPOOL Terminals 105 Part 4 Data Sharing and Shared Queues Considerations 107 Chapter 11 Data Sharing Enablement 109 11 1 IMS System Definition 109 14 2 REM ET e Y e Um ORE 110 11 2 1 Subsystem Names 110 11 2 8 as Lock Manage
6. Existing IMS runs applications which ALLOCATE explicit conversations with APPC applications MQSeries ESS and BMP Existing IMS receives MQSeries input using Calls and the Trigger Monitor BMP MQSeries OTMA Existing IMS receives MQSeries input through MQSeries IMS Bridge using OTMA Copyright IBM Corp 1999 159 16 2 Security Table 6 Page 2 of 2 Summary of IMS Connectors CONNECTOR CONNECTION DESCRIPTION TYPE TYPE Web Server OTMA Existing IMS receives transactions from the Web through the IMS TCP IP OTMA Connection ITOC Web Server Existing IMS receives transactions from the Web through an APPC connection JAVA OTMA Existing IMS receives transactions from a JAVA application through the IMS TCP IP OTMA Connection ITOC TCP IP BMP Existing IMS uses a BMP to provide a sockets Sockets interface TCP IP OTMA Existing IMS uses ITOC for sockets connections DCE RPC ISC Existing IMS receives RPC requests through DCE Application Server s ISC interface DCE RPC APPC Existing IMS receives RPC requests through DCE Application Server s APPC interface DCE RPC OTMA Existing IMS receives RPC requests through DCE Application Server s OTMA interface ODBA DRA Provides MVS batch application program access to IMS TM or DBCTL databases It is the responsibility of the installation to provide the security environment for the couple data sets RACF or an equivalent secur
7. IMS ESA V6 Parallel Sysplex Migration Planning Guide for IMS TM and DBCTL Bob Gendry Bill Keene Rich Lewis Bill Stillwell Scott Chen International Technical Support Organization http www redbooks ibm com SG24 5461 00 x SG24 5461 00 International Technical Support Organization IMS ESA V6 Parallel Sysplex Migration Planning Guide for IMS TM and DBCTL June 1999 Take Note Before using this information and the product it supports be sure to read the general information in Appendix F Special Notices on page 239 First Edition June 1999 This edition applies to Version 6 Release Number 1 of IMS ESA Program Number 5655 158 for use with the MVS ESA or OS 390 operating system Comments may be addressed to IBM Corporation International Technical Support Organization Dept Building 80 E2 650 Harry Road San Jose California 95120 6099 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 1999 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 aoi doe Sane ak BAS Soe de He ah ele aie xi Tabl
8. or DBCTL Abends 200 20 5 IREM Abends oes Raw X ac rA s 200 20 6 MVS Failures 4 224 ho 24d LO eMe ele iru kb Eu pre hs 200 20 7 Lock Structure Failures 201 20 8 OSAM and VSAM Structure Failures 202 20 9 DEDB VSO Structure Failures 202 20 9 1 Procedure for Failure of One of Two Structures 203 20 9 2 Procedure for Failure of Only Structure or Both Structures 2 203 20 10 CF Connection Failures 203 20 11 CF Connection Failure to Lock Structure 203 20 12 CF Connection Failure to an OSAM or VSAM Structure 204 20 13 CF Connection Failure to DEDB VSO Structure 204 20 13 1 Procedure with Connectivity to a Second Structure 205 20 13 2 Procedure without Connectivity to a Second Structure 205 20 14 Disaster Recovery 205 20 14 1 Image Copy Only Disaster Recovery 205 20 14 2 Time Stamp Recovery Disaster Recovery 206 20 14 3 Latest Archived Log Disaster Recovery 206 20 14 4 Real Time Electronic Log Vaulting Disaster Recovery 207 IMS Parallel Sysplex Migration Planning Guide Appendix A Naming Convention Suggestions 209 Appendix B IMS System Data Sets 215 B 1 Data Sets That Must Be Unique
9. E mail Orders Send orders by e mail including information from the redbook fax order form to In United States e mail address usib6fpl ibmmail com Outside North America Contact information is in the How to Order section at this site http www elink ibmlink ibm com pbl pbl Telephone Orders United States toll free 1 800 879 2755 Canada toll free 1 800 IBM 4YOU Outside North America Country coordinator phone number is in the How to Order section at this site http www elink ibmlink ibm com pbl pbl Fax Orders United States toll free 1 800 445 9269 Canada 1 403 267 4455 Outside North America Fax phone number is in the How to Order section at this site http www elink ibmlink ibm com pbl pbl This information was current at the time of publication but is continually subject to change The latest information may be found at the redbooks Web site IBM Intranet for Employees IBM employees may register for information on workshops residencies and redbooks by accessing the IBM Intranet Web site at http w3 itso ibm com and clicking the ITSO Mailing List button Look in the Materials repository for workshops presentations papers and Web pages developed and written by the ITSO technical professionals click the Additional Materials button Employees may access MyNews at http w3 ibm com for redbook residency and workshop announcements Copyright IBM Corp 1999 243 IBM Redbook Fax Order F
