IMS Application Programming Techniques

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1 IMS pplication Programming Techniques Kenny Blackman IBM 8/02 /2010 Session

2 and Data Independence pplication program MSK TP I/O-LT PCB Status Code DEVICE IB Return/Reason Code PSB DBD MSK DT BSE PCB Status Code NME DDRESS PYROLL 2

3 pplication Interface Block (IB) n application program can refer to a PCB by a given NME, not an address (PCBNME is 8 bytes). For the I/O-PCB, the name is 'IOPCBbbb' For DB-PCB, the name is specified in the PSBGEN: PCBNME=... parameter on PCB macro LIST=Y N - Display PCBNME in PSB listing? Most DL/I calls can be issued in two ways: Using a PCB (standard technique): CLL xxxtdli ( <count>,func,pcb,i/o RE,... ) CEETDLI Using an IB (new technique): CLL IBTDLI ( <count>,func,ib,i/o RE,... ) ERTDLI CEETDLI 3

4 lternate PCBs I/O PCB RECEIVE Lterm LTERNTE Response PCB LTERM=Lterm B Lterm B Lterm B LTERNTE Express PCB C C Modifiable LTERNTE PCB PROGRM D PROGRM D 4

5 IMS pplication Program Runtime Environments pplication Programs SUPPORTED BY IMS TM/DB CTL STND LONE IMS TM CONTROL REGION (CTL) MESSGE REGION (MPP,IFP,JMP) BTCH MESSGE Driven PROCESSING (BMP) BTCH Non-MESSGE Driven PROCESSING (BMP,JBP) DB BTCH REGION (DLI) TM BTCH REGION (DB2) FUNCTIONS QUEUING SCHEDULING LOGGING I/O - DT BSE - TERMINL SCHEDULED BY ONLINE DB'S OS/VS FILES MSG Q I/O PCB IMS YES NO YES YES USER YES YES YES YES SOME PROGRMS RE INTER- CHNGEBLE USER NO YES NO OPTIONL 5

6 Message Queuing INPUT OUTPUT TRN MESSGE 1 REPLY 1 REPLY 3 MESSGE 2 B REPLY 2 B PPC MESSGE 3 REPLY 4 C IMS Connect MESSGE 4 C 6

7 Message Format Service /FOR 7

8 MESSGE FORMT SERVICE IMS MPP,JMP.IFP,BMP (DIF) (DOF) MESSGE FORMT SERVICE PPLICTION PROGRM FORMT LIBRRY FORMT POOL (MID) (MOD) MESSGE QUEUE DL/I CLL DIF - DEVICE INPUT FORMT DOF - DEVICE OUTPUT FORMT MID - MESSGE INPUT DESCRIPTOR MOD - MESSGE OUTPUT DESCRIPTOR 8

9 Call Sequence GET UNIQUE TRNCODE FIRST SEGMENT GET NEXT SEGMENT 2 SEGMENT N PROCESS MESSGE INSERT GO GET MESSGE SEGMENT 1 SEGMENT N GO BCK/RETURN IF NO MORE 9

10 Problem W/O Conversational Interactive program Processing requirement Need temporary storage Solution 1 DT DDITIONL REQUESTED DT Multi-screen input PGM USE SCREEN? 1. Data lost if screen cleared 2. More data sent over comm lines Solution 2 DT 3 DT 2 DT 1 PGM B UPDTE TEMP. DB? OR UPDTE PERM. DB? B 1. Complicates program logic 2. Multiple db retrievals and updates 3. Input error, pgm abend - Scratch temp db record - Backout perm db record 10

11 Conversational Solution - Scratch Pad rea B NME JOHN DOE DDRESS 123 MPLE CHIC ILL CCT CCOUNT OK ITEM QTY DESC 1 THING 2 BLUE 2 3 MESSGE REGION ORDER ENTRY PROGRM S.P WORK RE CONTROL REGION SP JOHN DOE THING..2 BLUE ITEM PRICE SHIP SUB TX.50 SHIP.50 TOTL

