Restart

SESAM/SQL and openUTM perform a synchronized restart.

SESAM/SQL needs the data on the processing status of the DB transactions contained in the transaction log files (TA-LOG1 and 2, WA-LOG, DDL-TA-LOG) to do so. openUTM obtains information on open or completed openUTM transactions from the KDCFILE file (containing data on the progress of the openUTM application).

The SESAM/SQL-DBH should always be terminated using the (default) administration statement STOP-DBH UTM-SESSION-INFO=*KEEP (see the “ Database Operation” manual) to make sure that both SESAM/SQL and openUTM have all the information needed for a synchronized restart:
STOP-DBH UTM-SESSION-INFO=*DELETE rolls back all open transactions, closes all logical files and deletes the restart information. The UTM-SESSION-INFO=*KEEP parameter causes the WA-LOG file to remain active and the restart information it contains to be retained. Open transactions are also rolled back and the logical files are closed.

openUTM cold start and openUTM warm start

• An openUTM application that was terminated normally using KDCSHUT performs a cold start when the application is started again (see the openUTM “ Generating and Handling Applications” manual).

• If no orderly KDCSHUT was executed, a warm start is carried out the next time the application is started.
  A warm start is only successful if the DBH was loaded before. During the synchronization phase, the DBH must be able to supply information on transactions that were not terminated and that were PENDing when the system aborted. That is why the DBH must not be stopped using STOP-DBH UTM-SESSION-INFO=*DELETE.

Depending on how the previous session was terminated, SESAM/SQL and openUTM perform a cold start or a warm start:

End of the previous session		Effect	Start of session
SESAM/SQL	/STOP-DBH UTM-SESSION-INFO= *DELETE	DBH sets “not active” flag in the WA-LOG file, information is deleted	Cold start
openUTM	KDCSHUT N	KDCFILE contains restart information 1	Cold start
SESAM/SQL	/STOP-DBH UTM-SESSION-INFO= *DELETE	DBH sets “not active” flag in the WA-LOG file, information is deleted	Cold start 2
openUTM	aborted with error	KDCFILE contains restart information 3	Warm start 2
SESAM/SQL	/STOP-DBH UTM-SESSION-INF0= *KEEP	WA-LOG file remains active, information is updated	Warm start
openUTM	aborted with error	KDCFILE contains restart information 3	Warm start
SESAM/SQL	aborted with error	WA-LOG file remains active, information is retained	Warm start
openUTM	aborted with error	KDCFILE contains restart information 3	Warm start

Table 69: Cold start and warm start of an SESAM/SQL openUTM application

¹KDCFILE may contain restart information on open transactions, but no information on transactions that were not terminated.

²Normally not executable because the SESAM/SQL DBH cannot respond to the Request status.³KDCFILE may contain restart information on open transactions and information on transactions that were not terminated.

³KDCFILE may contain restart information on open transactions and information on transactions that were not terminated.