Stopping DDF

You can stop the distributed data facility (DDF) if you have SYSOPR authority or higher.

To stop the DDF, use one of the following approaches:

• To stop DDF after existing requests complete, issue the STOP DDF command with the MODE (QUIESCE) option. This is the default option, and you should use it whenever possible.

  -STOP DDF MODE (QUIESCE)

  With the QUIESCE option, the STOP DDF command does not complete until all VTAM or TCP/IP requests have completed. In this case, no resynchronization work is necessary when you restart DDF. If any indoubt units of work require resynchronization, the QUIESCE option produces message DSNL035I. Use the FORCE option only when you must stop DDF quickly. Restart times are longer if you use the FORCE option.

• To force the completion of outstanding VTAM® or TCP/IP requests by canceling threads that are associated with distributed requests, issue the STOP DDF with the MODE (FORCE) option. Use this option only when you must stop DDF quickly.

  STOP DDF MODE (FORCE)

  When DDF is stopped with the FORCE option, and DDF has indoubt thread responsibilities with remote partners, message DSNL432I, DSNL433I, or both are issued.

  DSNL432I shows the number of threads that DDF has coordination responsibility over with remote participants who could have indoubt threads. At these participants, database resources that are unavailable because of the indoubt threads remain unavailable until DDF is started and resolution occurs.

  DSNL433I shows the number of threads that are indoubt locally and need resolution from remote coordinators. At the DDF location, database resources are unavailable because the indoubt threads remain unavailable until DDF is started and resolution occurs.

  To force the completion of outstanding VTAM or TCP/IP requests, use the FORCE option, which cancels the threads that are associated with distributed requests.

  When the FORCE option is specified with STOP DDF, database access threads in the prepared state that are waiting for the commit or abort decision from the coordinator are logically converted to the indoubt state. The conversation with the coordinator is terminated. If the thread is also a coordinator of downstream participants, these conversations are terminated. Automatic indoubt resolution is initiated when DDF is restarted.

• Another option for forcing DDF stop is by issuing the following VTAM command, where db2lu is the VTAM LU name for the local Db2 system.

  VARY NET,INACT,ID=db2lu,FORCE

  This command makes VTAM unavailable and terminates DDF. VTAM forces the completion of any outstanding VTAM requests immediately.

  When DDF has stopped, you must issue the following command before you can issue the START DDF command:

  VARY NET,ACT,ID=db2lu

DSNL005I - DDF IS STOPPING
DSNL006I - DDF STOP COMPLETE