Simple equal user sharetree policy

Posted by chris Tue, 17 Jan 2006 22:33:30 GMT

The easiest way to set up Grid Engine for fair "all users treated equally" resource allocation is the simple functional policy setup described in a previous entry.

But what about doing something similar with the ShareTree policy? (a basic graphical explanation of the differences between the functional and sharetree policies can be found here).

It is also a two step process:

  1. Activate the policy in the scheduler configuration (command is 'qconf -msconf') 
    • weight_tickets_share 100000
  2. Create a simple share tree with a special default leaf node ('qconf -mstree'), pasting in the following should be sufficient: 
    • id=0
name=Root
type=0
shares=1
childnodes=1
id=1
name=default
type=0
shares=1
childnodes=NONE

Additional things to consider include ...

The default halftime configured is one week. Despite the SGE documentation suggesting that unqualified integer values used in time fields represent seconds, the pre-configured default value for the scheduler parameter 'halftime' seem to be set in increments of hours. This means the default value of 168 sets a halftime of one-week in length. Consider setting halftime to "24" or "48" if you want the scheduler to only factor in usage over the past day or two when doing policy based scheduling calculations.

Also consider the following blog post by Stephan:
http://blogs.sun.com/roller/page/sgrell?entry=a_couple_lines_on_halftime

Some users may wish to consider altering the value of "usage_weight_list" to disable use of memory and IO statistics when performing share tree calculations. Some organizations may find it easier to explain to end users that the share tree allocation policy is making decisions purely on how much CPU time was consumed in prior tasks.