10. 250 IMS Parallel Sysplex Migration Planning Guide TM TSO UOW VSAM VTAM WLM XCF XRF Transaction manager Time sharing option Unit of work Virtual sequential access method Virtual storage option Virtual telecommunications access method Work load manager Extended control facility Extended recovery facility Index Special Characters CHE command 57 DBD command 17 186 DBR command 17 179 186 DISPLAY command 187 MODIFY command 184 MSASSIGN command 75 OPNDST command 76 QUIESCE command 57 START command 16 34 186 STOP command 16 17 186 Numerics 0001 136 0010 136 0014 136 0018 136 0020 136 A abbreviations 249 ACBLIB 38 184 acronyms 249 APPC 58 131 159 GRAFFIN parameter 131 ISTEXCGR 131 Resource Resolution Exit 131 APPC IMS 24 58 72 131 APPC MVS 24 58 Application 14 41 50 81 88 Application program 14 32 62 Cloned applications 42 Partitioned 42 Workload balancing 53 81 Application databases 41 Partitioned 41 ARM 25 75 126 133 136 200 201 CQS 136 FDBR 137 Restart groups 134 bibliography 241 BMP 7 16 23 25 62 121 133 171 174 201 ALTID parameter 175 BMP backout 25 BMP restart 25 Copyright IBM Corp 1999 CF connection 203 204 CFIRLM 113 CFNAMES 113 Change accumulation 198 CICS 23 27 42 55 68 134 201 Transactions routing 42 Command 16 DBD 17 199 205 206 17 198 199 205 206 DEQ 61 DIS 61 MSA
11. To what systems is the existing IMS connected This should include other IMSs DB2s CICSs and any other intelligent systems or devices that might be sensitive to the identity of the IMS system to which they are connected What are the online and batch schedules What are the hours of availability for online access and what is the batch window if there is one Are there any batch or online dependencies Are there sequences of processes that must be maintained in the target environment For example transactions defined as SERIAL implying a FIFO processing sequence should be identified Are any user exits sensitive to the identity of the IMS system on which they execute Look particularly at transaction manager exits and system exits as there will be multiple transaction managers with different IDs connected perhaps to different subsystems for instance different CICSs or different DB2s and with only part of the original network Do any user written programs process the IMS logs The logs will be quite different with each log containing only part of the information that was on the original single image log What are the business critical applications If one component of the target environment fails for instance one of two IMS systems and can t be immediately restarted it might be necessary to quiesce relatively unimportant work on the surviving system in order to shift the entire critical wo
12. only one system For example they might want all batch work to run on a large processor If they have processors with different capacities they might want the fastest processor to handle all of their batch work These installations would route all BMP jobs to the MVS system on the fastest processor They have two choices for specifying the IMSID First they could use the default specified in a RESLIB All BMPs would use the same RESLIB This RESLIB would have the appropriate IMSID Second they could specify the IMSID in the execution parameters All BMPs would use the same IMSID A BMP is run on only two IMS systems The BMP parameters include ALTID ALTID specifies an alternate IMSID A BMP will attempt to use the IMS system specified on its IMSID parameter If an IMS system with this IMSID is not present on the MVS system the BMP will attempt to use the IMS system specified by the ALTID This allows a BMP to specify a first and second choice for IMS systems There is no default for the ALTID It must be specified in the BMP s JCL In this case the BMPs would specify both the IMSID and the ALTID execution parameters A BMP can be run on more than two IMS systems If there are more than two IMS systems on which a BMP be run its IMSID might have to be modified with each execution The modification might be made in four ways First the IMSID JCL parameter can be changed Second the library containing the default IMSID in its DFS
