An assign arriving before any volume server has heartbeated saw zero
available space and failed outright with a plain error no client retries,
so the first write to a fresh bucket answered 500 while the cluster was
still starting. Distinguish a topology with no registered capacity from a
genuinely full one: fail fast only when registered capacity is exhausted,
and shed ResourceExhausted otherwise so the client's retry budget rides
out the startup window.
Claude-Session: https://claude.ai/code/session_018G9kWFgy8BaBAEkYV3YL9n
Chris Lu
d3b8030a69