/ERESTART command

Subsections:

• Environment
• Syntax
• Keywords
• Usage notes
• Examples

Environment

The following table lists the environments (DB/DC, DBCTL, and DCCTL) in which you can use the command and keywords.

Syntax

Manual restart of an XRF alternate system

Use this command only after the active system issues message DFS3804I.

>>-+-/ERESTART-+--BACKUP---------------------------------------->
   '-/ERE------'           

>--+----------------------------------------+------------------><
   '-FORMAT--+----+--+----+--+----+--+----+-'   
             '-SM-'  '-QC-'  '-LM-'  '-MD-'     

Restart of IMS following loss of virtual storage only

>>-+-/ERESTART-+--+----------------------+--+--------------+---->
   '-/ERE------'  '-OPTION--+----------+-'  '-CHECKPOINT 0-'   
                            '-SYNCPLEX-'                       

>--+------------+--+-------+--+----------+---------------------><
   '-FORMAT--WA-'  '-NOBMP-'  '-OVERRIDE-'   

Restart of IMS following loss of virtual storage and message queue data set integrity

The message queues have not been dumped to the system log since the most recent cold start.

>>-+-/ERESTART-+--+----------------------+--+--------------+---->
   '-/ERE------'  '-OPTION--+----------+-'  '-CHECKPOINT 0-'   
                            '-SYNCPLEX-'                       

>--BUILDQ--+-------+--+----------+------------------------------>
           '-NOBMP-'  '-OVERRIDE-'   

>--+----------------------------------------------------+------><
   '-FORMAT--+-+----+--+----+--+----+--+----+--+----+-+-'   
             | '-SM-'  '-LM-'  '-QC-'  '-RS-'  '-WA-' |     
             '-ALL------------------------------------'     

Restart of IMS following /ERESTART failure of the database component

>>-+-/ERESTART-+--+----------------------+--COLDBASE------------>
   '-/ERE------'  '-OPTION--+----------+-'             
                            '-SYNCPLEX-'               

>--+--------+--+----------+------------------------------------->
   '-BUILDQ-'  '-OVERRIDE-'   

>--+----------------------------------------------------+------><
   '-FORMAT--+-+----+--+----+--+----+--+----+--+----+-+-'   
             | '-SM-'  '-LM-'  '-QC-'  '-RS-'  '-WA-' |     
             '-ALL------------------------------------'     

Restart of IMS following /ERESTART failure of communication component

>>-+-/ERESTART-+--+----------------------+--COLDCOMM------------>
   '-/ERE------'  '-OPTION--+----------+-'             
                            '-SYNCPLEX-'               

>--+-------+--+----------+-------------------------------------->
   '-NOBMP-'  '-OVERRIDE-'   

>--+----------------------------------------------------+------><
   '-FORMAT--+-+----+--+----+--+----+--+----+--+----+-+-'   
             | '-SM-'  '-LM-'  '-QC-'  '-RS-'  '-WA-' |     
             '-ALL------------------------------------'     

Restart of IMS following /ERESTART failure of both the database and communication components

>>-+-/ERESTART-+--+----------------------+--COLDSYS--+----------+-->
   '-/ERE------'  '-OPTION--+----------+-'           '-OVERRIDE-'   
                            '-SYNCPLEX-'                            

>--FORMAT--+-+----+--+----+--+----+--+----+--+----+-+----------->
           | '-SM-'  '-LM-'  '-QC-'  '-RS-'  '-WA-' |   
           '-ALL------------------------------------'   

>--+-+------------+--+------------+-+--+----------+------------><
   | +-TRANAUTH---+  +-CMDAUTH----+ |  +-MULTSIGN-+   
   | '-NOTRANAUTH-'  +-CMDAUTHE---+ |  '-SNGLSIGN-'   
   |                 +-NOCMDAUTH--+ |                 
   |                 '-NOCMDAUTHE-' |                 
   +-USER---------------------------+                 
   '-NOUSER-------------------------'                 

Keywords

The following keywords are valid for the /ERESTART command:

BACKUP

Indicates that the control region is an alternate system in an XRF environment. This command is required when performing manual restart.

