Hi, My cluster turned red due to dangling indexes.
i saw below warning message on the coordinating nodes. none of the nodes were restarted during this time. all the nodes in cluster were up and running from 20 days and this issue happened today.
can not be imported as a dangling index, as an index with the same name and UUID exist in the index tombstones. This situation is likely caused by copying over the data directory for an index that was previously deleted.