Defining and initializing the global catalog
The global catalog is a VSAM key-sequenced data set (KSDS) is used to store start type information, location of the CICS® system log, resource definitions, terminal control information and profiles.
Before you begin
- You must ensure that the REGION parameter on your CICS jobs is high enough to cope with the increase in buffer storage used for the global catalog, because this storage comes out of region storage not EDSA. For details, see Sizing buffer space for the global catalog data set.
- Estimate the amount of space needed in your global catalog to keypoint installed resource definitions, table entries, and control blocks. You must regularly review your space usage to ensure that extents are not running too close to the limit for your environment. For details, see Calculating the amount of space for the global catalog.
About this task
You can define and initialize the CICS global catalog in two ways. You can use the sample job as described below, or you can use the CICS-supplied job, DFHDEFDS.
If you need to perform a cold start, do not delete and redefine the global catalog data set. If you were to delete and redefine the global catalog, CICS would perform an initial start, and all recovery information for remote systems would be lost. When remote systems reconnected, CICS would inform them that it had lost any information that they needed to resynchronize their units of work, and messages would be produced to record the fact, on both the local and the remote systems. Instead, to specify that the next start should be cold, use the DFHRMUTL utility with the SET_AUTO_START=AUTOCOLD option. For more information, see Reusing the global catalog to perform a cold start.
Procedure
You can edit the sample job as follows:
Example job to define and initialize the global catalog
In the example JCL, the high level qualifier (CICSTSnn.CICS) assumes the release level of CICS TS 6.2. You must adapt it for your own CICS release.
//GLOCAT JOB accounting info,,CLASS=A
//DEFGCD EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=*
//SYSIN DD *
DEFINE CLUSTER -
(NAME(CICSTS62.CICS.applid.DFHGCD) -
INDEXED -
CYLINDERS(n1 n2) -
FREESPACE(10 10) -
SHAREOPTIONS(2) -
RECORDSIZE(4089 32760) -
REUSE -
VOLUMES(volid)) -
DATA -
(NAME(CICSTS62.CICS.applid.DFHGCD.DATA) -
CONTROLINTERVALSIZE(32768) -
KEYS(52 0)) -
INDEX -
(NAME(CICSTS62.CICS.applid.DFHGCD.INDEX) )
/*
//INITGCD EXEC PGM=DFHRMUTL,REGION=1M
//STEPLIB DD DSNAME=CICSTS62.CICS.SDFHLOAD,DISP=SHR
//SYSPRINT DD SYSOUT=A
//DFHGCD DD DSNAME=CICSTS62.CICS.applid.DFHGCD,DISP=OLD
//SYSIN DD *
SET_AUTO_START=AUTOINIT
/*