gRPC 0 OK vs 9 FAILED_PRECONDITION
Both gRPC 0 (OK) and 9 (FAILED_PRECONDITION) belong to the gRPC Status Codes category. 0 indicates that the operation completed successfully. Not an error; returned on success. Meanwhile, 9 means that the operation was rejected because the system is not in a state required for the operation's execution. For example, deleting a non-empty directory.
説明
The operation completed successfully. Not an error; returned on success.
このコードが表示される場合
The RPC completed without any issues. This is the expected response for every successful gRPC call.
解決方法
No fix needed — this indicates everything worked correctly.
説明
The operation was rejected because the system is not in a state required for the operation's execution. For example, deleting a non-empty directory.
このコードが表示される場合
The request is valid on its own, but the system's current state doesn't allow it — like trying to delete a non-empty directory or update a resource that has been modified concurrently.
解決方法
Bring the system into the required state before retrying. For example, empty the directory first, or re-read the resource to get the latest version before updating.
主な違い
gRPC 0: The operation completed successfully. Not an error; returned on success.
gRPC 9: The operation was rejected because the system is not in a state required for the operation's execution. For example, deleting a non-empty directory.
You encounter 0 when the RPC completed without any issues. This is the expected response for every successful gRPC call.
You encounter 9 when the request is valid on its own, but the system's current state doesn't allow it — like trying to delete a non-empty directory or update a resource that has been modified concurrently.
どちらをいつ使うか
For 0 (OK): No fix needed — this indicates everything worked correctly. For 9 (FAILED_PRECONDITION): Bring the system into the required state before retrying. For example, empty the directory first, or re-read the resource to get the latest version before updating.