- each proxy stores average RTT (round trip time) of last rttCount queries.
For now, I assigned the value 4 to rttCount
- the read timeout is calculated as doubled average RTT, but it cannot
exceed default timeout
- initial avg RTT is set to a half of default timeout, so initial timeout
is equal to default timeout
- the RTT for failed read is considered equal to default timeout, so any
failed read will lead to increasing average RTT (up to default timeout)
- dynamic timeouts will let us react faster on lost UDP packets
- in future, we may develop a low-latency forward policy based on
collected RTT values of proxies
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