Chapter 11 – gRPC-Based API Development and Testing

1. Because, unlike HTTP libraries, gRPC libraries also provide the following features:

   a. Interaction with flow control at the application layer

   b. Cascading call cancellation

   c. Load balancing and failover

2. Yes, we can. You can use the metadata as shown in the next code block. However, making use of com.google.rpc.Status allows you to use the details (with a type of Any) object, which can capture more information:

   Metadata.Key<SourceId.Response> key =
       ProtoUtils.keyForProto(SourceId.Response.getDefaultInstance);
    
   Metadata metadata = new Metadata();
   metadata.put(key, sourceIdResponse);
   respObserver.onError(Status.INVALID_ARGUMENT
      .withDescription("Invalid Source ID")
      .asRuntimeException(metadata));

3. com.google.rpc.Status can include details of type Any, which can be used to provide more error details. io.grpc.Status does not have a field that...