APAR status
Closed as canceled.
Error description
5740xyr00 R230 R310 The information about DB2 with CICS Version 4 is contained in 3 Info. APARs: II07632, II07633 and II07634. Notice to Everyone Using DB2 with CICS Version 4 ================================================ The CICS-DB2 attachment facility is the part of the DB2 product that connects CICS to DB2. This attachment facility is provided on the product tapes of all releases of DB2. Now, the CICS Version 4 product provides its own CICS-DB2 attachment facility. This new attachment facility is shipped on the CICS product tape in order to take better advantage of CICS features and enhancements. It works with all currently supported releases of DB2, that is, DB2 2.3 and DB2 3.1. If you wish to connect to DB2 from CICS Version 4, you must use the new attachment facility, which is shipped with the CICS Version 4 product. DB2's old attachment facility is still shipped with the DB2 product in order to continue support for CICS Version 2 and Version 3. This notice covers the following topics: - Enhancements in the New CICS-DB2 Attachment Facility 1) The new attachment facility runs above 16M. 2) The resource control table has a two-byte suffix. 3) SQL programs can run in PLT initialization after DSN2COM0 has been run. 4) The CICS INITPARM can specify your RCT suffix and DB2 SSID defaults. 5) The DSNC STRT command can also specify both RCT suffix and SSID override. 6) Attachment facility traces provide more information. 7) The new attachment facility has some performance benefits over old attachment facility. 8) You can now easily identify waits for DB2 on CEMT I TAS and on DB2 formatted region dumps. 9) The resource control table provides three new options. 10) A recovery restriction has been removed 11) You can use the INQUIRE EXITPROGRAM command to prevent AEY9 abends. - How to Use the New CICS-DB2 Attachment Facility 1) Apply prerequisite apars. 2) Install DB2. 3) Set up CICS Version 4 CICS System Definition File (CSD). 4) Set up CICS Version 4 Initialization JCL. 5) Use INITPARM instead of DSNCRCTx to select resource control table (RCT) suffix. 6) Change your application programs if they reference old attachment facility module names (except DSNCLI, DSNCUEXT). Note: DSNCLI in SDFHLOAD instead of SDSNLOAD 7) Update any program list tables (PLTs) containing DSNCCOMx. 8) Change any applications which link to DSNCCOMx to start or stop the attachment facility. 9) Use INQUIRE EXITPROGRAM instead of EXTRACT EXIT. 10) Change trace IDs if explicitly coded in your RCT 11) Assemble the resource control table. 12) Use DSNC message explanations for DSN2 messages if you have not yet received the DB2 V3 Messages and Codes update. - New Messages ---------------------------------------------------------------- ENHANCEMENTS The attachment facility that is shipped with CICS Version 4 is very much like the old attachment facility that is shipped with DB2, except that the CICS Version 4 attachment facility contains the following enhancements. 1) The CICS-DB2 attachment facility modules and most of their control block storage reside above the 16M byte line of virtual storage. This reduces your virtual storage constraints. The attachment facility has also added the LINKEDITMODE options to the enable commands, so you may now specify TASKDATALOC(ANY) for your application programs that use SQL. 2) A two-byte resource control table suffix enables you to keep more copies of the resource control table and to have greater flexibility with your naming conventions. 3) You can now run SQL programs in PLT after DSN2COM0 has been run. This was not possible with the old attach. In the old attachment facility, CICS did not complete connection to DB2 until CICS had been completely initialized. 4) The old DSNCRCTx parameter on the CICS initialization JCL has been replaced by the CICS INITPARM parameter. You can specify the INITPARM on either the PARM= parameter of the EXEC PGM=DFHSIP statement of your initialization JCL, or in the SYSIN dataset. The default resource control table suffix is now 00. 5) At CICS initialization you can use either the INITPARM or the DSNC STRT command to select the resource control table suffix and/or the DB2 subsystem ID. The subsystem ID override is new. INITPARM - The INITPARM syntax is: INITPARM=(DSN2STRT='------------------------',------------> | | | | | | -rct suffix-- -,ssid-- -other- INITPARMs- For example, if you say INITPARM=(DSN2STRT='aa,bbbb'), you will use the resource control table named DSN2CTaa and you will connect to DB2 subsystem bbbb, regardless of what subsystem is specified in DSN2CTaa. Other examples: INITPARM=(DSN2STRT='22') RCT is DSN2CT22, no SSID override INITPARM=(DSN2STRT=',DSNA') Use default RCT, connect to DSNA (In this example the comma is used because the SSID is a positional parameter, and the comma indicates that no RCT suffix is specified.) INITPARM=(DSN2STRT='5,DSN',myparm='x') RCT is DSN2CT5, SSID is DSN (this example includes an INITPARM for another CICS application) DSNC STRT command: The syntax of the DSNC STRT command is now: DSNC STRT '------------------------> | | | | -rct suffix-- -,ssid-- The default of the DSNC STRT command has changed to what- ever was specified in the INITPARM. If nothing was specified in the INITPARM, the resource control table suffix default is 00 and the SSID defaults to whatever is specified in the SUBID field of the resource control table. Examples: DSNC STRT 22 Use DSN2CT22, SSID in INITPARM. (If no SSID was specified in INITPARM, use the SUBID in DSN2CT22) DSNC STRT ,DB2A Use INITPARM RCT suffix, connect to DB2A (As with the INITPARM, the comma is used as a placeholder to indicate that no RCT suffix is specified on the command). 