13. 68 VTAM USERVAR processing was invented for IMS and CICS XRF eXtended Recovery Facility but has uses other than for XRF One can think of USERVAR processing as indirect addressing for APPLID names Rather than specifying an APPLID in a USSTAB or logon request one can specify the name of a USERVAR The contents of the USERVAR are then used by VTAM to obtain the actual APPLID name in effect VTAM uses the contents of the USERVAR to transform the USERVAR name to an APPLID name The key to using USERVAR processing to balance logon requests is to control how the USERVAR transformation process occurs If one can ensure that 50 percent of the logon USERVAR transformation operations resulted in an APPLID of IMS1 and that 50 percent of the transformations resulted in an APPLID of IMS2 the objective of a 50 50 split of logon requests will be met There are two ways to make this happen The contents of a USERVAR can be changed through a VTAM command Therefore one can provide automation to periodically issue VTAM commands to change the contents of the USERVAR such that it contained IMS1 50 percent of the time and IMS2 50 percent of the time The advantages of this technique are that it does not require any VTAM exits and the automation product or tool can look at the current logon distribution and adjust its algorithm accordingly The disadvantages of this technique are that there is no repeatability for a given LU to be logged on to the same IM
14. These could cause increased lock contention The IRLM subsystem name must be known to the operating system therefore it must be included in the IEFSSNxx member or added by SETSSI command before this step is taken 6 Define the CF structures in the XCF Administrative Data Utility Defining the structures will have no effect before they are specified to IMS or IRLM 7 Include a CFNAMES statement in DFSVSMxx IMS Parallel Sysplex Migration Planning Guide 10 11 12 CFNAMES statement with CFOSAM and CFVSAM specifications will cause IMS to build the buffer invalidation cache structures Read and register will occur Since data sharing is not yet being done no buffer invalidations will occur however the overhead of read and register operations will be added to the system If IMS ESA V6 1 is being used include the dirratio and elemratio values in the CFOSAM specification A value for CFIRLM must be specified Since the IRLM is still SCOPE LOCAL the lock structure will not be built and no additional locking overhead will be added Include DEDB statements in DFSVSMxx for VSO areas DEDB statements define VSO buffer pools These are required for VSO areas which are shared The buffer pools are built at IMS initialization They will not be used unless DEDBs with VSO areas are registered at SHARELVL 2 or SHARELVL 3 Register databases at SHARELVL 2 This will cause block locks to be requested Locks for
15. 136 14 5 1 Restarting after Abends 136 14 5 2 Restarting after System Failures 136 14 6 ARM with COS 136 14 7 ARM with FDBR 137 14 8 Information for ARM Policies 137 Chapter 15 Coupling Facility 139 15 1 Coupling Facility Planning Guidelines 139 15 1 1 Structure Placement Rules 139 15 1 2 Initial Structure Placement 140 vi IMS Parallel Sysplex Migration Planning Guide 15 1 3 Structure Sizing Lai neu 141 15 1 4 IMS Database Manager 141 LOTS IREM Duce IS T 6 borse s face ek 146 15 1 6 Shared Queues 148 15 1 7 Summary of Structure Characteristics 150 15 2 Changing CF Structure Sizes 151 15 2 1 Connection and Structure Persistence 151 15 2 2 IMS Buffer Invalidation Structure Changes 151 15 2 3 DEDB VSO Cache Structure Changes 152 15 2 4 Lock Structure Changes 152 15 2 5 Automatic Rebuilds 153 15 2 6 Shared Queues Structure Changes 154 15 2 7 Alter and Rebuild for Shared Queues Structures 154 Part 6 Operation Considerations
