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.

Batches can be distributed to a cluster by the cluster controller in one or both of the following ways. (Apple Qmaster determines which way is the most efficient for specific batches, depending on the circumstances.)

Rather than actually moving segments, Apple Qmaster tells the service nodes which segments to read via the network, where to find them, and what to do with them. Below is an example of how one batch could be processed in an Apple Qmaster system.

Figure. Diagram showing the batch, the cluster controller, instructions to individual service nodes, and the processed output file.

In distributing batches, Apple Qmaster uses the technology built in to Mac OS X to locate services in a cluster on the same IP subnet and to dynamically share and receive information. Because the computers can continually transmit their current processing availability status, Apple Qmaster can distribute (load-balance) the workload evenly across the cluster.