Client Fault Tolerance - Universal Connector Jobs - Requesting Restart
Requesting Restart
When a restartable Universal Connector command is initiated, it is either an initial instance or a restarted instance of a command ID.
The RESTART option is specified on the command line with parameter -restart. RESTART specifies whether or not the Universal Connector command instance is requesting a restart of a previous command ID. Possible RESTART values are yes, no, or auto.
The auto value specifies that if there is no existing command ID job on the SAP system, consider this Universal Connector execution the first instance. If there is an existing command ID job, consider this a restart of the command ID. The auto value permits automatic restart by eliminating the need to modify the RESTART value for the initial instance and restarted instance.
It is important to note that when using the RESTART auto value, Universal Connector will not start a new instance of a job on the SAP system if a job matching the job name/command ID exists in the SAP system. Universal Connector will continue to reconnect to the existing SAP job.
Without considering the behavior resulting from the use of RESTART auto, it may be possible for one to assume that a job has been run multiple times when, in fact, Universal Connector has been reconnecting to the same job instance. Informational messages are printed by Universal Connector to standard error to indicate the reconnected status but, if the message level is not set to info, the messages will not be seen.
Controlling Auto Restart
Misunderstanding the auto restart behavior described above can potentially have serious consequences. For this reason, the ALLOW_AUTO_RESTART lets you allow or disallow the use of auto restart. You can make this specification in the Universal Connector configuration file and override it on the command line.