In ES 2.3, is there a way to stop _optimize/_forcemerge?

Elastic Stack Elasticsearch
1

I typed in the wrong index name when I started the _optimize and I would have like to have stopped it instead of having to wait.

Is there a way to cancel them or stop them? I'm using ES 2.3 and I tried doing a _task/cancel call but it said it could not be canceled. Would closing the index stop it? What about moving the shards?

2

Only by restarting the entire cluster.