16. B INVOKE3 LOOP 01550000 INVOKE4 DS OH CORRECT DISTRIBUTION ENTRY FOUND 01560000 MVC TRANVAL DISTAPPL MOVE APPLID TO PARM LIST 01570000 01 FLAGS TRANSLAT SET TRANSLATE FLAG ON 01580000 INVOKRET DS OH RETURN 01590000 RETURN 14 12 RC 0 01600000 DROP R2 DROP PARAMETER BASE 01610000 DROP R3 DROP USERVAR PARMS BASE 01620000 DROP R4 DROP USERVAR TABLE ENTRY BASE 01630000 DROP R5 DROP DISTRIBUTION TABLE ENTRY BASE 01640000 TITLE SAMPLE USERVAR EXIT TO DISTRIBUTE LOGON REQUESTS TO MULX01650000 TIPLE IMS SYSTEMS EXIT ACT REPL 01660000 X Ck ok Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck OK RK RK RK 01670000 01680000 OBTAIN STORAGE FOR USERVAR LIST DISTRIBUTION LIST AND USER DATA 01690000 WORKING STORAGE 01700000 STORAGE REQUEST FAILED THEN 01710000 ISSUE ERROR WTO AND RETURN 01720000 BUILD USERVAR AND DISTRIBUTION LISTS IN OBTAINED STORAGE 01730000 USER DATA PROVIDED THEN 01740000 VALIDATE USERVAR NAME AND DISTRIBUTION PARAMETERS 01750000 IF PARAMETER ERROR THEN 01760000 ISSUE ERROR AND RETURN 01770000 ELSE 01780000 OVER RIDE SPECIFIED USERVAR PARAMETER DATA 01790000 RETURN 01800000 01810000 KR ok Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck Ck RK Ck Ck OX RK K 1820000 SPACE 1 01830000 ACT DS OH 01840000 REPL DS OH 01850000 LR R7 R1 SAVE PARAMETER ADDR 01860000 L R2 WRKSPCLN GET SIZE OF REQUIRED ST
17. amp MBR IMS IMSP PD11 JOBS would have to have a member named MSGP01 which could be tailored specifically to PD11 MSGPO1 JOB EXEC MPRPO1 IMSID PDI1 JOB tailored for 11 MPRPO1 PROC lt PROC common to all IMSs In this way a common IMSRDR PROC can be used to execute jobs from IMS JOBS libraries that are unique and tailored to a specific IMS regardless of which MVS system it is running on With IMS V6 the START REGION command has been enhanced and gives us the ability to share IMS JOBS library members among different IMS subsystems This eliminates the need for a unique IMS JOBS library for each IMS in the Parallel Sysplex This is made possible by the following Include dependent region execution procedures in each control region s PROCLIB DD concatenation conceivably this could be the IMS JOBS Chapter 5 System Environment Consideration 35 library The execution procedure found in the PROCLIB DD concatenation is used when a START REGION command is entered that includes one or both of the new keyword options with the entered command and are described in the bullets that follow When one or both of these new keyword options is used the IMSID keyword option in the procedure is overridden with the IMSID of the IMS subsystem on which the START REGION command was entered Overlay the jobname of the IMS PROCLIB procedure member with the jobname specified with the entry of the START REGION
18. 02400000 02410000 02420000 02430000 02440000 02450000 02460000 02470000 02480000 02490000 02500000 02510000 02520000 02530000 02540000 02550000 02560000 02570000 02580000 02590000 02600000 02610000 02620000 02630000 02640000 02650000 02660000 02670000 02680000 02690000 02700000 02710000 02720000 02730000 02740000 02750000 02760000 02770000 02780000 02790000 02800000 02810000 Appendix C Sample USERVAR Exit for Network Balancing 223 LA R7 DISTMAX SET LOOP COUNTER 02820000 LA R6 WSDIST POINT FOR FIRST WS DIST ENTRY 02830000 ACT6 DS OH INIT WS LOOP 02840000 MVC O L WSDIST R6 F 1 SET WS DIST ENTRY TO 1 02850000 LA R6 L WSDIST R6 POINT TO NEXT WS DIST ENTRY 02860000 BCT R7 ACT6 LOOP DISTMAX TIMES 02870000 SAVE USERVAR NAME FROM USER DATA AND CHECK DIST SYNTAX 02880000 MVC WSUSRVAR O R4 MOVE USERVAR NAME TO WS 02890000 LA R6 8 R4 GET ADDR OF FIRST OVER RIDE 02900000 LA R7 WSDIST GET ADDR OF FIRST WS DIST ENTRY 02910000 ACT7 DS OH SYNTAX CHECKING LOOP 02920000 CLI 0 R6 C IS 1ST CHAR A COMMA 02930000 BNE PARMERR NO ERROR 02940000 1 3 R6 TRTABLE ARE NEXT 3 CHARS NUMERIC 02950000 BNZ PARMERR NO ERROR 02960000 PACK WSDOUBLE 1 3 R6 PACK DIST OVER RIDE 02970000 CVB R2 WSDOUBLE CONVERT DIST OVER RIDE TO BINARY 02980000 ST R2 0 R7 STORE IN WS DIST ENTRY 02990000 LA R6 4 R6 GET ADDR OF NEXT OVER RIDE 03000000 LA R7 L WSDIST R7 GET ADDR OF NEXT WS DIST ENTRY 0301
19. 191 19 3 FDBR Failures If FDBR fails while it is tracking IMS it can be restarted and resume tracking The restart can be done by the operator or by the Automatic Restart Manager ARM ARM support for FDBR is explained below If FDBR fails while it is in database recovery phase it cannot be restarted FDBR restart requires that its associated IMS be active If FDBR fails in its database recovery phase the IMS system should be emergency restarted This will complete the database recovery processes 19 4 Restarting IMS after FDBR Completion IMS must be restarted after FDBR completes its recovery processes Restart is required to resolve in doubt threads with CICS and DB2 recover message queues change the DBRC subsystem record from failed to normal release DBRC authorizations and recover MSDBs This recovery should be done as soon as possible but cannot be done before FDBR completes Of course an installation will also want the restarted IMS to process new work When FDBR completes its recovery processing it issues the following message DFS4168I FDR FOR imsid DATABASE RECOVERY COMPLETED Automation can use this message to indicate that FDBR s recovery is complete and that the associated IMS should be emergency restarted 19 5 DBRC Authorizations with FDBR FDBR does not change the DBRC subsystem record from failed to normal It also does not release database authorizations When FDBR completes it has released locks held by
