A retry policy: the wait grows from initial-backoff by multiplier at each failure, up to max-backoff.
initial-backoff
multiplier
max-backoff
The wait after the first failure.
The most attempts of a call in all, the first included.
The longest wait between two attempts.
How many times longer each wait is than the one before; at least 1.
How long one attempt of a handler may run before it is cancelled and counts as failed; not set, an attempt runs as long as it takes.