Rntbd Connection - Health Check Improvements

[kundadebdatta]

This task proposes adding more aggressive timeout check in the Rntbd connection health check.

The current flow:

• Per connection, if there are 3 consecutive request timeout within 65s, then connection will be closed.

Improvements proposed:

• If the last request time is 65 seconds ago or any threshold configured, close on first timeout
• On primary replicas, close connections more aggressively (first timeout + 5.5s/6s/configured threshold) or Math.max (3 times request timeout, 6 seconds)
• These aggressive closure should be a opt-in behavior for now