20. Affinities are deleted during normal or abnormal session termination unless one or more of the following is true The terminal retains significant status Significant status is discussed beginning with the paragraph following this list Session termination is for a SLUTYPEP or FINANCE terminal Session termination is for the last ISC parallel session with a given node and not all parallel sessions including this last session to that node have been quiesced Significant status is set for a terminal if it is in response or conversational mode of execution or when the terminal is in some preset state or mode of operation such as MFSTEST test preset or exclusive Significant status is always maintained for a static terminal whether its session is active or not significant status is maintained for a dynamic ETO terminal when the user is signed on and is reset when the user is signed off normally or abnormally The type of system failure IMS or MVS also determines whether affinities are released when the failure occurs When the failure is an IMS failure IMS s ESTAE processing releases all affinities unless the terminal has significant status is a SLUTYPEP or FINANCE device or is associated with an ISC connection where all parallel sessions have not been quiesced IMS Parallel Sysplex Migration Planning Guide If sessions are lost because of an MVS failure IMS s ESTAE routine does not get control and affinities are not del
21. RECOVERY RECOVJCL Database Recovery can be run on any MVS system in the Sysplex RECEIVE ICRCVJCL RSR image copy receive processing occurs at the remote site not at the operational site This is independent of data sharing ONLINE IMAGE COPY OLICJCL Online Image Copy OLIC can be run on any IMS system however the other IMS systems cannot have update intent while OLIC is being run for a database Since OLIC is run as a BMP it must specify or default to the IMSID of the IMS system running on the MVS where OLIC is executed GENJCL OLIC is not required for generating OLIC JCL unless the database data set has REUSE specified for it in the RECONs LOG CLOSE LOGCLJCL IMS Parallel Sysplex Migration Planning Guide The Log Recovery utility be on MVS system in the Sysplex The IMS supplied member includes the SSID parameter to identify the IMS system whose log is being closed USER This is installation dependent Members used by GENJCL USER should be reviewed for any IMS system dependencies 17 4 Other Backup and Recovery JCL If DBRC GENJCL is not used to generate backup and recovery JCL this JCL must be identified and reviewed In general database backups and recoveries can be run on any MVS system however an installation might want to direct these jobs to a specific MVS system for performance or operational reasons Online Image Copy must run on the MVS system where its IMS control region is e
22. Specify ISOLATETIME in the Sysplex Failure Management SFM policy This causes system isolation to be invoked for a failed MVS system A specification of PROMPT instead of ISOLATETIME requires operator actions when XCF status monitoring recognizes the time out of an MVS system Use name that associates FDBR with the IMS it tracks Commands for FDBR are issued by using an MVS modify command and specifying the FDBR procname This procname should be easily associated with the IMS system which the FDBR system tracks For example the FDBR procname could include the IMSID Similarly the XCF group name used for FDBR should also include the IMSID The default group name is FDR followed by the IMSID It is reasonable to make the FDBR procname the same as the XCF group name Chapter 19 Fast Database Recovery FDBR 195 196 IMS Parallel Sysplex Migration Planning Guide Chapter 20 Recovery Procedures We discuss some possible recovery procedures here 20 1 Image Copies IMS has four methods of image copying databases These are Database Image Copy DFSUDMPO Concurrent Image Copy DFSUDMPO with CIC option Online Database Image Copy DFSUICPO Database Image Copy 2 DFSUDMTO 20 1 1 Database Image Copy DFSUDMPO The Database Image Copy utility without the CIC parameter produces clean image copies That is these copies are not made while updates are being made to the database DBRC authorizations enforce this
