| gRPC Wait for Ready Semantics |
| ============================= |
| |
| If an RPC is issued but the channel is in `TRANSIENT_FAILURE` or `SHUTDOWN` |
| states, the RPC is unable to be transmited promptly. By default, gRPC |
| implementations SHOULD fail such RPCs immediately. This is known as "fail fast," |
| but usage of the term is historical. RPCs SHOULD NOT fail as a result of the |
| channel being in other states (`CONNECTING`, `READY`, or `IDLE`). |
| |
| gRPC implementations MAY provide a per-RPC option to not fail RPCs as a result |
| of the channel being in `TRANSIENT_FAILURE` state. Instead, the implementation |
| queues the RPCs until the channel is `READY`. This is known as "wait for ready." |
| The RPCs SHOULD still fail before `READY` if there are unrelated reasons, such |
| as the channel is `SHUTDOWN` or the RPC's deadline is reached. |
