This needs to auto-magically update the pool counter limits when $wgDefaultSearchCluster !== $wmgDatacenter. This is because there is an additional 40ms round trip latency from eqiad to codfw. For full text searches this likely isn't an issue, but for shorter queries like namespace queries and prefix search we will likely need to increase the pool counter size.
Customize query in gerrit
|operations/mediawiki-config||master||+20 -0||Update CirrusSearch PoolCounter for cross-dc search|