/CHANGE Command: APPC Through NODE >>-+-/CHANGE-+--------------------------------------------------> '-/CHA----' >--+-APPC--+-TIMEOUT--#minutes-+-----------------------------------+->< | '-OUTBND--luname----' | | .-------. | | V | | +-CCTL--cctlname--PRTKN--+---prtkn-+-+--+-ABORT--+--------------+ | '-ALL-------' '-COMMIT-' | +-CPLOG--cp_log-------------------------------------------------+ | .----------------------------. | | V | | +-DESC--descriptor----+-LUNAME--luname---------+-+--------------+ | +-MODE--+-modename-+-----+ | | | '-NONE-----' | | | +-SIDE--sidename---------+ | | +-SYNCLEVEL--+-NONE----+-+ | | | '-CONFIRM-' | | | +-TPNAME--tpname---------+ | | '-TYPE--+-BASIC--+-------' | | '-MAPPED-' | +-DIR MFS-------------------------------------------------------+ +-FDR--TIMEOUT--#second-----------------------------------------+ | .-------. | | V | | +-LINK--+---link#-+-+--+-+-FORCSESS-+--+----------+-+-----------+ | '-ALL-------' | '-SYNCSESS-' '-COLDSESS-' | | | '-| A |----------------------' | '-NODE--+-nodename----+------------------------+--+-| A |-+---+-' | | .----------. | '-| B |-' | | | V | | | | '-USER--+---username-+-+-' | | '-ALL----------' | | .---------------. | | V | | '---+---+-nodename--+-+-+--+-| A |--------+-----------' | '-nodename*-' | '-+----------+-' '-ALL---------------' '-COLDSESS-' A: .-ON--. |--+-ASR--+-OFF-+-------+---------------------------------------| '-MODE--+-modename-+-' '-NONE-----' B: |--+-FORCSESS-+-------------------------------------------------| +-SYNCSESS-+ '-COLDSESS-'
/CHANGE Command: OUTBNDThrough USER >>-+-/CHANGE-+--------------------------------------------------> '-/CHA----' >--+-PASWD--pswdname--+----+--+----------+--pswdname------+---->< | '-TO-' '-PASSWORD-' | | .----------. | | V | | +-SUBSYS--+-subsysname--OASN----oasnname-+-+--RESET----+ | | .------------. | | | | V | | | | +---subsysname-+-----------------+ | | '-ALL----------------------------' | +-SURV--+-LNK-+--+-INTERVAL-+--#seconds----------------+ | +-RDS-+ '-TIMEOUT--' | | +-LOG-+ | | '-ALL-' | +-TRAN--tranname--MAXRGN--#regions---------------------+ | .-------. | | V | | +-UOR--+---prtkn-+-+--+-ABORT--+-----------------------+ | '-ALL-------' '-COMMIT-' | '-USER--username----AUTOLOGON----+-------+--+--------+-' '-| C |-' +-SAVE---+ '-NOSAVE-' C: .--------------------. V | |--nodename------+----------------+-+---------------------------| +-MODE--modename-+ +-LOGOND--ldname-+ '-ID--idname-----'
Table 21 lists the environments (DB/DC, DBCTL, and DCCTL) from which the command and keywords can be issued.
Command / Keywords | DB/DC | DBCTL | DCCTL |
---|---|---|---|
/CHANGE | X | X | X |
ABORT | X | X | |
APPC | X | X | |
ASR | X | X | |
AUTOLOGON | X | X | |
CCTL | X | X | |
COLDSESS | X | X | |
COMMIT | X | X | |
CPLOG | X | X | X |
DESC | X | X | |
DIR | X | X | |
FDR | X | X | |
FORCSESS | X | X | |
ID | X | X | |
INTERVAL | X | X | |
LINK | X | X | |
LOGOND | X | X | |
LUNAME | X | X | |
MAXRGN | X | X | |
MODE | X | X | |
NODE | X | X | |
NOSAVE | X | X | |
OASN | X | X | X |
OUTBND | X | X | X |
PASWD | X | X | X |
RESET | X | X | X |
SAVE | X | X | |
SIDE | X | X | |
SUBSYS | X | X | X |
SURV | X | X | |
SYNCLEVEL | X | X | |
SYNCSESS | X | X | |
TIMEOUT | X | X | X |
TPNAME | X | X | |
TRAN | X | X | |
TYPE | X | X | |
UOR | X | X | |
USER | X | X |
/CHANGE is a multisegment command used to change or delete internal resources within IMS.
