StorageTek Lifecycle Director DB2 Manager 312564001 Manual De Usuario

Descargar
Página de 189
 
 
DB2 Manager User Guide 
73 
 StorageTek 
Proprietary 
 
 
In the DB2 Manager environment, lack of available tape drives will cause the 
DB2 Manager control region to enter allocation recovery.  Issuing a reply of 
WAIT will now mean that the application issuing the SQL command which 
caused the tape allocation request will have to wait indefinitely for another job 
on the system to release a drive, before continuing. 
In this case, the end-user response time would be unpredictable.  For this 
reason, it is recommended that a reply of 'CANCEL' be made to the IEF238D 
message. This will be interpreted by DB2 Manager as a 'drive unavailable' 
condition, and the retrieval request will be rejected with a ‘resource 
unavailable’ condition or optionally queued internally (if a non-zero value has 
been specified for the TAPEWAIT parameter in the TAPECNTL parameter 
library member).  In this latter case DB2 Manager will retry the request until a 
tape drive becomes available or until the TAPEWAIT interval is exceeded. . 
It is recommended that the reply of 'CANCEL' be performed by an automated 
operator reply facility, if present on the system, rather than via manual 
operator entry. In this way, there will be no delay between DB2 Manager 
receiving the retrieval request, and the rejection of the request with a 
‘resource unavailable’ condition. This will minimize delays to users in 
receiving notification of the unavailability of resources in performing the 
object access. 
Shutdown processing 
As an immediate shutdown does not allow outstanding migrated row storage 
and retrieval requests to complete, whenever possible the DB2 Manager 
control region should be shutdown normally (ie) use the SHUTDOWN 
operator command without the IMMED parameter. 
In this context, it is recommended that operators issue a summary status 
display command before issuing the DB2 Manager shutdown request. 
If there are any outstanding requests identified by the summary status 
display, these should be allowed to complete before issuing a normal DB2 
Manager shutdown request. If necessary, an immediate shutdown request 
may be issued in order to abnormally terminate outstanding requests, and 
perform DB2 Manager shutdown processing. 
Additionally, if the scheduler lock, as displayed from the summary status 
request, is constantly unavailable (ie. permanent LOCKED status), then an 
immediate shutdown should be issued, as a normal shutdown attempts to 
acquire this lock before proceeding. This situation, if it occurs, indicates an 
internal DB2 Manager error condition, and should be communicated to your 
DB2 Manager product support representative. 
In extreme cases, the DB2 Manager control region may be cancelled if 
required.  Canceling the control region has the following consequences: 
•  Any outstanding requests will be left unsatisfied in a wait state (ie) control 
will never be returned to the calling application. These applications will 
have to be abnormally terminated by an external source.