re: 60ms ttms take a look at the below.
https://github.com/apache/trafficserver/pull/6234 https://github.com/duke8253/trafficserver/commit/159ae2510f0e2dab0907bdf2aec1ce74da0b3653 On Wed, Mar 10, 2021 at 9:07 AM Nick Dunkin <nick.dun...@vecima.com> wrote: > Hi, > > > > I wanted to raise an interesting issue we discovered last night during > some troubleshooting. This is Traffic Server version 7.1.4. > > > > We were investigating unexpectedly long response times on cache hits. > > > > A cache miss was taking approximately *10ms* in client response time, but > subsequent cache hits, for the same content, were taking a constant, and > repeatable, *60ms* to return. > > > > After many hours of sanity checking, and configuration checking we > discovered the culprit. > > > > We are using parent routing, and our single parent rule used “ > *dest_domain=.”* > > > > If we replace the *dest_domain* wildcard rule, with a *url_regex* rule, > the issue is resolved and our cache hits become expectedly fast. > > > > So our assumption here is that the 60 ms latency is down to some DNS > related query, because we were using dest_domain, but if that’s the reason > why is parent routing even in play during a cache hit, and even a cache mem > hit? > > > > We discovered the issue on a production system, and we are going to > produce a minimal repeatable test case in the lab. When we have done that > I can post again if necessary. > > > > Can anybody help us understand what may be going on here? > > > > Many thanks, > > > > Nick > > > > *Nick Dunkin* > > Director, Software Engineering > > Manager – Architecture and New Product Introduction > > *o: * *+1 678.258.4071* > > *e:* nick.dun...@vecima.com > > > > [image: cidimage001.png@01D6CC8C.6FC5A580] >
