More efficient zone usage

[garycourt]

When a node needs to get data from another shard (such as during a get or view), it should choose a shard/node that is within the same zone as the current node (if up/available) before choosing a node that is outside of it's zone.

Currently, zones are only used to determine where shard copies are distributed; views are spread across all zones.

[kocolosk]

Hi @garycourt, I definitely see the need for a zone-aware selection of shards during stale=ok views, where BigCouch only selects one copy of each database shard. When it comes to normal document and view requests BigCouch asks for results from all copies of a shard and discards slower responses. What's the rationale for avoiding non-local zones in that case?

[garycourt]

While I had gets and stale views in mind, you're right to state that it would not be appropriate for normal views.