The open and close index APIs allow to close an index, and later on opening it. A closed index has almost no overhead on the cluster (except for maintaining its metadata), and is blocked for read/write operations. A closed index can be opened which will then go through the normal recovery process.
The REST endpoint is
curl -XPOST 'localhost:9200/my_index/_close' curl -XPOST 'localhost:9200/my_index/_open'