Increase in `Namespace#pages_virtual_domain` method call wall time
Description
During my investigation of how many request-per-sec our pages node cumulatively make to retrieve information about domain, I discovered that during the 40% -> 70% rollout we saw a huge spike in pages_virtual_domain
wall clock time.
It is possible this is basically an expensive method and the operation of warming the cache for additional 30% of domain being used caused that. Presumably this could get back to normal after some time after the cache gets populated, but it still might be a good idea to investigate this.
Rollout time for comparision:
/cc @krasio @vshushlin
Edited by Grzegorz Bizon