Handling errors and error status codes
Unlike REST, which makes use of the HTTP status codes, gRPC uses a Status model, which contains its error codes and optional error message (string).
If you remember, you have used the special class called Error to contain the error details because HTTP error codes contain limited information. Similarly, the gRPC error Status model is limited to code and an optional message (string). You don't have sufficient error details for the client to use to handle the error or retry. You can make use of the richer error model as described at https://cloud.google.com/apis/design/errors#error_model, which allows you to pass detailed error information back to the client. You can also find the error models in the next code block for quick reference:
package google.rpc;message Status {
// actual error code is defined by `google.rpc.Code`.
int32 code = 1;
// A developer-facing human-readable error message
&...