@saturnism @googlecloud @grpcio gRPC Microservices 201 for Java Developers Ray Tsang (@saturnism), Google Cloud Platform

@saturnism @googlecloud @grpcio Ray Tsang Developer Advocate Google Cloud Platform @saturnism | +RayTsang

@saturnism @googlecloud @grpcio BigQuery Big Data Pub/Sub Dataflow Dataproc Datalab Compute Compute Engine App Engine Container Engine Storage Cloud Storage Cloud SQL Cloud Datastore Bigtable Machine Learning Speech API Machine Learning Translate API Vision API cloud.google.com

@saturnism @googlecloud @grpcio A B C D gRPC

@saturnism @googlecloud @grpcio Microservices Concerns Concern What you can use, e.g. Load Balancing https://github.com/grpc/grpc/blob/master/doc/load-balancing.md Server-side: Lyft Envoy, NGinx, or Client-side: With Central Registry Service Registry (Client Side LB) Consul, Zookeper, Eureka, gRPC LB Health Checking https://github.com/grpc/grpc/blob/master/doc/health-checking.md gRPC Health Check Protocol Or, Expose endpoints Security TLS, Token headers Authorization Token headers Distributed Tracing Zipkin Monitoring Prometheus

@saturnism @googlecloud @grpcio Microservices Concerns Concern What you can use, e.g. Load Balancing https://github.com/grpc/grpc/blob/master/doc/load-balancing.md Server-side: Lyft Envoy, NGinx, or Client-side: With Central Registry Service Registry (Client Side LB) Consul, Zookeeper, Eureka, gRPC LB Health Checking https://github.com/grpc/grpc/blob/master/doc/health-checking.md gRPC Health Check Protocol Or, Expose endpoints Security TLS, Token headers Authorization Tokens, JWT, OAuth Distributed Tracing Zipkin Monitoring Prometheus

@saturnism @googlecloud @grpcio It was pretty easy w/ HTTP/1 Used HTTP Headers What do we do in gRPC?!

@saturnism @googlecloud @grpcio Header Greeting Service Client greeting(HelloRequest) POST /…./GreetingService Client-ID: GreetingClientV1 … [HelloRequest payload] Client-ID: GreetingClientV1

@saturnism @googlecloud @grpcio Metadata! Greeting Service Client greeting(HelloRequest) Type-safe construct for attaching Header/Trailer to the requests Metadata metadata = new Metadata(); metadat.put(key, value); stub = MetadataUtils.attach(stub, metadata); stub.greeting(request); Client-ID: GreetingClientV1 Metadata: { Client-ID: GreetingClientV1 }

@saturnism @googlecloud @grpcio Getting the Metadata Greeting Service Client greeting(HelloRequest) On the server side, intercept the call to get the metadata. Client-ID: GreetingClientV1 Metadata: { Client-ID: GreetingClientV1 } Metadata: { Client-ID: GreetingClientV1 }

@saturnism @googlecloud @grpcio How to access? Context! Greeting Service Client greeting(HelloRequest) Client-ID: GreetingClientV1 Metadata: { Client-ID: GreetingClientV1 } Metadata: { Client-ID: GreetingClientV1 } Context Client-ID: GreetingClientV1

@saturnism @googlecloud @grpcio So what is Context again? Carries scoped values across API call / threads in the same process But NOT across the wire!

@saturnism @googlecloud @grpcio Propagate - MD → Ctx → MD Greeting Service Client Context Client-ID: GreetingClientV1 Client 2 Metadata: { Client-ID: GreetingClientV1 } Translation Service Client-ID: GreetingClientV1

@saturnism @googlecloud @grpcio Use Client Interceptor Greeting Service Client Context Client-ID: GreetingClientV1 Client 2 Metadata: { Client-ID: GreetingClientV1 } Translation Service Client-ID: GreetingClientV1

@saturnism @googlecloud @grpcio Answer to everything Metadata → Context → Metadata Auth Token Deadline Distributed Trace ID

16 Let's see it...

17 grpc is Open Source We want your help! http://grpc.io/contribute https://github.com/grpc irc.freenode.net #grpc @grpcio [email protected]

Google Cloud Platform 18 @saturnism @googlecloud @grpcio https://github.com/saturnism/grpc-java-demos Thanks!