Thanks, but I think we're getting off topic.
I know how FSS works and what its intended for, however the
issue isn't with FSS but more that the load averages as seen
within a zone are not based on the loads in the zone, but
rather to the pool to which the zone is associated with.

FSS isn't the culprit here, sorry I made it sound that way.
So if you don't enable pools (so there's one shared pool) and
you use FSS to divide up the resources, then sendmail within one
of the local zones makes decisions based on the load average of
the processor set (which is the load of all zones put together)
rather than just the workload of the zone.  So if another zone
consumes 99.9% of the CPU, the idle zone running sendmail will
reject connections because the load average has been exceeded,
even though FSS will guarantee it more CPU.


Jim Mauro wrote:

Remember that FSS is designed to provide a minimum, but not a max.
Depending on CPU use by other threads in the class, a given thread may
get more than it's alloted CPU shares, but it will never get less.

/jim


Brian Kolaci wrote:

Jeff Victor wrote:

Brian Kolaci wrote:


I've been discussing about how to chop up a machine. An possible example
configuration would have 8 cpus, 3 local zones.  They would possibly be
divided up as 50%, 25% and 25%.  Its clear how to do this with pools,
however FSS is a great fit for when a zone may need more CPU than whats
available in the pool/psrset. The problem with FSS in this case is that
if one zone is mostly idle and all the other zones are busy, the zone
that is idle will get a load average much higher than its really using
which can skew the calculations use by the sendmail process to determine
if the queue/refuse connection thresholds are met.



How does FSS make that situation worse? The misleading [1] load avg is not affected by FSS, which is merely enforcing the minimum CPU-power portions that you chose. If they are inappropriate, prctl can be your friend. :-)


[1] "misleading" for this situation, not so for others.


I guess what I mean is that with FSS, people get the impression
that they are dividing the resources fairly among the zones but the
misleading load average tells processes that they're already using
all or more than their share already.  Agreed, its not really a problem
of FSS, but that the load averages reported in a zone do not reflect
what it actually is in the zone, but of the processor set it is associated
with.
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