mirror of
https://github.com/honeymoose/OpenSearch.git
synced 2025-02-17 10:25:15 +00:00
51fe20e0c3
With the upcoming cross-cluster search alternate execution mode, the CCS node will be able to split a CCS request into multiple search requests, one per remote cluster involved. In order to do that, the CCS node has to be able to signal to each remote cluster that such sub-requests are part of a CCS request. Each cluster does not know about the other clusters involved, and does not know either what alias it is given in the CCS node, hence the CCS coordinating node needs to be able to provide the alias as part of the search request so that it is used as index prefix in the returned search hits. The cluster alias is a notion that's already supported in the search shards iterator and search shard target, but it is currently used in CCS as both index prefix and connection lookup key when fanning out to all the shards. With CCS alternate execution mode the provided cluster alias needs to be used only as index prefix, as shards are local to each cluster hence no cluster alias should be used for connection lookups. The local cluster alias can be set to the SearchRequest at the transport layer only, and its constructor/getter methods are package private. Relates to #32125