Max concurrent checks - spreading the next_time

[Hiren Patel]

Andreas Ericsson wrote:
> The randomization thing will almost certainly make sure that doesn't happen.
> To be 100% certain it doesn't happen, one has to inspect the elements queued
> for running and make a weighting of them to see how long ago something was
> actually checked before making the decision on what to check.
> 
> Or one could simply iterate linearly over the event-list, which would cause
> latency to increase slowly if max_concurrent_checks is set too low, but would
> ensure that checks are run in the order they are scheduled. In order to make
> sure checks are run in the approximate time they're scheduled to run, this is
> probably the best bet. I'll need to investigate that though and I'm sorely
> short on time now both due to Merlin/Ninja and due to recreational activities
> taking place during the summer.
> 
> Any other takers on this? The questions that need answering are:
> 1. How does this affect the high/low prio list?
> 2. How much does latency increase (latency has to be re-calculated for each
>    re-scheduled check as well as for all checks that happen off-time).
> 3. How does it affect the load on the system? Are we currently spending too
>    much time re-scheduling checks so we'd actually gain "checks-per-second"
>    performance by just iterating linearly over the list?
> 
> Once we know the above, writing the code will probably be quite trivial.
> 
would I be correct in assuming that either way, average latency is going 
to raise. in this case, should we not notify an admin or display a 
warning somewhere in cgi to inform a nagios administrator that checks 
are not running on schedule. perhaps an avg_latency_notify setting? if 
such an alert is not already being sent, it might be better for the 
admin to find out this way than having some service fail with no 
notification only to find out that the checks aren't running on schedule?


------------------------------------------------------------------------------
Crystal Reports - New Free Runtime and 30 Day Trial
Check out the new simplified licensing option that enables unlimited
royalty-free distribution of the report engine for externally facing 
server and web deployment.
http://p.sf.net/sfu/businessobjects