12 Conversational Call Flow GET UNIQUE GET NEXT DETERMINE WHT TO DO THIS TIME PROCESS INSERT INSERT GO GET NOTHER CONVERSTION SCRTCH PD RE SP LL ZZ SEGMENT SP LL ZZ SEGMENT LL ZZZZ TRNCODE USER DT VRIBLE FIRST SEGMENT OF CONVERSTIONL TRNSCTION LL ZZ DT (NO TRNSCTION CODE) 2 2 VRIBLE Note pplication Program cannot modify the first 6 bytes of the SP (LL and ZZZZ). IMS TM uses these fields to identify the SP 12

13 Programming Tips ll programs should be written to go back and get another message (GU I/O PCB) ('QC' status if none exist) Data base requests should be handled with the fewest number of calls Message processing programs should not do lengthy data base scans or updates Never issue file open/close operations - beware of COBOL "displays" and PL/I "put datas" Issue all message segment gets/inserts as consecutive calls if possible The PSB should be completely accurate in procopt's selected for each segment type Large, single segment replies take fewer calls and less overhead (check system standard for maximum size) Do not issue GN calls to the i/o pcb for single segment messages 13

14 IMS Managed Service Flow Program-to-Program Switch MSG-Q IMS-PGM Process Data ISRT LTPCB UOW1 MSG-Q IMS/IMSB(MSC) TRNB/PGM-B Process data ISRT IOPCB UOW2 14

15 WebSphere Process Server Managed Service Flow WebSphere Process Server BPEL SC Service IMS TM Resource dapter IMS Connect IMS MSG-Q IMS-PGM ISRT LTPCB UOW1a IMS-PGM-B ISRT IOPCB Global Transaction UOW1b UOW1 15

16 IMS Enterprise Suite Soap Gateway Business Events WebSphere Business Events/ Monitor IMS Soap Gateway IMS Connect IMS MSG-Q IMS-PGM ISRT LTPCB Event DT WebSphere Business Events WebSphere Business Monitor 16

17 synchronous Model MSG-Q IMS-pplT1 ISRT LTPCB Message + appl-token ISRT IOPCB Message+appl-token B RED_DT Message+appl-token PROCESS_DT IMS-pplT2 Message+ appl-token ISRT IOPCB MSG-Q Message+appl-token SEND_DT Message+appl-token 17

18 IMS synchronous via OTM IMS Connect IMS-ppl T1 Message+ ppl-token ISRT LTPCB ISRT IOPCB UOW1 IMS-ppl T2 Message+ appl-token ISRT IOPCB UOW3 OTM Descriptor TMEMBER TPIPE IMS Connect Message Socket B TCP/IP-B IMS TM R, IMS SOP Gateway or RYO Resume_TPIPE RED_DT CK Send-Data Message+appl-token UOW2 18

19 WebSphere MQ synchronous via OTM IMS Bridge IMS-pplT1 ISRT LTPCB OTM DFSYPRX0 TMEMBER TPIPE SEND_DT messages Queue B MB MQGET ISRT IOPCB UOW1 IMS/IMSB ppl-t2 messages MQCON MQPUT MQDISC Queue UOW2 UOW3 19

20 WebSphere MQ via ESF synchronous IMS-PGM MQCONN MQ-B MQPUT MQPMO_Syncpoint MQDISC B ISRT IOPCB UOW1 messages Queue MB MQGET MQDISC UOW2 20

21 Synchronous Model MSG-Q IMS-pplT1 Send Message WIT Receive Message ISRT IOPCB Message Message B RED_DT Message PROCESS_DT SEND_DT Message 21

22 CPI-C/PPC Synchronous MSG-Q IMS-PGM CMLLC llocate TP-B Type=NONE/CONFIRM/SYNCPT CMSEND SEND_DT CMRCV RECEIVE_and_WIT CMDEL Dellocate ISRT IOPCB Conversation Session B IMS/IMSB LU6.2 TP-B CMRCV RECEIVE CMSEND SEND_DT CMDEL Dellocate UOW1 22

23 User Written TCP/IP Synchronous IMS-PGM Socket Connect - TCP/IP-B WRITE_DT WIT RED_DT CLOSE ISRT IOPCB UOW1 datagrams Connection TCP/IP-B RED_DT Socket Connect -TCP/IP-C RED_DT WRITE_DT CLOSE B UOW2 23

