IMS Version 9

/MODIFY

Format

Read syntax diagramSkip visual syntax diagram>>-+-/MODIFY-+--+-ABORT--------------------------------+-------><
   '-/MOD----'  +-COMMIT-------------------------------+
                '-PREPARE--| A |--+------------------+-'
                                  '-LTERM--ltermname-'

A:

|--+-ALL--+----------+--+----------+--+----------+-------------+--|
   |      '-PASSWORD-'  '-TERMINAL-'  '-TRANCMDS-'             |
   | .-------------------------------------------------------. |
   | V                                                       | |
   '---+-ACBLIB--+------+----------------------------------+-+-'
       |         '-BLDL-'                                  |
       +-FMTLIB--------------------------------------------+
       +-MODBLKS--+----------+--+----------+--+----------+-+
       |          '-PASSWORD-'  '-TERMINAL-'  '-TRANCMDS-' |
       '-RACF----------------------------------------------'

Environments and Keywords

Table 76 lists the environments (DB/DC, DBCTL, and DCCTL) from which the command and keywords can be issued.

Table 76. Valid Environments for the /MODIFY Command and Keywords
Command / Keywords DB/DC DBCTL DCCTL
/MODIFY X X X
ABORT X X X
COMMIT X X X
LTERM X X
PASSWORD X X X
PREPARE X X X
TERMINAL X X
TRANCMDS X X

Usage

/MODIFY controls the modification of IMS resources online. It switches the online environment from the active ACBLIB, FORMAT, MATRIX, and MODBLKS libraries to the inactive libraries containing the new or changed resource descriptions. See IMS Version 9: Administration Guide: System and IMS Version 9: Installation Volume 1: Installation Verification on how to create the inactive libraries before using this command. See IMS Version 9: Utilities Reference: System for information on using the Online Change utility. The descriptions of the resources and parameters for the /MODIFY command are shown in Table 77

Table 77. Resources and Parameters Available to the /MODIFY Command
Parameter Library Description
ACBLIB IMS.ACBLIBx 1 Contains database and program descriptors such as DMBs and PSBs.
FMTLIB IMS.FORMATx 1 Contains MFS maps produced by the MFS language utility and service utility. The FMTLIB parameter is not valid with DBCTL.
MODBLKS IMS.MODBLKSx, 1 IMS.MATRIXx Contains a subset of control blocks produced by IMS system definition and security definitions.
RACF   RACF in-storage profiles. The RACF parameter is not valid with DBCTL.
Note:
  1. × = A or B
  2. Use the SETROPTS RACLIST(CIMS) REFRESH command to refresh RACF updates.

The correct sequence for /MODIFY commands is PREPARE followed by COMMIT. If the online change is not to be completed, the /MODIFY ABORT command is used. The /MODIFY PREPARE command specifies which resources are to be changed or deleted. Depending on the parameters entered, the system will initiate quiescing of appropriate resources. COMMIT initiates the changes entered in a preceding PREPARE. If a previously entered /MODIFY PREPARE command is to be canceled, ABORT must be entered.

An IMS automated operator program can issue the /MODIFY PREPARE and /MODIFY ABORT commands, but it cannot issue the /MODIFY COMMIT command. Thus, you can automatically prepare or abort online change.

If this command is used to delete a database, IMS closes the database and makes it unavailable to programs. Also, if the database is authorized for DBRC, /MODIFY unauthorizes it.

Fast Path DEDBs are supported by the /MODIFY command, but Fast Path MSDBs are not supported.

In an IMSplex, /MODIFY is not supported if coordinated online change is enabled.

ABORT
Resets the status that was set by the /MODIFY PREPARE command after a /MODIFY PREPARE, or can be used if the /MODIFY COMMIT was not successful and the operator chooses not to attempt the online change at that time.
COMMIT
Brings all the newly defined resources online, updates the changed resources, and invalidates the deleted resources.

If ALL was specified on the /MODIFY PREPARE command, the ACBLIB, FMTLIB, and MODBLKS changes must be successful or the /MODIFY COMMIT will be rejected. When COMMIT is successful, the modifications will persist across all IMS restarts. If FMTLIB is entered, most new and in-progress requests will be queued for processing after the /MODIFY COMMIT command is completed.

If MODBLKS or ACBLIB is specified, work in progress in the system for changed or deleted ACBLIB and MODBLKS resources must be completed, or the /MODIFY command is rejected.

/DISPLAY MODIFY is used to display the work that was in progress prior to the entering of /MODIFY COMMIT.