23. That is discontinue use of this system in the sysplex or Rebuild the structure on a CF to which all systems have access f the CF connection is repaired or if the structure is rebuilt the connection of IMS to the IRLM will be automatic Back out abended batch data sharing update jobs Restart batch data sharing jobs 20 13 CF Connection Failure to a DEDB VSO Structure 204 When connectivity from an IMS to a DEDB VSO structure fails the actions depend on the availability of a second structure for the area If there is another structure all IMSs discontinue using the structure with the lost connectivity The remaining structure is used to support sharing If there is not another structure the area is stopped in each IMS which loses connectivity Their connections become failed persistent connections Sharing of the structure is continued only by the IMSs that continue to have connectivity The IMSs that no longer have connectivity might have committed updates that have not been written to the structure or DASD These updates will be applied when connectivity is restored Cls containing these updates will remained locked until then IMS Parallel Sysplex Migration Planning Guide 20 13 1 Procedure with Connectivity to a Second Structure If sharing continues with a second structure immediate action is not required The use of two structures can be reinstituted after all IMS subsystems close the area The next tim
24. There are several alternatives that can be used to manage queue buildup when using shared queues The messages on the shared queue structures can be deleted by deleting the structures on the coupling facility This does require that all CQS address spaces be terminated before the structures can be deleted IBM s IMS Message Requeuer V3 product number 5655 136 can be considered for use to restore selected queues after deleting the shared queues structures Structure deletion of course requires an outage of all of the IMSs who are members of the same shared queues group This alternative is viable when true continuous availability is not required and a periodic planned outage can be scheduled on a regular basis Actively monitor and delete old messages from the structures using the commands described above to prevent the shared queues structures from Chapter 8 IMS TM Network Considerations 61 becoming full This monitoring deletion of messages can be implemented using an automated operator program Other automated operation tools can also be useful This second alternative is for those IMS users who want to achieve true continuous availability 8 5 Conversational Transaction Processing The SPA pool pool size limit was specified with the SPAP keyword on the IMS execution procedure in previous releases has been eliminated with IMS ESA V6 SPAs are now stored with the input and output messages associated with conve
25. These are the potential conflicts for KSDS indexes that are explained in step 9 Implement another IMS subsystem This implements actual data sharing It might create new lock conflicts additional lock processing and buffer invalidations Chapter 11 Data Sharing Enablement 115 11 8 IMS Procedures for Data Sharing IMS procedures should be reviewed when implementing data sharing The Table 2 identifies the IMS procedures PROCs and parameters which must be reviewed prior to migration to data sharing In some cases they might need to be changed RGSUF must be specified on the IMS or DBC procedure Other parameters for the IMS and DBC procedures can be specified in the IMS system definition in the IMS or DBC PROC or in member DFSPBxxx We recommend using DFSPBxxx Table 2 Page 1 of 3 IMS Procedures Summary PROC PARAMETER COMMENTS NAME DBBBATCH All The assumption is that IMS batch jobs currently using DLIBATCH block level data data sharing will continue to do so and that IMS batch jobs not using block level data sharing will not be changed to use it Batch jobs not using data sharing do not require changes to their execution parameters The following parameters are for block level data sharing jobs They also apply to executions of the Batch Backout utility IRLM This specifies that the IRLM is to be used The value must be Y for data sharing IRLMNM This is the MVS subsystem name for the IRLM The value
