Issue #3362 has been updated by Mark Plaksin.

Can we have an option to disable this change?  We have adapted to how splay
currently works and our client checkins are almost perfectly spread out.
We have 400+ clients and have 15-20 checkins each minute.  Last time splay
changed we spent a lot of time re-adjusting to spread out the load.

This change might be awesome and work perfectly for us (and everybody else)
but it might have unanticipated consequences so a switch to leave things as
they were before the change would be great.
----------------------------------------
Bug #3362: splay drift occurs when passenger/mongrel get too much load.
http://projects.reductivelabs.com/issues/3362

Author: Dan Bode
Status: Investigating
Priority: Normal
Assigned to: 
Category: plumbing
Target version: Statler
Affected version: 0.25.4
Keywords: passenger load splay mongrel connection timeouts
Branch: http://github.com/MarkusQ/puppet/tree/ticket/0.25.x/3362


not sure if this counts as a bug...

I could not concretely prove the assumptions below. I did some investigation 
and this is my best guess as to the cause.

Splay was drifting for hundreds of machines so that over time, most were 
checking in at the same time, while at other times none were checking in. here 
is my theory as to why.

splay only runs the first time after puppet starts.

Assumption: runinterval starts counting only after the client finishes its last 
run?

Here is the chain of events that I think causes this:

1. passenger or mongrel is under heavy load.
2. processes get used up, they start queuing hosts.
3. Once a machine falls into the queue, it gets stuck with the group of 
machines that cause the queue to fill up, since it will now use runinterval and 
check in at the same time as the other machines that were running at that same 
time.
4. Over time, splay drifts so that most machines are checking in at the same 
time.

Basically, once performance starts getting bad, the splaying falls apart so 
that it gets much worse.




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