All /CHANGE formats require an EOM indication to denote end-of-message; an EOS indication must be included for all segments that precede the last segment. See Multisegment Command Input for more detail on using EOS and EOM.
The timeout value (#minutes) must be between zero and 1440. If the timeout value is zero, APPC/IMS timeout will be deactivated.
A DFS34091 or DFS3491I message is issued after the /CHANGE APPC TIMEOUT command is issued to inform the operator of the new timeout value.
The luname value in the descriptor is set to blanks unless the LUNAME keyword is also specified. A network-qualified LU name is optional for the LUNAME keyword.
The MODE value in the descriptor is set to blanks unless the MODE keyword is also specified.
The TPNAME value in the descriptor is set to blanks unless the TPNAME keyword is also specified.
The conversation types are:
When IMS is initialized, IMS creates an MFS block primary directory based on the contents of all the $$IMSDIR members found. At the same time, IMS issues GETMAINs to acquire additional storage that is large enough to hold approximately 10% of the members in the active format library. While IMS is running, entries are only added to the dynamic directory, they are not deleted. Therefore, the dynamic directory continues to get larger until it runs out of space. When this happens, IMS can extend the amount of space in the dynamic directory to hold another 10%. IMS can extend the size of the dynamic directory a maximum of 9 times.
If you want to delete the in-storage (or index) entries from the dynamic directory without restarting IMS or performing an online change for the format library, use the /CHANGE DIR MFS command.
The timeout value (#seconds) must be at least 3 but no greater than 999.
IMS rejects this command if the active IMS subsystem is not connected to a Fast Database Recovery region.
Use the LINK keyword with FORCSESS, SYNCSESS, COLDSESS to override the system definition option defined for forcing resynchronization until the next /CHANGE LINK command or IMS cold start.
The COLDSESS keyword can be specified to terminate control blocks associated with the specified link or links and reset the link to COLD. COLDSESS should be used only after the /PSTOP command is issued and completes against the link or links and the links appear to be hung. If COLDSESS is specified, it should be used on both sides of the link or links. Gather documentation to determine why the link or links did not come down normally.
Automatic session restart is not necessarily activated for a link just because a status of ASR is displayed for that link. You must also have coded SONSCIP=YES on the APPL definition statement for VTAM when defining the network for the VTAM.
Changing ASR or mode table name for non-VTAM MSC links is invalid. If non-VTAM MSC links are referred to specifically in the /CHANGE LINK ASR or /CHANGE LINK MODE commands, they will be marked in error.
Automatic session restart is not necessarily activated for a node just because a status of ASR is displayed for that node. You must also have coded SONCSIP=YES on the APPL definition statement for VTAM when defining your network.
In an IMSplex, if global resource information is not kept in Resource Manager (RM), the change is applied locally. If global resource information is kept in RM, the change is applied globally.
A DFS0581 COMMAND COMPLETE EXCEPT message may be received if the node is temporarily in use by another task even if the criteria (node is terminated and idle) for successful completion of the command is met.
Changing ASR or the mode table name for VTAM 3270 nodes is invalid. If nodes of this type are referred to specifically in the /CHANGE ASR or /CHANGE MODE commands, they are marked in error.
/CHANGE USER AUTOLOGON SAVE changes the autologon information previously specified by a user descriptor, output creation exit routine (DFSINSX0), or signon exit routine (DFSSGNX0). The autologon change is saved. The autologon information includes the node name, the mode table, the logon descriptor, and the ID. If the Resource Manager is active, the user will be dynamically created if it does not already exist. The SAVE keyword must be specified. If SAVE is not specified, the command is rejected with message DFS1199.
The INTERVAL or TIMEOUT keyword identifies the new value in seconds and must be in the range 1 through 99. When /CHANGE SURV is entered on the active system, it becomes effective on both the active and alternate systems, if the alternate system is up. If entered on the alternate system, only the alternate system is changed.
It is recommended that surveillance be changed on the active system and allowed to take affect on the alternate system.
Additional considerations when changing the TIMEOUT values are shown in Table 22 Listed in the table are the TIMEOUT value requirements for certain systems where the command is entered on and the action taken for exceptions.
System the Command is Entered on | Requirement | Action Taken for Exceptions |
---|---|---|
Active | New timeout value must be >= twice the active interval value. | DFS3832 issued. Active timeout value forced to twice the active interval value. |
Alternate | Alternate interval value must be >= active interval value. | DFS3812 issued. Alternate interval value forced to active interval value. |
Alternate | New timeout value must be >= twice the alternate interval value. | DFS3832 issued. Alternate timeout value forced to twice the alternate interval value. |
Additional considerations when changing the INTERVAL values are shown in Table 23 Listed in the table are the INTERVAL value requirements for certain systems where the command is entered and the action taken for exceptions.
