Unfreezes an index.
POST /<index>/_unfreeze
When a frozen index is unfrozen, the index goes through the normal recovery process and becomes writeable again. See Frozen indices and Freeze index.
index
(required)
The following example freezes and unfreezes an index:
POST /my_index/_freeze POST /my_index/_unfreeze
Freezing an index will close the index and reopen it within the same API call. This causes primaries to not be allocated for a short amount of time and causes the cluster to go red until the primaries are allocated again. This limitation might be removed in the future.