I haven’t looked at parent proxy setup much, but at a high level, I can’t think of any reason why an origin failover mechanism would impact request coalescing using collapsed forwarding plugin. The open write fail action works based on the cache key for the object and as long as that doesn’t change, it shouldn’t matter which origin it is pulled from. As a matter of fact, we have had origin failover setup using a custom plugin as well as request coalescing enabled in our HLS delivery servers and didn’t see any problems with it.
Is it possible the access failures are resulting in preventing the object from being downloaded or being cached somehow? If the object is never cached, then you will see problems with request coalescing. Thanks, Sudheer > On Mar 8, 2018, at 7:25 AM, Dunkin, Nick <[email protected]> wrote: > > Hi, > > We’ve been using the Thundering Herd protection provided by Read While > Writer, Open Read Retry Timeout and Open Write Fail Action and have been > getting some great results. However the behavior seems to change when we > start using parent.config in order to provide some simple origin failover > (I.e simple Primary/Secondary Origin kind of thing). My initial tests are > showing multiple access failures and not very much in the way of request > coalescing. > > I don’t all have the details with me now, but at a high level, should we > expect Read While Writer, Open Read Retry Timeout and Open Write Fail Action > to all work in the same way when > proxy.config.http.parent_proxy_routing_enable is enabled and we have a simple > Primary/Secondary Origin configured with "parent_is_proxy=false”? Especially > when most of the time the Primary Origin will be up and available. Are there > any gotchas we should be aware of? > > All this testing is with ATS 7.0 currently. > > Thanks for your insight. > > Nick > > Nick Dunkin > Principal Engineer > o: 678.258.4071 > e: [email protected] > 4375 River Green Pkwy # 100, Duluth, GA 30096, USA > > <319E5E02-1647-4542-836C-D389403ADE5F.png>
