Distributed Processing Setup Guide

If a Batch Is Interrupted
When a service stops suddenly while in the middle of processing an Apple Qmaster batch,
the cluster controller resubmits the interrupted batch in a way that prevents the
reprocessing of any batch segments that were complete before the service stopped. The
cluster controller delays resuming the batch for about a minute from the time it loses
contact with the service.
If a Batch Fails
When the service is running, but one batch fails to process, a service exception occurs.
When this happens, the cluster controller resubmits the batch immediately. The cluster
controller resubmits the batch a maximum of two times. If the job fails on the third
submission, the distributed processing system stops resubmitting the job. In Batch Monitor,
the job is moved to the History table, where the status column indicates that a failure
occurred.
Failure Notification
There are two different ways that the Apple Qmaster distributed processing system can
provide information about a problem.
Email Notification
When a processing service stops unexpectedly, Apple Qmaster sends a notification email
to the address that was entered in the Apple Qadministrator Cluster Preferences dialog
for that cluster. If no address was entered there, the email is sent to the address in the
Internet settings of the computer on which the cluster controller is enabled.
Note: Apple Qmaster does not currently support SMTP servers that require authentication.
Log Files for Individual Jobs or Batches
If a particular job or batch fails, a log file is generated that describes this failure. You can
find the name and location of this log file through Batch Monitor.
To find the name and location of a log file
1 Select the batch or job in the History table of the Batch Monitor window.
2 Click the Info icon.
If any log files were generated because of failures in the processing of the item, the names
and locations of those logs are shown.
Notification and Log Labels
The following table lists the service labels used in the email notifications and logs.
Notification labelProcessing service type
servicecontroller:com.apple.stomp.transcoderLocal Compressor service
servicecontroller:com.apple.stomp.transcoderxDistributed Compressor service
74 Chapter 6 Administering Clusters