retry_delay
Seconds to wait between retry attempts after a failed connect.
retry_delay: float = 1.5
An exponential backoff multiplier is applied on each subsequent retry, so the actual delay doubles each time: 1.5, 3.0, 6.0, and so on. Set to 0 to disable the delay entirely (useful in tests).
Notes
The maximum effective delay is capped at timeout; if the cumulative delay would exceed the timeout, the pool gives up immediately instead of sleeping.