Yes, max_simple retries should be no more than the total number of parents -1.
Let’s say that you have 5 parents and all 5 send back a 404, that’s what it should be if none of the parents has the object. However, if you set max_simple_retries greater than the total number of parents, the final response would be a 502 because all parents were tried and no other parents are available. So if you have a total of 5 parents, set max_simple_retries to 4, Number of parents - 1 John > On Sep 15, 2022, at 1:23 PM, Nick Dunkin <nick.dun...@vecima.com.INVALID> > wrote: > > Hi John, > > Thanks for the clarification. > > My short term mitigation is going to require me to increase the value of > max_simple_retries. This property is currently fixed in the code to a > maximum values of 5. Are you aware of any reason that I can’t safely > increase that maximum (in the code) to something like 8? My 404 responses > are expected to be very quick, so I’m not too concerned about the cumulative > timing implications that would occur in this rare failover use case. > > Is there anything special about the upper bound value of 5 for this > max_simple_retries property? > > Thanks > > Nick > > From: John Rushford <jjrushf...@gmail.com> > Date: Thursday, September 15, 2022 at 2:53 PM > To: dev@trafficserver.apache.org <dev@trafficserver.apache.org> > Subject: Re: Different parent rules for 404 vs 5xx or unavailable > Nick, > > Currently this is not supported a change would have to be made to support it. > > John Rushford > jrushf...@apache.org > > Sent from my iPhone > >> On Sep 15, 2022, at 10:14 AM, Nick Dunkin <nick.dun...@vecima.com.invalid> >> wrote: >> >> >> Hi, >> >> I have a parent.config rule that uses a primary and secondary set of parents. >> >> Assuming a 404 from a parent in the primary list I would like to immediately >> try a parent in the secondary parent list, but for a 5xx, or connection >> error, I would like to first exhaust the primary list first, before then >> trying the secondary. >> >> I would imagine this is a fairly common use case for cluster failover >> behavior. i.e. “Content is HTTP 404 form cluster A, so go to cluster B” >> >> I am not able to get this use case working with the various options for >> secondary_mode in parent.config (ATS ver 9.1.3). >> >> Please can anyone provide assistance? Maybe this use case is supported with >> strategies.yaml? >> >> Thanks >> >> Nick >> >> Nick Dunkin >> Director, Software Architecture >> Manager – Architecture and New Product Introduction >> o: +1 678.258.4071 >> e: nick.dun...@vecima.com >> >> >>