24 WebSphere MQ via ESF Synchronous IMS-PGM MQCONN MQ-B MQPUT NO-SYNCPOINT MQDISC ISRT IOPCB WIT MQGET (NO)SYNCPOINT messages Queue B MB MQGET MQPUT MQDISC UOW1 UOW2 24

25 DB2 Stored Procedure via ESF Synchronous IMS-PGM EXEC SQL: CLL PROC ( :aaa : bbb DB2 SP ISRT IOPCB data User Defined Function (UDF) Web Service IMS Managed UOW1 25

26 IMS Java and DB2 ttach Facility IMS-PGM IMS-Java JMP/JBP JDBC : : DB2 SP CLL PROC ( :aaa : bbb ISRT IOPCB data User Defined Function (UDF) Web Service RRS Managed UOW1 26

27 IMS Synchronous ICL MSG-Q IMS-ppl ICL Send Message> 32K Buffer Receive Message>32K ISRT IOPCB UOW1 WIT-Callout Buffer OTM Descriptor TMEMBER TPIPE IMS Connect IMS-token Message Socket Socket IMS-token Message B TCP/IP-B IMS TM R, IMS SOP Gateway, User-Written Resume_TPIPE RED_DT IMS-token Message CK SEND_DT IMS-token Message 27

28 Universal Drivers System z Distributed WS (any platform) WS Linux z Universal DB Resource dapter JC 1.5 Type 4 IFL Linux IMS Universal Drivers Universal DB Resource dapter JC 1.5 Type 4 T C P I P IMS Connect z/os IMS ODBM IMS DB CICS Type 4 Universal JDBC DLI Type 2 JDBC Type 4 DLI ny Java Runtime Platform WS/z Type 4 Universal DB Resource dapter JC 1.5 Type 2 z/os B IMS ODBM IMS DB DB2 Type 4 Universal JDBC DLI Type 2 Network Clients SN TCP/IP IMS TM IMS ppl Type 4 Universal JDBC Type 2 IMS DB 28

IMS TM MPP - JVM IMS 10 par PK82214 LE par PK99010 DB2 par PK93123 use ESF no RRS Server-Side Presentation Management Server-Side Business Logic TCP/IP or SN IMS TM Control Region IMS Connect IMS

29 IMS TM MPP - JVM IMS 10 par PK82214 LE par PK99010 DB2 par PK93123 use ESF no RRS Server-Side Presentation Management Server-Side Business Logic TCP/IP or SN IMS TM Control Region IMS Connect IMS MPP/IFP Region IMS z/os Platform IMS pplication Server COBOL Java pplicat ion ClassforName(DLIDriver) get.connection(ims psb) Select From Where Close JDBC Drivers IMS BMP Region COBOL Java pplicat ion ClassforName(DLIDriver) get.connection(ims psb) Select From Where Close DLI / DB2 JDBC Drivers 29

30 XML DB Highlights - Decomposed data Retrieve - Compose XML document from any existing traditional database Insert - Decompose XML docs back into same DB Same data can be read by existing IMS applications TM, CICS, WS or DB2SP XML Document IMS Java JDBC IMS DB Traditional DB Traditional DL/1 pplication DL/1 HLDB, FF or DEDB 30

31 XML DB Highlights - Intact Data Insert/Retrieve/Delete new XML documents INTCT in new IMS databases Intact data is not expected to be understood by other IMS applications XML Documents span IMS segments Stored in Unicode TM, CICS, WS or DB2SP XML Document IMS Java JDBC IMS XML DB Secondary Indexes Root Overflow Segment s Index source Index source Side Segments Intact XML Docs HLDB, FF or DEDB 31

32 IMS pplication Programming techniques Summary IMS pplication Programming provides simple device/data independent model For online processing For Batch Processing 32

IMS Plays a Role in a System z Cloud

IMS Plays a Role in a System z Cloud Plays a Role in a System z Cloud Kenny Blackman - kblackm@us.ibm.com Suzie Wendler - wendler@us.ibm.com 3/13 /2012 Session 10814 Memory lane 1.Centralized Computing: 1960 Optimized for sharing, industrial