As an JIRA Datacenter Administrator I want to be able to cancel Full reindex

Problem Definition

There are use-cases for aborting a healthy reindexing operation:

• Accidental click on the start reindexing button.
• Cluster is under heavy load; would like to have all nodes available for servicing requests (and no extra pressure on the db from reindexing).
• CF changes while reindexing

Suggested Solution

Allowing Jira DC admins to abort a foreground reindex that's working correctly on an active node.

Workaround

• Remove the node from LB
• Shutdown the node