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Preface Introduction to Distributed Processing 9
Cluster Controllers
The cluster controller software acts as the manager of a cluster. The cluster controller
directs the distribution of batches within the cluster. It has the ability to determine the
best use of the cluster resources based on work and availability variables. (See “How
the Apple Qmaster System Distributes Batches,” next, for more details.) The cluster
controller is responsible for accepting batch submissions, maintaining and managing
the batch queue, and doling out the work to the appropriate service node. It also tracks
the status of all outstanding batches.
You make a computer available as a cluster controller by turning on the cluster-
controlling service in the Apple Qmaster pane in System Preferences.
QuickClusters
The QuickCluster feature of the Apple Qmaster distributed processing system is a
simple and automated alternative to creating and configuring clusters manually. For
more information about QuickClusters, see “Creating QuickClusters” on page 53.
Compressor AutoClusters
The AutoCluster feature in Compressor gives you an easy way to take advantage of the
distributed processing capabilities offered by Apple Qmaster without requiring a lot of
knowledge about how clusters are configured, setting up file sharing, and so on. For
more information about AutoClusters, see “Using Compressor AutoClusters” on page 23.
How the Apple Qmaster System Distributes Batches
The Apple Qmaster cluster controller determines the most efficient use of the cluster
resources. It makes this determination based on the availability of each service node
and the number of separable parts (described next) of the batch.
Because Apple Qmaster subdivides individual batches across different service nodes,
the work is shared and completed more quickly. And, because this method uses all the
service nodes as much as possible, you avoid under-utilizing your resources.