Related Reading: For more information on the TP profile, see the IMS Version 9: Administration Guide: Transaction Manager. For more information about the MAXPST= parameter, see the IMS Version 9: Installation Volume 2: System Definition and Tailoring.
The /DISPLAY TRAN command indicates whether a transaction is eligible for load balancing with a status of BAL, followed (in parentheses) by the current maximum number of regions that can be simultaneously scheduled.
Recommendation: Use /CHANGE UOR only when you are certain that no other resource managers would be adversely affected after IMS resolves the UOR.
If you specify ALL, the /CHANGE UOR command affects all units of recovery.
If global resource information is kept in Resource Manager, the change is applied globally when the SAVE keyword is specified. If SAVE is not specified in this environment, the command is rejected.
This set of examples shows that an INDOUBT unit of recovery can be aborted if the INDOUBT status cannot be resolved. The /CHANGE ... PRTKN command backs out changes made to the database.
Entry ET:
/DISPLAY CCTL CICS1 IND
Response ET:
CCTL PSEUDO-RTKN RECOVERY-TOKEN REGID PSBNAME STATUS CICS1 ATTACHED 000100C0 9FFA956B7AE24E00 BMP255 INDOUBT 00010040 9FFA9568FF594301 BMP255 INDOUBT *90067/113446*
Entry ET:
/CHANGE CCTL CICS1 PRTKN 000100C0 ABORT (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED DBS0699I REYNC ABORT COMPLETE FOR PSB BMP255...
Explanation: The INDOUBT unit of recovery whose pseudo recovery token (PRTKN) is 000100C0 has been aborted.
This set of commands illustrate how the ASR setting of a link can be modified by the /CHANGE command:
Entry ET:
/DISPLAY LINK 6
Response ET:
LINK PARTNER RECD ENQCT DEQCT QCT SENT 6 AL 0 0 0 0 0 ASR PSTOPPED IDLE COLD *90179/102004* IMSA
Explanation: Automatic Session Restart was defined for link 6 by system definition.
Entry ET:
/CHANGE LINK 6 ASR OFF (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Entry ET:
/DISPLAY LINK 6
Response ET:
LINK PARTNER RECD ENQCT DEQCT QCT SENT 6 AL 0 0 0 0 0 PSTOPPED IDLE COLD *90179/102126*
Explanation: Automatic Session Restart is not available for link 6
Entry ET:
/CHANGE LINK 6 ASR (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Explanation: The ASR parameter will default to ON.
Entry ET:
/DISPLAY LINK 6
Response ET:
LINK PARTNER RECD ENQCT DEQCT QCT SENT 6 AL 0 0 0 0 0 ASR PSTOPPED IDLE COLD *90179/102300*
Explanation: Automatic Session Restart is in effect again as a result of the second /CHANGE command.
Changing ASR for NODE or NODE/USER is similar to changing ASR for LINK. See the previous example for the commands used to change ASR.
Entry ET:
/DISPLAY NODE LUTYPEP1 MODE
Response ET:
NODE-USR TYPE DEF MODETBL ACT MODETBL LUTYPEP1 SLUP DEFRESP *90179/100630*
Explanation: DEFRESP is the mode table name defined for node LUTYPEP1 at system definition or logon descriptor or resource creation. The session is not active so the active mode table field (ACT MODETBL) is blank.
Entry ET:
/CHANGE NODE LUTYPEP1 MODE XXXXXXXX (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Entry ET:
/DISPLAY NODE LUTYPEP1 MODE
Response ET:
NODE-USR TYPE DEF MODETBL ACT MODETBL LUTYPEP1 SLUP XXXXXXXX *84179/100733*
Explanation: The default mode table name has been changed to XXXXXXXX by the previous /CHANGE command. The session is still not active so the active mode table field (ACT MODETBL) is blank.
Entry ET:
/DISPLAY NODE LUTYPEP
Response ET:
NODE-USR TYPE CID RECD ENQCT DEQCT QCT SENT LUTYPEP SLUP 00000000 37 37 37 0 37 IDLE *98276/153630*
Explanation: Node LUTYPEP is terminated warm after session received and processed 37 messages.
Entry ET:
/CHANGE NODE LUTYPEP COLDSESS (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Entry ET:
/DISPLAY NODE LUTYPEP
Response ET:
NODE-USR TYPE CID RECD ENQCT DEQCT QCT SENT LUTYPEP SLUP 00000000 0 0 0 0 0 IDLE COLD *98279/153630*
Explanation: Terminal and user blocks associated with node LUTYPEP have been cleared and the status has been reset to COLD.
