Mod_job Submission From Cics

Introduction When we talk about CICS the only thing that comes to our mind is its wide usage for online transactions like inquiry, updating the database etc. Other interesting thing that one can do with CICS is submitting batch job (JCL) to JES (Job Entry Subsystem) using SPOOL files.

Introduction Continued …. CICS provides an interface to JES that allows us to submit JCL to the Internal Reader, which is done using SPOOLOPEN, SPOOLWRITE and SPOOLCLOSE commands. These commands can be used in JES2 or JES3 form of JES. Spool files directed to JES Internal Reader are treated as complete Job and executed.

SPOOLOPEN With SPOOLOPEN command, spool file is set up for SPOOLWRITE. The command for SPOOLOPEN: EXEC CICS SPOOLOPEN OUTPUT NODE(‘*’) USERID(‘INTRDR ‘) TOKEN(rp_token) RESP(rs_ field) NOCC END-EXEC.

SPOOLOPEN Continued …. NODE(‘*’) 

Destination node to direct the JCL. This is 8 bytes field. If the node

name

is less than 8 bytes, pad it

with spaces. TOKEN



The identifier returned by CICS for the spool file. The same token has to

be It is a bytes.

used for subsequent commands. mandatory field of 8

SPOOLOPEN Continued …. USERID



Is the name of the Internal Reader that is set to INTRDR. If it is less

than 8 RESP

bytes, pad it with spaces. 

It holds the return code, indicating success (0) or failure (>0) of

command NOCC

execution. 

To prevent use of the first characters for carriage control.

SPOOLWRITE The command for SPOOLWRITE: EXEC CICS SPOOLWRITE FROM(data-field) TOKEN(rp_token) FLENGTH(data_length) RESP(rs_field) END-EXEC.

SPOOLWRITE Continued ……. FROM TOKEN FLENGTH RESP

The data field that contains the line of JCL to be spooled.  The same 8 bytes of information as in SPOOLOPEN.  Length of the data being written to the SPOOL.  Response value. 

Spool files are sequential. Each SPOOLWRITE is treated as a new record. Once all the necessary lines of JCL are written to SPOOL, the task is released to the JES for processing by SPOOLCLOSE command.

SPOOLCLOSE EXEC CICS SPOOLCLOSE TOKEN(rp_token) RESP(rs_field) END-EXEC. TOKEN and RESP have the same functionality as mentioned in SPOOLOPEN/SPOOLWRITE.   Once the SPOOL is closed, JCL gets submitted to JES that acts like a normal Batch Job.

Prerequisites for using SPOOL • One should be aware of the Node for the system. It is the JES subsystem name defined within the system. • The System Initialization Table (SIT) should have SPOOL=YES.

Good to Have points • One should make use of RESP or NOHANDLE on all spool commands. After each OPEN, WRITE or CLOSE command one should check the RESP value. • Use of RESP2 is recommended. Additional information about some exception condition is returned in this field.

Notes • If the SPOOL is not closed explicitly, it gets closed at the time of transaction termination. But it is always a good idea to close it. • In newer versions of COBOL, FLENGTH in SPOOLWRITE is not mandatory. It will automatically pick up the length of the variable specified in the WRITE command.  

Sample Cobol II Program to submit JCL to JES IDENTIFICATION DIVISION. PROGRAM-ID.SPOOLTT. ENVIRONMENT DIVISION. DATA DIVISION. WORKING-STORAGE SECTION. 01 WS-SPOOLVARS. 05 WS-TOK PIC X(08) VALUE SPACES. 05 WS-RESP PIC S9(04) COMP. 05 WS-NODE PIC X(08) VALUE ‘J2SIG ‘. 05 WS-READER PIC X(08) VALUE ‘INTRDR ‘. 01 WS-I PIC 9(02) VALUE 1.  

