Bug 639358 - GROUP_DYNAMIC_MACH_CONSTRAINT undocumented feature
Summary: GROUP_DYNAMIC_MACH_CONSTRAINT undocumented feature
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise MRG
Classification: Red Hat
Component: Grid_User_Guide
Version: beta
Hardware: All
OS: Linux
low
medium
Target Milestone: 2.1
: ---
Assignee: Alison Young
QA Contact: Tomas Rusnak
URL:
Whiteboard:
: 634744 (view as bug list)
Depends On: 652506 733205
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-10-01 14:32 UTC by Tomas Rusnak
Modified: 2012-01-26 19:17 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Enhancement
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-01-26 19:17:01 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)

Description Tomas Rusnak 2010-10-01 14:32:40 UTC
Description of problem:
In the current documentation the GROUP_DYNAMIC_MACH_CONSTRAINT is not documented.

How reproducible:
always

Expected results:
parameter documented

Documentation draft:
GROUP_DYNAMIC_MACH_CONSTRAINT assists the Negotiator in converting dynamic
group quotas, %'s, in absolute numbers. If you have a pool of 1000 slots and
two groups each with 0.5 dynamic quota (50%), the negotiator will assume it can
give 500 matches to each group. If in fact 998 of those slots are in Owner
state, there are only 2 slots and the split should be 1 each.
GROUP_DYNAMIC_MACH_CONSTRAINT provides a way to trim the absolute number of
assumed matchable slots to make the absolute quotas more realistic.

It should probably default to State != "Owner" && Cpus > 0

Comment 1 Lana Brindley 2010-10-05 04:44:03 UTC
*** Bug 634744 has been marked as a duplicate of this bug. ***

Comment 2 Lana Brindley 2010-10-05 04:45:21 UTC
From BZ#634744:

Erik Erlandson 2010-09-27 12:58:29 EDT
When the Hierarchical Fair Share (HFS) algorithm computes the number of slots
it will give to each accounting group, it may include slots that cannot accept
any matches during the subsequent negotiation.   This may cause the first
groups that negotiate to receive a disproportionate number of the actual
matchable slots, and subvert the intention of HFS.

The condor administrator may choose to mitigate this behavior by setting the
GROUP_DYNAMIC_MACH_CONSTRAINT configuration parameter.  
GROUP_DYNAMIC_MACH_CONSTRAINT stores a boolean expression which is evaluated
for each candidate slot.  Slots for which this expression evaluates to True are
considered by HFS.

For example, one useful setting to focus HFS on matchable slots would be:

GROUP_DYNAMIC_MACH_CONSTRAINT = (State != "Owner") && (Cpus > 0)

This setting causes HFS to consider slots on machines which are currently
unused, and which have CPUs to allocate.

Another example is:

GROUP_DYNAMIC_MACH_CONSTRAINT = (State == "Unclaimed")

Which causes HFS to consider only unclaimed slots.

Comment 4 Alison Young 2011-02-15 05:40:18 UTC
Pushing to 2.1 due to time and resource constraints.

Comment 8 Tomas Rusnak 2011-11-14 12:15:06 UTC
Documentation changes confirmed on the bottom of 10.3. Hierarchical Fair Share (HFS) chapter.

Revision 1-20	Thu Nov 03 2011	Alison Young
BZ#639358 - GROUP_DYNAMIC_MACH_CONSTRAINT undocumented feature

Revision info included.

>>> VERIFIED

Comment 9 Lana Brindley 2012-01-26 19:17:01 UTC
This book is now available on redhat.com/docs. Please raise a new bug if you spot any issues.

Thanks,
LKB


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