gRPC 4 DEADLINE_EXCEEDED vs 16 UNAUTHENTICATED
Both gRPC 4 (DEADLINE_EXCEEDED) and 16 (UNAUTHENTICATED) belong to the gRPC Status Codes category. 4 indicates that the deadline expired before the operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully. Meanwhile, 16 means that the request does not have valid authentication credentials for the operation.
Description
The deadline expired before the operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully.
When You See It
The RPC took longer than the configured deadline allows. Common in slow network conditions, overloaded servers, or when the deadline is set too aggressively.
How to Fix
Increase the client deadline, optimize the server-side processing, or add server-side caching. If the operation might have succeeded, check idempotency before retrying.
Description
The request does not have valid authentication credentials for the operation.
When You See It
No credentials were provided, or the provided token/certificate is expired or invalid. Different from PERMISSION_DENIED (code 7), which means authenticated but not authorized.
How to Fix
Provide valid authentication credentials (e.g., refresh the OAuth token, regenerate the API key, or renew the client certificate).
Key Differences
gRPC 4: The deadline expired before the operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully.
gRPC 16: The request does not have valid authentication credentials for the operation.
You encounter 4 when the RPC took longer than the configured deadline allows. Common in slow network conditions, overloaded servers, or when the deadline is set too aggressively.
You encounter 16 when no credentials were provided, or the provided token/certificate is expired or invalid. Different from PERMISSION_DENIED (code 7), which means authenticated but not authorized.
When to Use Which
For 4 (DEADLINE_EXCEEDED): Increase the client deadline, optimize the server-side processing, or add server-side caching. If the operation might have succeeded, check idempotency before retrying. For 16 (UNAUTHENTICATED): Provide valid authentication credentials (e.g., refresh the OAuth token, regenerate the API key, or renew the client certificate).