Sample Program Continued …. 01 WS-JOBSTREAM. 05 WS-JOBSTMT PICTURE X(80) VALUE ‘//TLPSC001 JOB (0807LS01),’’EMP PROCESSING’’,’. 05 WS-JOBAUTH PICTURE X(80) VALUE ‘// CLASS=K,MSGCLASS=1,NOTIFY=TPE037’. 05 FILLER PICTURE X(80) VALUE ‘//*’. 05 WS-JOBSTEP1 PICTURE X(80) VALUE ‘//DELSTEP EXEC PGM=IEFBR14’. 05 WS-JOBSTEP2 PICTURE X(80) VALUE ‘//DD01 DD DSN=TPE037.TEST.ERROR,’. 05 WS-JOBSTEP3 PICTURE X(80) VALUE ‘// DISP=(,DELETE,DELETE), SPACE=(TRK,(1,1),RLSE)’. 05 FILLER PICTURE X(80) VALUE ‘//*’. 01 WS-JOBSPOOL REDEFINES JOBSTREAM PIC X(80) OCCURS 7 TIMES.

Sample Program Continued …. PROCEDURE DIVISION. 0000-MAIN-PARA. PERFORM 1000-OPEN-SPOOL THRU 1000-EXIT. PERFORM 2000-WRITE-SPOOL THRU 2000-EXIT UNTIL WS-I > 7. PERFORM 3000-CLOSE-SPOOL THRU 3000-EXIT. PERFORM 9999-STOP THRU 9999-EXIT. 0000-EXIT. EXIT. 1000-OPEN-SPOOL. EXEC CICS SPOOLOPEN OUTPUT NODE(WS-NODE) TOKEN (WS-TOK) USERID (WS-READER) RESP(WS-RESP) END-EXEC. IF WS-RESP NOT = 0 PERFORM 9999-STOP THRU 9999-EXIT END-IF. 1000-EXIT. EXIT.

Sample Program Continued …. 2000-WRITE-SPOOL. EXEC CICS SPOOLWRITE FROM(WS-JOBSPOOL(WS-I)) FLENGTH(80) TOKEN(WS-TOK) RESP(WS-RESP) END-EXEC. IF WS-RESP NOT = 0 PERFORM 9999-STOP THRU 9999-EXIT END-IF. ADD 1 TO WS-I 2000-EXIT. EXIT.  

Sample Program Continued …. 3000-CLOSE-SPOOL. EXEC CICS SPOOLCLOSE TOKEN (WS-TOK) RESP(WS-RESP) END-EXEC. IF WS-RESP NOT = 0 PERFORM 9999-STOP THRU 9999-EXIT END-IF. 3000-EXIT. EXIT. 9999-STOP. EXEC CICS RETURN END-EXEC. 9999-EXIT. EXIT. Note: To write the entire JCL, SPOOL is opened once. SPOOLWRITE is repeated for every line of JCL. Once all the lines are written to the spool, it is closed.

Sample Program Continued …. When the above program is executed in the CICS region, the following job is submitted to JES. //TLPSC001 JOB (0807LS01),’EMP PROCESSING’, // CLASS=K,MSGCLASS=1,NOTIFY=TPE037 //* //DELSTEP EXEC PGM=IEFBR14. // DD DSN=TPE037.TEST.ERROR, // DISP=(MOD,DELETE,DELETE),SPACE=(TRK,(1,1),RLSE) //*  

Advantages Transient Data Queues (TDQ) is another traditional way of CICS interface to JES. Shortfalls of TDQ : • Single-threading queuing mechanisms within applications to avoid interspersing one user's JCL with that from another. • Performance problems due to high transaction volumes. Both these problems are well handled in CICS-JES Spool as each user is assigned a unique token that in turn permits multithreading.  

Advantages Transient Data Queues (TDQ) is another traditional way of CICS interface to JES. Shortfalls of TDQ : • Single-threading queuing mechanisms within applications to avoid interspersing one user's JCL with that from another. • Performance problems due to high transaction volumes. Both these problems are well handled in CICS-JES Spool as each user is assigned a unique token that in turn permits multithreading.