[KUDU-2176] Pipeline leader writes to followers

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: consensus
• Labels: roadmap-candidate scalability
• Assignee: Unassigned
• Reporter: Mike Percy
• Created: 06/Oct/17 17:13
• Updated: 02/Jun/20 20:48

Description

We may improve write latency and throughput by allowing multiple messages to be in-flight from a Raft leader to its followers. Secondarily, it may also help with MTTR (for re-replication) because after tablet copy a node has to catch up via normal streaming means.

Note that pipelining writes could exacerbate the RPC “stacking problem” that we already have under certain conditions.