I'm doing Elasticsearch reindexing as a multistep process using the JavaScript client library:

• Clone index named "old" to a new index named "new"
• Delete "old" index
• Reindex from the "new" index back to "old"
• Delete the "new" index

I need to wait for the 1st step to complete before doing the next steps. Is there an Elasticsearch endpoint I can poll to find out when the clone is complete?

Tldr;

If I recall correctly, there is no specific endpoint for monitoring the clone API. But you can use the cat recovery api

Demo

POST old/_clone/new

# This call is to be made until it returns nothing
GET _cat/recovery/new?active_only=true&format=json

DELETE old