6) The EXEC CICS ENTER TRACEID commands in CICS have been replaced with CICS system trace. - EXEC CICS ENTER TRACEID has a long pathlength, and the CICS system trace improves upon that. - Previously you had to have both the master trace flag on and the user trace flag on to get a CICS attach trace. Now you only have to set on the file control trace flag. You can do this by accessing the "components" option in the CICS CETR transaction, and setting the "FC" flag to 1 or 2. - Trace contains more data, including the addresses of the DSN2LOT, DSN2SUB and DSN2CCT control blocks. Exception traces and level 2 traces contain the entire DSN2LOT control block. 7) Other pathlength improvements include a) redesign of the timer mechanism which purges threads b) a performance improvement for CICS POST c) replacement of CICS WAIT EXTERNAL by the CICS XPI WAIT_MVS. 8) WAIT_MVS not only provides a shorter pathlength, it helps you identify DB2 waits, too. Both CEMT INQUIRE TASK and CICS formatted region dumps will indicate a task that is waiting to return from DB2. The example below shows the output of a CEMT INQUIRE TASK command. ----------------------------------------------------------- | INQUIRE TASK | | STATUS: RESULTS - OVERTYPE TO MODIFY | | Tas(0000151) Tra(DSNC) Sus Tas Pri( 255 ) | | ? Tas(0000161) Tra(XC05) Fac(1303) Sus Ter Pri( 001 ) | | Tas(0000162) Tra(CEMT) Fac(1302) Run Ter Pri( 255 ) | | | | | ----------------------------------------------------------- When you put a question mark (?) next to a specific task and then press enter, the CEMT output shows more detail about the task. In this example, it shows that task 161 is waiting to return from DB2: ----------------------------------------------------------- | INQUIRE TASK | | SYNTAX OF SET COMMAND | | Tas(0000161) Tra(XC05) Fac(1303) Sus Ter Pri( 001 ) | | Hty(DB2 ) Hva(CLOTECB ) Hti(000018) Sta(TO) | | Use(SYSADM ) Rec(X'A8B5FE112D54CA85') | | CEMT Set TAsk() | < All > | | < PRiority() > | | < PUrge | FOrcepurge > | | | | | ----------------------------------------------------------- A CICS formatted region dump also displays similar information when a task is waiting to return from DB2. The next example shows some of the columns from the dispatcher domain section of a CICS 4.1 formatted region dump. The task with a KE_TASK of 02BA9080 shows a "resource type" of DB2 and has a "resource name" of CLOTECB. CLOTECB is the name of the ECB that the task is waiting on. _____________________________________________________________ Normal formatting would display these columns on one line but due the more restrictive formatting in APARs the lines have been split to fit. DS_TOKEN KE_TASK TY S P PS TT RESOURCE RESOURCE ST TIME OF TYPE NAME SUSPEND 00020003 029D7C80 SY SUS N OK - TIEXPIRY DS_NUDGE SUSP 18:50:29.591 000C0005 029CAC80 SY SUS N OK - SUSP 18:11:22.030 000E0005 02B99080 SY SUS N OK - JCJOURDS DFHJ01A SUSP 18:39:39.377 00120007 02B99780 SY SUS N OK - KCCOMPAT SINGLE OLDW 17:02:12.991 00160005 02B99B00 SY SUS N OK - JCTERMN SUBTASK OLDW 17:01:56.319 00180003 029CA580 SY SUS N OK - ICMIDNTE DFHAPTIM SUSP 08:00:00.521 001A0003 029CA200 SY SUS N OK - TCP_NORM DFHZDSP OLDW 18:51:27.852 001C0003 03F03900 SY SUS N OK - ICEXPIRY DFHAPTIX SUSP 18:50:29.591 008A0005 02B92080 SY SUS N OK - JCJOURDS DFHJ02A SUSP 17:02:04.879 008E0001 02B13080 SY SUS N OK IN SMSYSTEM SUSP 18:47:49.156 0102006F 02BA9080 NS SUS Y OK - DB2 CLOTECB MVS 18:51:22.958 01040031 02BA9780 NS RUN 01060009 02B13B00 NS SUS Y OK - MVS 18:50:29.591 __________________________________________________________ 9) Three new resource control table parameters are available: TXIDSO, PLANI, and PURGEC. The new TXIDSO and PURGEC RCT parameters belong on the TYPE=INIT form of the RCT macro. TXIDSO Resource Control Table Option - The TXIDSO resource control table option allows suppression of some signons during thread reuse, and therefore prevents extraneous accounting records from being written. With the default of TXIDSO=YES, the attachment facility determines whether a new transaction may reuse an existing thread in this way: - If the plan name, authorization ID, and transaction ID are the same as the last transaction that used the thread, and if TOKENE is set to NO, then the transaction reuses the thread without any signon. - If the plan name is the same as that of the transaction that last used the thread, and - the authid has changed, or - TOKENE is YES, or - the transaction id has changed then the thread is reused following a signon. - If the plan name has changed, the thread is terminated and re-created. continued in II07633......
Local fix
Problem summary
Problem conclusion
Temporary fix
Comments
APAR Information
APAR number
II07632
Reported component name
PB LIB INFO ITE
Reported component ID
INFOPBLIB
Reported release
001
Status
CLOSED CAN
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
1994-02-18
Closed date
1994-06-06
Last modified date
2001-02-20
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Applicable component levels
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Document Information
Modified date:
14 December 2020