26. UOW locks are requested when DEDB UOWs are read by a utility or HSSP process They are also requested by other applications using an area when an HSSP or utility process is active for the area These locks are requested for all SHARELVLs but only those for databases with a SHARELVL of 3 are placed in the CF 11 11 1 6 Other Locks There are several other types of locks that are requested by IMS ina data sharing environment These include command locks and data set reference locks The number of requests for these locks is typically a very small percentage of the total lock requests Thus they rarely if ever have an important effect on data sharing overhead 11 11 1 7 Processing Unlock Requests When unlock requests are processed by the IRLM it must access the CF to release locks in the lock structure IMS can release one or more locks with one unlock request In any case the IRLM makes only one access to the CF to process up to 128 locks in an unlock request If more than 128 locks are released in one unlock request a CF access for each 128 locks is required An example of unlocking multiple locks is the unlock request made by IMS when an application program reaches a sync point It releases all of its locks with one request 11 11 2 IMS CF Access IMS accesses the CF for shared full function databases and shared shared DEDB VSO areas 11 11 2 1 Full Function VSAM The VSAM cache structure is accessed for VSAM database data sets when the
27. USERVAR DALLASP is to be used to distribute the logon requests between DALLAS1 and DALLAS2 see 9 2 Network Workload Balancing on page 66 2 Change the USSTAB entry for DALLAS from DALLAS USSCMD CMD LOGON USSPARM PARM APPLID DEFAULT DALLAS to DALLAS USSCMD CMD LOGON USSPARM PARM APPLID DEFAULT DALLASP In this manner the logon requirements are met without requiring any changes to the SLUTYPEP programs or the end user 3270 logon process Chapter 8 IMS TM Network Considerations 63 8 9 VTAM Model Application Program Definitions IMS TM users will find it advantageous to use VTAM model application program definitions in a Parallel Sysplex These definitions provide two capabilities First they allow one VTAM definition to be used for multiple IMS systems Second they make it easy to open a VTAM ACB on any VTAM in the sysplex Model application program definitions are created by specifying one or more wildcard characters in the name field of the APPL definition statement in VTAMLST An asterisk is used to represent zero or more unspecified characters question mark is used to represent a single unspecified character Any ACB whose names can be built from these specifications can be opened when the model application program is active The same model application program be active on multiple VTAMs simultaneously Without the use of model application program definitions moving an IMS system between systems
28. When the percentage of primary structure data elements exceeds a user specified threshold overflow processing is invoked If the CFRM policy contains an INITSIZE for the structure and the size has not yet reached the SIZE value an alter of the structure is done The size is increased to reduce the percent of data elements in use by 20 For example if the threshold were 70 percent the alter would increase the size of the structure and the number of data elements so that only 50 percent of the data elements would be in use This process is repeated if the threshold is reached again When the size of the structure reaches the CFRM policy SIZE specification overflow processing builds the overflow structure and moves some messages to it This assumes that the optional overflow structure has been requested Movement of more messages will occur if the primary structure reaches the threshold again This will continue until both structures are full Eventually puts to the structures might have to be rejected due to lack of space for them Overflow processing is based on the number of data elements in use If there are plenty of data elements but all list entries are in use no more messages can be placed in the structure Nevertheless overflow processing will not be invoked Rebuild for Shared Queues Structures Alter is used to change the size of a shared queues structure Rebuild is used to move it or recover it Alter can be invoked for a share
29. accumulation prior to the use of the IMS Database Recovery utility but this is not unique to disaster recovery Chapter 20 Recovery Procedures 207 208 IMS Parallel Sysplex Migration Planning Guide Appendix Naming Convention