DLISAS procedure

The DLISAS procedure initializes a DL/I separate address space (DLISAS).

If you specify LSO=S in the IMS procedure, automatically invoking the DLISAS procedure, the DD statements for the DL/I databases must be in the DLISAS procedure, not in the IMS procedure. Dynamic allocation members remain in the STEPLIB library.

For information about LSO=S, see Using a DL/I separate address space.

The DLISAS procedure is shown in Sample procedure to initialize a DL/I separate address space.

Usage

Other parameters in the IMS procedure that are applicable with the LSO=S option are DLINM, CSAPSB, and DLIPSB. DLINM specifies the partitioned data set (PDS) member name that IMS uses for the DLISAS procedure. The following list shows how the member name is assigned and how the name can be overridden.
  1. DLISAS is the default name
  2. The value specified on the DLINM= keyword in the IMSCTRL macro overrides the default name
  3. The value specified on the DLINM= keyword in the DFSPBxxx member of the IMS PROCLIB data set overrides the value specified in the IMSCTRL macro
  4. The value specified on the DLINM= keyword in JCL EXEC parameter overrides the value specified in the DFSPBxxx member of the IMS PROCLIB data set

The cataloged procedure (for the DLISAS) is stored in the IMS SDFSPROC data set during SMP/E processing. This member must be copied to SYS1.PROCLIB.

CSAPSB and DLIPSB specify the PSB pool sizes and override the values specified with the SASPSB parameter on the BUFPOOLS system definition macro.

Automatic initiation

An internally defined z/OS® START command is issued for the DLINM value and is coded to override the PARM=(DLS,&IMSID) procedure statement. The override defines the IMSID of the subsystem issuing the START, allowing a generic procedure to be used by multiple IMS control regions.

IMS does not issue the IMS READY message until the DLISAS successfully initiates. If the started DLISAS procedure is in error, you should correct and restart it.

When the DL/I address space connects to the IMS control region, the DLISAS procedure name is compared with the DLINM value. If they differ, the DLISAS abends.

Manual initiation

You can supply a START command (in member=DLINM of a PDS defined in the control region JCL //PROCLIB) instead of using the internally defined z/OS START command. Columns 1-5 must be START, or message DFS1930I is issued and the default process is performed.

You can specify two types of START commands:
  • START IMSRDR,MBR=DLISAS: the specified PDS member is read in as a job (rather than as a started task) through the z/OS internal reader.
  • START DLIAA,PARM=(DLS,IMSA): DL/I executes as a started task and DLIAA connects to IMSA.
Recommendation: Run your DL/I region as a started task, and specify the NODETAIL parameter in the SMFPRMxx member in SYS1.PARMLIB. Do not run your DL/I region as a job. While IMS supports running DL/I as a job, doing so can lead to storage shortages for long running DL/I regions that are managing a large number of databases. This is because z/OS SMF captures performance information in control blocks, which are kept in storage until the job terminates. These control blocks accumulate over time. A DL/I region that is active for a long period of time, and which is managing a large number of databases, can eventually run out of storage due to the SMF measurement data that is collected. This storage buildup does not occur with started tasks when NODETAIL is specified in the SMFPRMxx member.

For active and inactive ACBLIBs, the data set names and their concatenation order must be identical (same DSN and VOLSER) in the DLISAS procedure and in the IMS procedure.

The IMS PROCLIB data set must be defined in the DLISAS procedure and in the IMS procedure. Sometimes the same DLINM member is read from the IMS PROCLIB data set by both the control region and DLISAS.

Important: If the resources (such as DL/I databases) are RACF-protected, the user ID associated with DLISAS procedure must be authorized to access them. For more information about how to authorize the user ID, see IMS Version 15 System Administration.

Parameters

The following parameters are valid for the DLISAS procedure.

  • DPRTY=
  • IMSID=
  • NODE1=
  • NODE2=
  • RGN=
  • SOUT=
  • SYS2=

See Parameter descriptions for IMS procedures for descriptions.

DD statements

The following DD statements are valid for the DLISAS procedure.

In addition to these DD statements, DD statements for DL/I databases must be in the DLISAS procedure, not in the IMS procedure; add statements for data sets representing databases that are not to be dynamically allocated. DD statements for Fast Path databases remain in the IMS procedure.

  • IMSACBA DD
  • IMSACBB DD
  • IMSDALIB DD (optional)
  • PROCLIB DD
  • STEPLIB DD
  • SYSUDUMP DD

The IMSACBA and IMSACBB DD statements must be removed if you want to dynamically allocate the ACBLIB data sets through the DFSMDA member.

See DD statement descriptions for descriptions.

Sample procedure to initialize a DL/I separate address space

//       PROC RGN=64M,DPTY='(14,15)',SOUT=A,
//            IMSID=SYS3,SYS2=
//IEFPROC EXEC PGM=DFSMVRC0,REGION=&RGN,
//            DPRTY=&DPTY,PARM=(DLS,&IMSID)
//****************************************************
//*
//STEPLIB  DD DSN=IMS.&SYS2.SDFSRESL,DISP=SHR
//PROCLIB  DD DSN=IMS.&SYS2.PROCLIB,DISP=SHR
//****************** ACBLIB **************************
//*
//* THE SPECIFICATION OF THE ACBLIB DATASETS
//* IN THE DLI/SAS REGION PROCEDURE MUST
//* CORRESPOND EXACTLY WITH THE SPECIFICATION
//* IN THE CONTROL REGION JCL. THE IMSACBA AND
//* IMSACBB DD STATEMENTS MUST BE REMOVED IF YOU
//* WISH TO DYNAMICALLY ALLOCATE THE ACBLIB DATA
//* SETS THROUGH THE DFSMDA MEMBER.
//*
//IMSACBA  DD DSN=IMS.&SYS2.ACBLIBA,DISP=SHR
//IMSACBB  DD DSN=IMS.&SYS2.ACBLIBB,DISP=SHR
//SYSUDUMP DD SYSOUT=&SOUT
//SYSABEND DD SYSOUT=&SOUT
//************ DATA BASE DD CARDS ********************
//*
//* USER MAY OPTIONALLY SUPPLY THE DD STATEMENTS
//* FOR THE ON-LINE DATA BASES TO BE
//* INSERTED HERE PRIOR TO ATTEMPTING
//* AN ON-LINE SYSTEM EXECUTION USING
//* THIS PROCEDURE.
//* IF NO DD STATEMENTS ARE SUPPLIED FOR
//* A DATA BASE, IMS ASSUMES THAT THIS
//* DATA BASE HAS BEEN DESCRIBED THROUGH
//* THE DFSMDA MACRO.