[RFC] Search only shards in the scale down state do not pull data from the remote store #21069
Description
Is your feature request related to a problem? Please describe
Under the current read-write separation architecture, search only shards use the AsyncReplicationTask to sync segment data from remote storage. Even after a scale down operation has been performed, search only shards will still periodically pull metadata from remote storage.
Describe the solution you'd like
To avoid redundant operations of pulling metadata from the remote store, we can decide whether to perform the pull action based on INDEX_BLOCKS_SEARCH_ONLY_SETTING.
Related component
Indexing:Replication
Describe alternatives you've considered
No response
Additional context
No response