IMS will prevent messages entered from terminals from being queued to transactions, but program-to-program switches from applications can still occur. Therefore, a /DISPLAY MODIFY command can indicate that no work is pending for the resources to be modified or deleted, but the /MODIFY COMMIT might be rejected. If this occurs, the new work must be allowed to complete and then the /MODIFY COMMIT command must be reentered.

/MODIFY COMMIT is rejected if:

Operator action might be required to prevent the preceding conditions. For example, if a program or database is scheduled, the operator should either wait until the program or database is finished before the /MODIFY COMMIT command is entered, or the operator should issue /STOP or /PSTOP for the associated transaction.

If IMS is in an IMSplex and Resource Manager (RM) is using a resource structure, the transactions being added by the online change are registered to RM if they are not already registered to RM. If any error occurs during the CSLRMUPD request to register the transactions, the /MODIFY or INITIATE OLC command will fail and IMS will be in a COMMIT2F state.

If a /MODIFY COMMIT command results in the COMMIT2F state, the command is rejected with a DFS178 message. A DFS3308 message is sent to the system console with the CSLRMUPD return/reason code. The IMS remains in a COMMIT2F state and the /MODIFY cannot be committed or aborted. The IMS must be cancelled and warm started as the online change is not complete.

PREPARE
/MODIFY PREPARE is not recovered across an emergency restart and must be reentered after restart if the /MODIFY COMMIT did not complete prior to an IMS failure.

The parameters in Table 78 are valid with /MODIFY PREPARE. The environments in which the parameters are valid are also shown in Table 78.

Table 78. /MODIFY PREPARE Parameters Environments
Parameter DB/DC DBCTL DCCTL
ACBLIB X X X
ALL X X1 X
BLDL X X X
FMTLIB X X
LTERM X X
MODBLKS X X X
PASSWORD X X X
TERMINAL X X
TRANCMDS X X
RACF X X
Note:
  1. Only applies to ACBLIB, MODBLKS, and BLDL.

ACBLIB
Quiesces the transactions to be changed or deleted and transactions that access databases or programs to be changed or deleted. ACBLIB members that are not found are displayed as CHANGED because a DDIR or PDIR exists in MODBLKS. Additions or deletions to ACBLIB require the MODBLKS parameter.
ALL
Indicates that /MODIFY PREPARE is to be performed for ACBLIB, FMTLIB, RACF, MODBLKS and BLDL.
BLDL
Causes information message DFS3498I to be issued for each PSB or DMB not found in ACBLIB. This message does not affect the success of the command.
FMTLIB
Indicates that there will be no restrictions on the use of MFS format blocks until the /MODIFY COMMIT command is entered.
LTERM ltermname
Specifies a logical terminal to receive lists of added, changed, or deleted resources.
MODBLKS
Causes IMS to prepare to bring the changes or deletions defined by the new system definition to IMS. Using MODBLKS also quiesces the transactions to be changed or deleted and transactions that access databases or programs to be changed or deleted.
PASSWORD
Is an optional keyword that can be specified in any combination with ALL or MODBLKS to add, but not delete, specific types of security definitions if they had not existed before. If ALL or MODBLKS is specified, the application of new security definitions will always be attempted based upon the prevailing security options in effect from the last IMS initialization.

Related Reading: See IMS Version 9: Administration Guide: System for more information on security definition.

RACF
Use of the RACF data space invalidates the IMS online change support for RACF with the /MODIFY command. The IMS online change support is still valid, though, when the RACF data space is not being used.

The message DFS3432 RACF PARAMETER INVALID IF RACF DATA SPACE IS USED is issued if the RACF parameter is used on the /MODIFY PREPARE command when the RACF data space is being used. You can use the RACF command SETROPTS RACLIST (classname) REFRESH to refresh the RACF resource profiles in the RACF data space without requiring the IMS applications to suspend work.

TERMINAL
Is an optional keyword that can be specified in any combination with ALL or MODBLKS to add, but not delete, specific types of security definitions if they had not existed before. If ALL or MODBLKS is specified, the application of new security definitions will always be attempted based upon the prevailing security options in effect from the last IMS initialization.

Related Reading: See IMS Version 9: Administration Guide: System for more information on security definition.

TRANCMDS
Is an optional keyword that can be specified in any combination with ALL or MODBLKS to add, but not delete, specific types of security definitions if they had not existed before. If ALL or MODBLKS is specified, the application of new security definitions will always be attempted based upon the prevailing security options in effect from the last IMS initialization.