BUILDQ

Is required for any restart from a failure in which message queue data set integrity was lost. When a checkpoint other than checkpoint 0 is specified, the checkpoint must be one at which the message queues were dumped to the system log. Message queue data set integrity has been lost if one or more of the data sets have been reallocated or reformatted. If a checkpoint is not specified, IMS selects the appropriate checkpoint from which to start.

If an /ERESTART BUILDQ command fails, and then you issue the /ERESTART CHECKPOINT 0, /ERESTART COLDCOMM, or /ERESTART COLDSYS command, messages in local queues are lost. However, IMS Message Requeuer (MRQ) can be used to recover local message queues.

In a shared-queues environment, the BUILDQ keyword is ignored because the message queue data sets are not used.

CHECKPOINT

CHECKPOINT is an optional keyword that identifies whether the restart should use the latest cold start system checkpoint that was taken by the IMS subsystem. If you do not specify this keyword, IMS determines the correct system checkpoint to use. If you do specify this keyword, you can specify only CHECKPOINT 0 to use the latest cold start system checkpoint.

CMDAUTH

Specifies that both signon (user identification verification) and command authorization for static and ETO terminals are in effect at the end of the emergency restart. (Command authorization is same as specifying RCF=S on the startup parameter.)

To specify CMDAUTH, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

CMDAUTHE

Specifies that command authorization for ETO terminals (same as RCF=S on the startup parameter) is in effect at the end of the emergency restart. CMDAUTHE also resets command authorization for static terminals, if it was set.

To specify CMDAUTHE, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

COLDBASE

Indicates a cold start of the database component, while performing an emergency restart of the communications component.

• If this keyword is used, you are responsible for the recovery of the databases. The Fast Path areas will not be redone and no backouts of inflight DL/I databases will be performed. If in-doubts exist, a batch backout run with the cold start option will backout inflight DL/I data. This will place both DL/I and Fast Path data in the aborted state.
• If this keyword is not used, the database component will be warm started.

If IMS is enabled to use the repository, IMS calls Resource Manager (RM) at the end of COLDBASE processing to read the change list, if one exists, for the IMS. The IMS change list is maintained by RM and is built if the IMPORT command with the SCOPE(ALL) keyword is issued while the IMS system is down. IMS imports the stored resource definitions from the repository for the resources and descriptors in the change list. The resources and descriptors in the change list are quiesced and not available for use until the stored resource definitions are imported from the repository. The change list for the IMS is deleted at the end of COLDBASE processing.

COLDCOMM

Indicates a cold start of the data communication component, while an emergency restart of the database component is being performed. This includes recovering Fast Path DEDBs, reloading MSDBs, backing out inflight changes to DL/I databases, and maintaining all existing indoubt data. COLDCOMM is used to get the DC network reinstated as soon as possible while databases are being recovered. As a result of COLDCOMM, all of the messages on the local message queue will be lost; inflight messages in shared queues are moved to the cold queue for later recovery. If this keyword is not used, the data communication component will be restarted.

If IMS is enabled to use the repository, IMS calls RM at the end of COLDCOMM processing to read the change list, if one exists, for the IMS. The IMS change list is maintained by RM and is built if the IMPORT command with the SCOPE(ALL) keyword is issued while the IMS is down. IMS imports the stored resource definitions from the repository for the resources and descriptors in the change list. The resources and descriptors in the change list are quiesced and not available for use until the stored resource definitions are imported from the repository. The change list for the IMS is deleted at the end of COLDCOMM processing.

COLDSYS

Indicates a cold start of both the database and the data communication components. An /ERE COLDSYS command differs from a /NRE CHECKPOINT 0 command in function, but the COLDSYS keyword is equivalent to, and replaces, the /NRE CHECKPOINT 0 DETACH command. The COLDSYS keyword is the newer syntax.

The use of the COLDSYS keyword causes the release of database authorizations for DBCTL SHARECTL (full DBRC data sharing) and releases any locks held by the subsystem in IRLM. This is the required form of cold start following a failure when using DBRC SHARECTL.

The SGN=, TRN=, and RCF= startup parameters can be overridden by the /ERESTART COLDSYS command using the keywords shown in the following table. This table lists the keywords and the startup parameters that those keywords can override and a brief description.

