[HDDS-4480] Implement OM Prepare Request/Response

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Component/s: OM
• Labels: pull-request-available
• Target Version/s: 1.2.0
• Assignee: Ethan Rose
• Reporter: Ethan Rose
• Created: 17/Nov/20 20:59
• Updated: 25/Jan/21 17:14
• Resolved: 06/Dec/20 05:39

Description

Add the new OM request that will be used to prepare the OM for upgrade. In the applyTransaction step for this request:

1. Wait for double buffer flush to finish.
2. Take a snapshot.
3. purge the log.

The transaction log index of this request will be returned in the response to the caller.

Issue Links

• relates to: HDDS-4540 Add a new OM admin command to submit the OMPrepareRequest.
• links to: GitHub Pull Request #1613