[IGNITE-13189] Maintenance mode switch and defragmentation process initialization

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Assignee: Sergey Chugunov
• Reporter: Sergey Chugunov
• Created: 26/Jun/20 14:04
• Updated: 17/Nov/20 14:20
• Resolved: 17/Nov/20 14:20

Description

As described in IEP-47 defragmentation is performed when a node enters a special mode called maintenance mode.

Discussion on dev-list clarifies algorithm to enter maintenance mode:

1. Special key is written to local metastorage.
2. Node is restarted.
3. Node observes the key on startup and enters maintenance mode.

Node should be fully-functioning in that mode but should not join the rest of the cluster and participate in any regular activity like handling cache operations.