Related Reading: See IMS Version 9: Administration Guide: System for more information on security definition.

Examples

Example 1 for /MODIFY Command

This is an example of a successful PREPARE, COMMIT sequence. First, the command /MODIFY PREPARE ALL is issued.

Entry ET:

  /MODIFY PREPARE ALL

Response ET:

  DFS3499I ACTIVE DDNAMES MODBLKSA IMSACBA FORMATA MODSTAT ID: 103

Explanation: The modifications are brought online to IMS during a subsequent successful /MODIFY COMMIT command. The ddnames of the active data sets and the current MODSTAT identifier are shown. This message is the normal response.

Example 2 for /MODIFY Command

This is an example of a prepare/commit/abort sequence.

Entry ET:

  /MODIFY COMMIT

Response ET:

  DFS3499I ACTIVE DDNAMES: MODBLKSB IMSACBB FORMATB MODSTAT ID: 104

Explanation: Successful COMMIT. ID is incremented and DDNAMES changed. This message is the normal response.

After the response is received from the second part of the successful PREPARE, COMMIT sequence, the command is issued to conclude the PREPARE, COMMIT sequence:

Entry ET:

  /MODIFY PREPARE ACBLIB MODBLKS TERMINAL

Response ET:

  DFS3499I ACTIVE DDNAMES MODBLKSB IMSACBB FORMATB MODSTAT ID: 104

Explanation: The modifications will be brought online to IMS during a subsequent successful /MODIFY COMMIT command. This message is the normal response.

Entry ET:

  /MODIFY COMMIT

Response ET:

  DFS3452I WORK IN PROGRESS FOR RESOURCES TO BE CHANGED/DELETED

Explanation: The /MODIFY COMMIT was rejected because changed/deleted resources have not been quiesced.

Entry ET:

  /MODIFY ABORT

Response ET:

  DFS058I  MODIFY ABORT COMMAND COMPLETED

Explanation: Status set by the /MODIFY PREPARE command is reset and the online change does not occur.

Example 3 for /MODIFY Command

This example shows the use of the LTERM keyword when adding, changing, or deleting Fast Path DEDBs or areas.

Entry ET:

  /MODIFY PREPARE ALL LTERM WTOR

Response ET:

  DFS3499I ACTIVE DDNAMES: MODBLKSA IMSACBA  FORMATA  MODSTAT ID:    1
  DFS3430I THE FOLLOWING MODIFICATIONS WILL OCCUR DURING /MODIFY ...
  COMMIT:
  DFS3430I DATABASE CALENDER      ADDED
  DFS3430I DATABASE NEWDD01       ADDED
  DFS3430I DMB      CALENDER      ADDED
  DFS3430I DMB      NEWDD01       ADDED
  DFS3430I DMB      DEDBJN23      CHANGED
  DFS3430I   AREA   DB23AR4       DELETED
  DFS3430I   AREA   DB23AR5       DELETED
  DFS3430I   AREA   DB23AR6       DELETED
  DFS3430I   AREA   DB23AR7       DELETED
  DFS3430I DMB      DEDBJN24      CHANGED
  DFS3430I   AREA   DB24ANU1      ADDED
  DFS3430I   AREA   DB24ANU2      ADDED
  DFS3430I   AREA   DB24ANU3      ADDED
  DFS3430I PSB      BMP255        CHANGED
  DFS3430I PSB      DDLTFPE4      CHANGED
  DFS3430I PSB      DDLTJN21      CHANGED
  DFS3430I PSB      DDLTRN20      CHANGED
  DFS3430I TRAN     TRAN255       CHANGED
  DFS3430I TRAN     TXCDRN20      CHANGED
  DFS3430I TRAN     TXCD255       CHANGED
  DFS3430I TRAN     TXCD255W      CHANGED
  DFS3430I SECURITY PASSWORD      NONE
  DFS3430I SECURITY TERMINAL      NONE
  DFS3430I SECURITY TRANCMDS      NONE
  DFS3430I SECURITY SIGNON        NONE
  DFS3430I SECURITY AGT           NONE
  DFS3430I END OF MODIFICATIONS

Explanation: The modifications will be brought online to IMS during a subsequent successful /MODIFY COMMIT command. These messages are the normal response.

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Copyright: IBM Corporation 1974, 2004 Copyright IBM Corporation 1974, 2004  timestamp Last updated: March, 2004