Table 2. Security keywords and their startup parameter equivalents

Keyword 1	Description	Startup parameter
CMDAUTH	RACF® command authorization on static and ETO terminals only	RCF=S
CMDAUTHE	RACF command authorization on ETO terminals only	RCF=C
MULTSIGN	Permits multiple signons for each user ID	SGN=M
NOCMDAUTH	Resets the command authorization on static and ETO terminals	Not RCF=S
NOCMDAUTHE	Resets the command authorization on ETO terminals only	Not RCF=C
NOTRANAUTH	Resets the transaction authorization.	Not TRN=F or Y
NOUSER	Resets user identification verification, transaction authorization, and command authorization	Not SGN=F or Y (G or Z becomes M) Not TRN=F or Y Not RCF=C or S
SNGLSIGN	Permits a single signon for each user ID	SGN=F and Y Not SGN=M (G or Z becomes F or Y)
TRANAUTH	Transaction authorization	TRN=F or Y
USER	Sets user identification verification	SGN=Y
Note: Valid only with the /ERESTART COLDSYS command.

If AUTOIMPORT=REPO or AUTOIMPORT=AUTO is specified and IMS is enabled to use the repository, the stored resource definitions are read from the repository during COLDSYS processing. The IMS change list is not processed during /ERE COLDSYS processing because all the resource definitions are imported as part of COLDSYS processing. If one exists, the change list in RM for the IMS being restarted with COLDSYS is deleted.

FORMAT

Specifies which queues or data sets should be formatted as part of the restart process when:

• A message queue or data set I/O error occurs.
• The size of a message queue or data set is to be changed.
• A message queue or data set is to be reallocated.
• Allocation of the WADS changes.

When queues or data sets must be formatted as part of the restart process, specify one or more of the following:

SM

Short-message queue

LM

Long-message queue

QC

Control record data set (QBLKs)

RS

Restart data set

WA

Write ahead data set

MD

MSDB dump data set (valid only for backup)

ALL

All message queues (SM and LM) and data sets (QC, WA, and RS). For DBCTL, this supports RS and WA only.

Any combination of SM, LM, QC, WA, MD, and RS can be specified; for example, FORMAT LM RS. When you specify ALL, do not specify SM, LM, QC, WA, MD, or RS.

In a shared-queues environment, the LM, SM, and QC parameters are ignored because the message queue data sets are not used. If you specify ALL, IMS does not attempt to format the message queue data sets.

The following table shows the environments in which the parameters are valid.

Table 3. /ERESTART FORMAT command parameter environments

Parameter	DB/DC	DBCTL	DCCTL
SM	X		X
LM	X		X
QC	X		X
RS	X	X	X
WA	X	X	X
MD	X		X
ALL	X	X	X

If the WADS must be reformatted during emergency restart, the ALL parameter can be used. IMS first closes the OLDS from the WADS and then reformats the WADS. If you generally use the ALL parameter during restart, do not be concerned that the WADS will not be available to close the OLDS.

MULTSIGN

Permits multiple signons for each user ID.

In an IMSplex with Resource Manager and a resource structure, if MULTSIGN conflicts with the single user signon definition for the IMSplex, a warning message is issued.

NOBMP

Specifies no backout of BMP updates occurs and all affected databases and programs are stopped.

If NOBMP is not specified, all updates made subsequent to the last commit point invoked by the active BMP programs are backed out of the database as part of the restart process.

NOBMP is ignored if no BMP programs were active at the time of the system failure.

NOCMDAUTH

Resets command authorization on static and ETO terminals.

NOCMDAUTHE

Resets command authorization for static and ETO terminals. The command authorization is reset for static terminals because the command authorization for static terminals cannot exist without the command authorization for ETO terminals.

NOTRANAUTH

Turns off transaction authorization. NOTRANAUTH is not the opposite of TRANAUTH. TRANAUTH sets transaction authorization and also turns on signon (user identification verification).

If you specify NOTRANAUTH, it will be rejected with an error message if TRN=F was specified as a JCL EXEC parameter.

