[ACCUMULO-4353] Stabilize tablet assignment during transient failure

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.8.0
• Assignee: Shawn Walker
• Reporter: Shawn Walker
• Created: 23/Jun/16 19:19
• Updated: 02/Aug/16 23:00
• Resolved: 02/Aug/16 23:00

Description

When a tablet server dies, Accumulo attempts to reassign the tablets it was hosting as quickly as possible to maintain availability. If multiple tablet servers die in quick succession, such as from a rolling restart of the Accumulo cluster or a network partition, this behavior can cause a storm of reassignment and rebalancing, placing significant load on the master.

To avert such load, Accumulo should be capable of maintaining a steady tablet assignment state in the face of transient tablet server loss. Instead of reassigning tablets as quickly as possible, Accumulo should be await the return of a temporarily downed tablet server (for some configurable duration) before assigning its tablets to other tablet servers.

Issue Links

• breaks: ACCUMULO-4381 Use of JDK8 Process.isAlive() method in SuspendedTabletsIT
• links to: GitHub Pull Request #121