I was trying to migrate node.js application into docker containers.
When I did some API load test onto our applications which ran in docker containers, I found some API response time were beyond 10 seconds in New Relic.
By looking into the detail, I found some weird things: No matter how many times dns.lookup (external API calls) happened, the dns.lookup took 10,000ms.
I tried to do the same load test to node.js applications running directly on linux servers, I didn’t see any obvious dns.lookup latency.
I didn’t get any clue from Google search results, hope I can get some insight and help here.
Below are 4 New Relic transaction traces:
I’m not allowed to post link. So please copy&paste the string into your browser.