Concurrent segment search in Amazon OpenSearch Service

Starting with OpenSearch version 2.13, you can use concurrent segment search to help you search segments in parallel during the query phase. For full documentation of concurrent segment search, see Concurrent segment search in the open source OpenSearch documentation. For information about Amazon CloudWatch metrics related to concurrent segment search, see Instance metrics and UltraWarm metrics.

There are a few additional limitations that apply when you use current segment search with Amazon OpenSearch Service:

• You can't enable concurrent segment search at an index level in OpenSearch Service.

• By default, OpenSearch Service uses a count of 2 slices with the max slice count mechanism.