Entry ET:
/CHANGE PASSWORD 1234 TO WXYZ (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Explanation: Password 1234 is changed to password WXYZ.
Entry ET:
/CHANGE SUBSYS DSN RESET (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Explanation: Reset all IN-DOUBT recovery units for subsystem DSN.
Entry ET:
/CHANGE SUBSYS ALL RESET (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Explanation: Reset all IN-DOUBT recovery units for all subsystems.
Entry ET:
/CHANGE SUBSYS ABCD OASN 99 685 2920 RESET (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Explanation: Reset IN-DOUBT recovery units identified by OASN numbers 99, 685, 2920 for subsystem ABCD.
This set of commands illustrates how SURVEILLANCE can be modified by the /CHANGE command.
Entry ET (Alternate system):
/DISPLAY HSB
Response ET (Alternate system):
RSENAME STATUS PHASE IMS-ID VTAM UVAR ACT-ID LOG-TIME DFSRSENM BACKUP TRK IMSB USERVAR IMSA 10:35:17 BACKUP SYSTEM ACTIVE SYSTEM SURVEILLANCE INTERVAL TIMEOUT STATUS INTERVAL TIMEOUT STATUS LOG 2 99 INACTIVE 2 99 INACTIVE LNK 4 99 INACTIVE 4 99 INACTIVE RDS 3 99 INACTIVE 3 99 INACTIVE TAKEOVER CONDITIONS - ALARM AUTO RDS LINK LOG *RDS LINK VTAM *IRLM *91226/103517*
Entry ET (Alternate system):
/CHANGE SURVEILLANCE LNK INTERVAL 3 (EOM)
Response ET (Alternate system):
DFS058I CHANGE COMMAND COMPLETED DFS3812I BACKUP LNK INTERVAL VALUE OF 3 HAS BEEN FORCED TO ACTIVE VALUE OF 4 DFS3811I LNK SURVEILLANCE INACTIVE: INTERVAL VALUE CHANGED FROM 4 TO 4
Explanation: An attempt to change the interval value was made by entering /CHANGE on the alternate system. The new alternate interval value was not >= the active interval value so IMS forced the interval to the active value and issued asynchronous message DFS3812. Asynchronous message DFS3811 indicates the status of the change following the above action by IMS.
The following commands illustrate how to change the maximum number of regions that can be simultaneously scheduled for a given transaction.
Entry ET:
/DISPLAY TRANSACTION SKS7
Response ET:
TRAN CLS ENQCT QCT LCT PLCT CP NP LP SEGSZ SEGNO PARLM RC SKS7 7 0 0 65535 65535 8 8 8 0 0 1 0 PSBNAME: DFSDDLT7 STATUS: BAL( 2) *90226/134816*
Explanation: The status of transaction SKS7 indicates it is eligible for load balancing (BAL) and that two regions can be simultaneously scheduled.
Entry ET:
/CHANGE TRANSACTION SKS7 MAXRGN 4 (EOM)
Response ET:
DFS058I CHANGE COMMAND COMPLETED
Entry ET:
/DISPLAY TRANSACTION SKS7
Response ET:
TRAN CLS ENQCT QCT LCT PLCT CP NP LP SEGSZ SEGNO PARLM RC SKS7 7 0 0 65535 65535 8 8 8 0 0 1 0 PSBNAME: DFSDDLT7 STATUS: BAL( 4) *90226/134845*
Explanation: The maximum number of regions that can be simultaneously scheduled for transaction SKS7 has been changed from 2 to 4.
The following commands illustrate the changing of a unit of recovery.
Entry ET:
/CHANGE UOR 010040 ABORT
Response ET:
DFS058I CHANGE COMMAND COMPLETED DFS0699I RESYNC ABORT COMPLETE FOR PSB STLDDTL1, PRTKN=00010040, TOKEN IMS2 0000000100000000 IMS2 *97226/134816*
Explanation: IMS backs out changes for pseudo recovery token 010040.
Entry ET:
/CHANGE UOR 010040 COMMIT
Response ET:
DFS058I CHANGE COMMAND COMPLETED DFS0699I RESYNC COMMIT COMPLETE FOR PSB STLDDTL1, PRTKN=00010040, TOKEN IMS2 0000000100000000 IMS2 *97226/134816*
Explanation: IMS makes changes for pseudo recovery token 010040 permanent.