CQS startup procedure

You can start CQS as a started procedure or with JCL. The started procedure JCL for CQS can execute either the CQSINIT0 or the BPEINI00 program.

A sample startup procedure called CQS can be found in the IMS PROCLIB data set. When using CQSINIT0, there is no change to the sample procedure shown in Sample Common Queue Server startup procedure using CQSINIT0.

JCL

The JCL for the CQS procedure using CQSINIT0 is shown in Sample Common Queue Server startup procedure using CQSINIT0.

When using BPEINI00, use the same procedure shown in Sample Common Queue Server startup procedure using CQSINIT0, but change the EXEC statement so that PGM=BPEINI00 is specified. You must also add the BPEINIT=CSQINI00 parameter, which identifies the CQS BPE initialization parameters module. A sample startup procedure using BPEINI00 is shown in Sample Common Queue Server startup procedure using BPEINI00.

Usage

Figure 1 shows the general relationship between execution parameters and members of the IMS PROCLIB data set. In the figure, CQSSL001 and CQSSL002 contain structure definition parameters that are unique to each CQS. CQSSG00A contains the structure definition parameters that are shared by all CQS address spaces connected to the shared queues.

Figure 1. Specifying IMS and CQS parameters

Parameters

You can specify the following execution parameters on the CQS startup procedure. Read the descriptions of the parameters to determine whether you want to accept the system defaults or tailor the system to fit the requirements of your environment.

• ARMRST=
• BPECFG=
• BPEINIT=CQSINI00
• CQSGROUP=
• CQSINIT=
• SSN=
• STRDEFG=
• STRDEFL=

Execution data sets

CQS uses two types of data sets, the system checkpoint data set and the structure recovery data set. Both of these data sets must be VSAM entry-sequenced data sets (ESDSs). These data sets are user data sets (and are not known to SMP/E).

CQS system checkpoint data set

Each CQS address space that is connected to a queue structure maintains a system checkpoint data set for each structure pair. Neither CQS address spaces or queue structures share the system checkpoint data set. The CQS initialization process dynamically allocates the system checkpoint data set.

Use the MVS/DFP DEFINE CLUSTER functional command to define the data set to the installation. The DEFINE CLUSTER function command and its parameters are described in z/OS® DFSMS Access Method Services for Catalogs.

     DEFINE CLUSTER                                            -
          (NAME (MSGQ.CHKPT)                                   -
          TRK(2,2) VOL (IMSQAV) NONINDEXED SHAREOPTIONS (2,3)  -
          RECSZ(505,505) REUSE CISZ (512))

CQS structure recovery data sets

CQS uses two structure recovery data sets per structure pair for its structure checkpoint processing.

Structure recovery data sets are not used for the resource structure.

When a structure checkpoint is requested, CQS dynamically allocates the structure recovery data sets. Structure checkpoint requests alternate between the two structure recovery data sets. During structure checkpoint processing all recoverable data objects on a structure are written to the structure recovery data sets. Thus, the size of each data set should be approximately the size of the primary structure plus the overflow structure to ensure that the entire structure fits in the data set.

Use the MVS/DFP DEFINE CLUSTER functional command to define the data set to the installation. The DEFINE CLUSTER function command and its parameters are described in z/OS DFSMS Access Method Services for Catalogs.

     DEFINE CLUSTER                                            -
         (NAME (MSGQ.SRDS1)                                    -
         TRK(45,5) VOL (DSHR03) NONINDEXED SHAREOPTIONS (2,3)  -
         RECSZ(32761,32761) REUSE  CISZ (32768)