NOUSER

Specifies that none of the following is in effect at the end of the emergency restart:

• Transaction authorization
• User identification verification
• Command authorization

OPTION

Specifies parameters that are in effect for the execution of the restart process.

The valid parameters for this keyword are as follows:

SYNCPLEX

Synchronize the startup of IMS systems after a multi-IMS failure. The option SYNCPLEX is entered on all the IMS systems that are to be synchronized. At the end of the restart process, the write to operator with replay (WTOR) message, DFS3067A, is issued. Once all of the IMS Systems are at this WTOR, they are now synchronized and can resume normal processing. The operator replies to the WTOR on each IMS and normal processing resumes

OVERRIDE

Is required only to restart the system after failure of power, machine, z/OS, or DBRC where IMS abnormal termination was unable to mark the DBRC subsystem record in RECON as abnormally terminated. IMS emergency restart will abort with message DFS0618A when DBRC indicates that the subsystem is currently active and that neither the OVERRIDE keyword nor the BACKUP keyword is present on the /ERESTART command. If there is any doubt about the status of an IMS system at restart time, the OVERRIDE keyword should not be used.

Attention: Use of the OVERRIDE keyword on a currently running IMS system can lead to database and system integrity problems.

SNGLSIGN

Permits a single signon for each user ID.

In an IMSplex with Resource Manager and a resource structure, if SNGLSIGN conflicts with the single user signon definition for the IMSplex, a warning message is issued.

TRANAUTH

Specifies both transaction authorization and user identification verification, with or without RACF.

To specify TRANAUTH, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

USER

Specifies user identification verification. User identification verification means that signon is required by static terminals. This keyword has no effect on ETO terminals because they are always required to sign on. User identification verification can be forced on by TRANAUTH or CMDAUTH.

To specify USER, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

Usage notes

This command can be issued to an IMSplex by using the Batch SPOC utility.

To override the security definitions, specify the COLDSYS keyword and the security keywords on the COLDSYS keyword.

The format for /ERESTART depends on whether the IMS system is an XRF alternate system. If the system is not an alternate system, the format also depends on the type of system failure that is associated with the termination and whether the message queues have been dumped to the system log since the most recent cold start.

All /ERESTART formats require an EOM indication to denote end-of-message; an EOS indication must be included for all segments that precede the last segment.

With Fast Path, the /ERESTART command loads the latest MSDB checkpoint data set and applies all MSDB changes up to the latest complete commit point. /ERESTART also ensures that DEDB updates created between the restart checkpoint and the latest complete commit point are applied. If the DEDB updates are not applied, they are queued for output. Output messages not acknowledged or not transmitted are also queued for output.

When IMS is initialized, the system parameters that are used for this initialization can come from the IMS system generation, from a PROCLIB member, or from EXEC statements that can override both the defaults and the PROCLIB members. Therefore, message DFS1929I is displayed showing the system parameters used for this particular initialization. The system parameters are also written to the job log.

When the /ERESTART command is issued without any keywords or with the COLDBASE or COLDCOMM keyword, IMS processes the system log during emergency restart processing to build runtime resource definitions from the log. The stored resource definitions from the RDDS or the IMSRSC repository are not used during emergency restart processing to build runtime resource definitions.

If IMS is enabled to use the repository, IMS calls Resource Manager (RM) at the end of emergency restart to read the change list for the IMS. The IMS change list is maintained by RM and is built if the IMPORT command with the SCOPE(ALL) keyword is issued while the IMS is down.

If a change list exists for the IMS that is being restarted, the database, program, transaction, and routing code resources and descriptors in the IMS change list and that apply to the IMS environment are quiesced and are not available for use until the stored resource definitions are imported from the repository.

After the IMS log is processed, IMS imports the stored resource definitions from the repository for the database, program, transaction, and routing code resources and descriptors in the IMS change list. It then applies the changes to the runtime resource and descriptor definitions in the IMS.

For the resources or descriptors that are in the IMS change list and that do not exist in IMS, the runtime resource definitions are created from the stored resource definitions in the repository. For the resource or descriptors that exist in IMS, the runtime resource definitions are updated with the stored resource definitions from the repository. The change list for the IMS is deleted at the end of the emergency restart.