[Mauiusers] scheduling with standing reservations

Marcin mar_mog at o2.pl
Mon Apr 3 06:13:15 MDT 2006


I configured maui to divide nodes in two pools using standing 
reservations some time ago and, I admit, It works. My definitions look 
this way:

SRCFG[batch] PERIOD=INFINITY HOSTLIST=n[1-9]$,n[1-9][012345]$ 
SRCFG[v40z] PERIOD=INFINITY HOSTLIST=n10[123456789]$,n11[012]$ 

So I have three not overlapping reservations. Every job which fits into 
one of this reservations wont't fit in any other of them. It works. But 
scheduling, ehm, works quite illogical.

In short - only the highest priority job is ever started, jobs with 
lesser priority waiting in the queue won't start even when there are 
free resources in the reservation they fit in and the highest priority 
job, waiting to be started, won't. Simply from logical point of view I 
have two pools of nodes, but I can't force maui to stop treating them as 
one big pool.


54810         user2       Idle    16  2:00:00:00  Mon Apr  3 10:56:04
54793         user2       Idle     8    12:00:00  Mon Apr  3 10:57:13

Job 54810 has higher priority than 54793 and should be started first. 
Job 54810 fits into batch reservation, job 54793 fits into v40z 
reservation. There are enough free resources in v40z reservation to 
start job 54793. Job 54810 has to wait for free resources. Conclusion - 
job 54793 can, and should, be started at once. The way it works - lesser 
priority job will never start before higher priority one. I can see 
shown situation every several hours.

Anyone knows how to overcome this issue? It's quite fustrating to 
correct scheduler by hand every several hours...

There are two more 'issues' (well, bugs). First - when maui is started 
it sets reservations on online nodes only. It means that if node is 
down, maui is started and node is up later, it will have na reservations 
at all. Second - CLASSCFG parameter in SRCFG declaration doesn't work - 
being in class allowed to use reservation makes maui to return that job 
is not allowed to use that reservation while in fact it should allow it.

	Marcin Mogielnicki

More information about the mauiusers mailing list