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<mailto:nick.dun...@vecima.com> [cidimage001.png@01D6CC8C.6FC5A580]
