Replica Shard 也能提升aggregation的效率吗？

Elastic In Your Native Tongue 中文提问与讨论
1

Hi

I know Replica Shard can help to improve search. But how about aggregation? Aggregation is based on field data or Doc Value. So I`m not sure if the replica shard (which is inverted index) will help aggregation also?

Regards
Mingwei

2

Hi,
The answer is yes, more replicas can improve the search and also the aggregation, not the single request, but improve the throughout.

Medcl

3

Thanks very much.
But I do not understand this part. "Not the single request but improve the throughout", Can you help to explain please?

Also, is there any doc or articles talking about this ?
I can only find that the official docs says very clearly that replica improve search speed. Did not find anything about replica and AGG.

4

AGG only run within one shard group, for a single AGG query, it will only utilize one shard group, no matter primary shard or replica shards, they are acted as the same way, just like the search works, but more replicas means more resource can be used, so you can improve the search or AGG query throughout by having more replica (hardware resource provided as well), make sense?