Multi threaded gRPC server and data order

[Rocha Stratovan]

Hello,

I am working with a gRPC server implementation that receives a streamed binary file.

I understand that the gRPC server is multi-threaded and so the "receive" callback can be invoked by by multiple threads at the same time.

How is order maintained in this scenario? I thought I saw that gRPC also guarantees order, implying that the 3rd gRPC message in a stream won't be processed before the 2nd or 1st.

Thank you,

John Rocha

[Kannan Jayaprakasam]

Saying gRPC server is multi-threaded is a vague statement. At the transport level all messages from a stream are handled by the same transport thread. When dispatching deframed messages from a stream to the application, gRPC dispatches messages to the StreamObserver implemented by the application via the call executor (that can be supplied to the Grpc server builder). It is here that different messages could be handled by different threads in the call executor. The code supplied to the call executor however is a wrapper code that calls the StreamObserver in a serialized manner by serializing them in the call's Context. This makes sure that different messages from the same stream are still handled in the received order. 

Note: The above answer elucidates using Java but the idea will be similar in other languages.

--
You received this message because you are subscribed to the Google Groups "grpc.io" group.
To unsubscribe from this group and stop receiving emails from it, send an email to grpc-io+u...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/grpc-io/24a2a141-1700-4df9-bd23-72a866b73872n%40googlegroups.com.