As the number of users on the system increases, a single subsystem
for a set of work is often insufficient. By dividing your users into multiple
subsystems you gain several advantages.
- Improved manageability of work
- You get better control over what work is running in each subsystem. For
example, for server jobs, you might want to isolate all of the database server
jobs to one subsystem, the remote command server jobs to a different subsystem,
the DDM server jobs to yet a different subsystem and so on. Additionally,
by using multiple subsystems you can isolate groups of jobs with their own
memory pools. In this way, one group does not adversely impact other jobs.
- Reduced downtime impact for users
- For example, if every Friday afternoon you must bring the system to the
restricted state for backup purposes, you can gradually take users offline
by ending one subsystem at a time.
- Improved scalability and availability
- By having a single subsystem do work for fewer users, the subsystem is
less busy and can be more responsive to the work requests it handles.
- Improved error tolerance in interactive subsystems
- By spreading the work across multiple subsystems, should a network failure
occur, multiple subsystems can manage the device recovery processing.
- Improved interactive subsystem startup time
- You can keep the subsystem startup times shorter by subdividing the work
across multiple subsystems.
- Additional options for performance tuning
- By using multiple subsystems you can set up the subsystems with a small
number of routing entries.