NetBatch Manual

Scheduler Planning, Configuration, and
Management
NetBatch Manual—522460-004
3-7
Task 3. Establish Class and Executor Configurations
Executor Numbers
The number of executors you plan depends on the number of CPUs on the scheduler’s
node and on your jobs’ CPU and I/O resource requirements. HP recommends four
executors per CPU:
•
One executor for classes that group jobs by function or purpose.
•
One executor for classes whose jobs are CPU-bound.
•
Two executors for classes whose jobs are I/O-bound. You can have more
executors
for these classes, depending on your CPUs’ power and the number of
logical devices configured for them. For example, an eight-disk-per-CPU NonStop
Cyclone system can handle more executors than a two-disk-per-CPU NonStop
CLX system.
An exception to the four-executors-per-CPU rule applies when you want to run more
concurrent jobs than there are executors. Because the number of started executors
determines how many jobs can run concurrently (one job per executor), you might
need extra executors. For example, to run 20 concurrent jobs in a scheduler with 16
executors (all started), you would need another four started executors.
CPU Assignment
Consider existing loads on CPUs before assigning executors to those CPUs. For
example, a CPU might be running a critical online Pathway application. Increasing that
CPU’s workload by directing jobs to it through executors might affect the application’s
performance. In these circumstances, consider assigning only one executor to the
CPU or perhaps none.
Class Assignment
As a general rule, assign classes whose jobs have similar characteristics to executors
catering to jobs with those characteristics. For example, assign classes containing
CPU-bound jobs to executors dedicated to processing CPU-bound jobs. Similarly,
assign classes for I/O-bound jobs to executors processing I/O-bound jobs, and so on.
Assigning a class to more than one executor helps avoid a job backlog in that class.
The order in which you assign classes to executors is also important. Jobs in the first
class assigned to an executor take priority over jobs in the second class, jobs in the
second class have priority over those in the third class, and so on. Varying the order in
which you assign classes to executors ensures jobs in those classes have similar
processing opportunities.
Executor-Naming Conventions
As with class names, consider naming conventions when planning your schedulers’
executors. Some commands let you specify multiple executors with wild-card
characters, so use names you can mask easily with those characters.