Java netty/okhttp gRPC client throwing intermittent UNAVAILABLE: io exception while trying to connect

Question

I am trying to connect to go server with java GRPC client (netty and okhttp). But both of them are throwing UNAVAILABLE: io exception intermittently.

The occurrence is random and we don't know what's causing this behaviour. We found out that the request didn't reach the go server.

The blocking stub used to connect is something similar to:

public SomeServiceGrpc.SomeServiceBlockingStub getBlockingStub() {

        ManagedChannel channel = OkHttpChannelBuilder
                .forAddress(configuration.getHost(), configuration.getPort())
                .useTransportSecurity()
                .keepAliveTime(1, TimeUnit.MINUTES)
                .keepAliveTimeout(5, TimeUnit.SECONDS)
                .intercept(deadlineInterceptor)
                .build();
        return SomeServiceGrpc.newBlockingStub(channel);
    }

These are the libraries used for okhttp and protobuf:

    compile 'io.grpc:grpc-okhttp:1.21.0'
    compile 'io.grpc:grpc-protobuf:1.20.0'
    compile 'io.grpc:grpc-stub:1.20.0'

These are the libraries used for netty and protobuf:

    compile group: 'io.grpc', name: 'grpc-netty', version: '1.22.1'
    compile group: 'io.netty', name: 'netty-handler', version: '4.1.35.Final'
    compile group: 'io.netty', name: 'netty-tcnative-boringssl-static', version: '2.0.25.Final'
    compile 'io.grpc:grpc-protobuf:1.20.0'
    compile 'io.grpc:grpc-stub:1.20.0'

Any help or lead appreciated.

why mixed in different versions of grpc? i see 1.21.0 1.20.0 1.22.1 do you have complete stacktrace? — creamsoup, Oct 21 '19 at 20:32
@creamsoup no reason in particular, could version difference be an issue? There's no stack trace available — Sahana Nagaraja, Oct 22 '19 at 06:13

Sahana Nagaraja · Accepted Answer · 2020-02-20T09:47:23.260

Solved it by adding keepAliveWithoutCalls as true at client and server side.

public SomeServiceGrpc.SomeServiceBlockingStub getBlockingStub() {

        ManagedChannel channel = OkHttpChannelBuilder
                .forAddress(configuration.getHost(), configuration.getPort())
                .useTransportSecurity()
                .keepAliveTime(1, TimeUnit.MINUTES)
                .keepAliveTimeout(5, TimeUnit.SECONDS)
                .keepAliveWithoutCalls(true)
                .intercept(deadlineInterceptor)
                .build();
        return SomeServiceGrpc.newBlockingStub(channel);
    }

Java netty/okhttp gRPC client throwing intermittent UNAVAILABLE: io exception while trying to connect

1 Answers1