COGNOS Business Intelligence Series 7

Chapter 3: Control Processes
You control the processing resources allocated to a cube or report by adjusting the Process
Control settings, particularly Minimum Processes and Maximum Processes.
Minimum Processes
Minimum processes are the number of processes that remain running after they open. Keeping
processes open improves performance, particularly with cubes and reports that are hit frequently.
Maximum Processes
When a cube or report starts receiving more requests than available processes can handle,
PowerPlay Enterprise Server opens additional processes, up to the number you have defined as the
maximum for the cube or report. If the maximum is reached, the dispatcher starts queuing
requests until processes become available. By default, a queued request is deleted after 15 seconds.
By setting minimum and maximum processes, you can control the number of processes that occur
on each dispatcher. The number of processes does not have to reach its maximum value before
additional processes can be sent to a different dispatcher. When the number of hits on the cube or
report exceeds the Maximum Processes threshold, instead of queuing up requests, they are
forwarded to the mirror reference, which is free to immediately process more requests.
If you have a dispatcher that you want to act only as a router, that is, to only pass requests, you
can set the Maximum Processes value for that dispatcher to 0. Then, all of the processing will take
place at an available mirror location and no processing will take place on the dispatcher. You can
even set the Maximum Processes value for individual cubes.
Example 1: Dedicated Processors
In the configuration depicted below, each of four cubes has a dedicated computer on which to
process requests.
These cubes are configured with no source and a single mirror reference. On the computers that
process the cubes, each cube is configured with a source and must have sharing enabled.
Example 2: A 7 x 24 System
In the configuration depicted below, a report has three computers that can handle overflow. If the
report processor is very busy, any of the supporting computers can pick up the request, relieving
the first computer from having to queue reports. This effectively triples the number of available
processes for the report without requiring you to increase the Maximum Processes limit to a level
that the first computer may not be able to handle. This configuration is also useful in a 7 x 24
system that offers redundancy to minimize any single point of failure.
The report is configured with a source on the same computer and three mirror references.
30 Cognos PowerPlay (R)