Change some connection attributes and cancel outstanding AIDs.
SET CONNECTION >>-SET CONNECTION(data-value)--+------------------+-------------> +-ACQSTATUS(cvda)--+ +-CONNSTATUS(cvda)-+ +-ACQUIRED---------+ '-RELEASED---------' >--+----------------+--+-------------------+--------------------> +-AFFINITY(cvda)-+ +-EXITTRACING(cvda)-+ '-ENDAFFINITY----' +-EXITTRACE---------+ '-NOEXITTRACE-------' >--+------------------+--+-----------------+--------------------> +-PENDSTATUS(cvda)-+ +-PURGETYPE(cvda)-+ '-NOTPENDING-------' +-CANCEL----------+ +-FORCECANCEL-----+ +-FORCEPURGE------+ +-KILL------------+ '-PURGE-----------' >--+-------------------+--+------------------+------------------> +-RECOVSTATUS(cvda)-+ +-SERVSTATUS(cvda)-+ '-NORECOVDATA-------' +-INSERVICE--------+ '-OUTSERVICE-------' >--+-----------------+--+------------------+------------------->< +-UOWACTION(cvda)-+ +-ZCPTRACING(cvda)-+ +-BACKOUT---------+ +-NOZCPTRACE-------+ +-COMMIT----------+ '-ZCPTRACE---------' +-FORCE-----------+ '-RESYNC----------'
Conditions: INVREQ, IOERR, NORMAL, NOTAUTH, SYSIDERR
For more information about the use of CVDAs, see CICS-value data areas (CVDAs).
The SET CONNECTION command allows you to change some of the attributes that define a connection. Control returns to the issuing program when the required operation has been scheduled. To get the operation started, it is necessary to relinquish control to CICS.
There are two main types of system connection:
A special form of IRC connection, used by the external CICS interface (EXCI) can exist between a CICS region and a non-CICS client program running in MVS, for example an MVS batch or TSO program. An EXCI connection connects the client program to a CICS region running in the same MVS image or within the same MVS/ESA sysplex.
The process of acquiring and releasing APPC sessions involves starting the LU Services Manager transaction CLS1. In order to pass data to the CLS1 transaction, CICS uses a temporary storage queue with the default data identifier (dataid) prefix DF. If temporary storage dataids with the prefix DF are defined as recoverable in your installation, you must follow the SET CONNECTION command by a SYNCPOINT command to end the logical unit of work and allow the SET CONNECTION command to complete.
The CVDA value is:
CVDA values are:
For further information about managing APPC connections, see the CICS Intercommunication Guide.
The CVDA value is:
The PENDING condition indicates the existence of recovery information (either shunted UOWs or decisions remembered for the partner) on a connection that has experienced a lognames mismatch with its partner. For a CICS Transaction Server for z/OS partner, a lognames mismatch indicates that the partner has performed an initial start. For a pre-CICS Transaction Server for z/OS partner, a lognames mismatch indicates that the partner has performed a cold start. In either case, the recovery protocol has been corrupted by a loss of log data at the partner.
It is not possible to set a connection to NOTPENDING state (forcing in-doubt and erasing NOFORGET UOWs) until this system has made contact with the partner and received a new logname from it.
Decisions for a whole connection can be forgotten, but that does not affect the memory of a decision for any other connection involved in the UOW.
The exchange lognames function and the resynchronization function are described in the CICS Intercommunication Guide and the Systems Network Architecture--LU6.2 Reference: Peer Protocols manual.
AIDs representing scheduled and allocated requests waiting in the local CICS system for the specified connection are canceled. However, TD AIDs with an associated triggered task already started are not canceled. In addition, the following CICS system AIDs are not purged unless FORCECANCEL is specified.
Remote delete AIDs | |
Remote scheduler AIDs | CRSR |
LU6.2 service manager 1 AIDs | CLS1 |
LU6.2 service manager 3 AIDs | CLS3 |
Remote schedule PURGE AIDs | CRSQ |
Resource manager resync AIDs | CRSY |
Autoinstall terminal delete AIDs | CATD |
Restart terminal delete AIDs | CATR |
Message DFHTF0101 is written to CSMT to indicate how many AIDs have been deleted for the connection and how many remain.
When a canceled SCHEDULE request is found to have a precursor in a remote CICS system; that is, the AID was originally scheduled in a remote system, this remote AID is canceled asynchronously.
In some extreme cases (for example, if an error occurs during backout processing), CICS might terminate abnormally.
For in-doubt and shunted UOWs, FORCEPURGE has no effect.
Examples of circumstances in which you might need to use it are:
For an MRO connection, all sessions are placed in service and the following occurs:
For an EXCI connection, all receive sessions (or "pipes") are placed in service and available for use by the client program.
For an ISC APPC connection, the LU Services Manager sessions are placed in service, thereby enabling the connection subsequently to be acquired.
For an ISC LU6.1 connection, all sessions are placed in service.
For a connection, all sessions are placed out of service (immediately if PURGE is specified, or when tasks have terminated if it is not) and the following occurs:
For an EXCI connection, all receive sessions (or "pipes") are placed out of service and are not available for use by the client program.
For an ISC APPC system, this option is valid only if the connection is RELEASED. The LU Services Manager sessions are placed out of service, and the connection cannot be ACQUIRED until it is placed INSERVICE again.
For an ISC LU6.1 connection, all sessions are released and placed out of service: immediately if PURGE or FORCEPURGE is specified; or when tasks have terminated if neither PURGE nor FORCEPURGE is specified. If the response to an INQUIRE CONNECTION command shows OUTSERVICE, it does not imply that the connection has been explicitly set as SET OUTSERVICE; in particular circumstances, you cannot reinstall this connection.
The operation is synchronous with setting the state of the UOW; that is, an INQUIRE UOW following a SET CONNECTION UOWACTION returns the new UOW states. CVDA values are: