I ran into an interesting situation today with respect to latency due to failed DNS lookups.
THE SETUP Using RHEL8, openjdk 11, solr 9.1.1. The solr instance was standalone in a mostly out of the box config. (No SSL, only http) I had 3 entries in /etc/resolv.conf and the first one in the list was "broken". It was timing out on requests. The situation - When I would issue a query - I'd have upwards of a 5 second pause prior to completion of the request. Which feels like a timeout being hit. For example, while on the server "10.0.0.200" curl -v ' http://10.0.0.200:8983/solr/mycore/select?q=*:*&fq=locale_s:en-us&rows=1' I then edited jetty.xml to remove "org.eclipse.jetty.server.handler.InetAccessHandler" (since I wasn't using an ACL anyways). From there - results seemed to get a little better. I tended to get instant responses, but occasionally, I'd still see the multi-second delay. I'm not sure how to track down this second piece of latency when DNS fails. Is this an opportunity to also remove these lookups to improve performance? -Tim
