[dgraph4j] Using java client connect to dgraph alpha failed. (docker on AWS EC2)

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1

Hi all.
I started a dgraph service in docker on AWS EC2.

CONTAINER ID        IMAGE                                        COMMAND                  CREATED             STATUS              PORTS                                                                                                                    NAMES
e18eef8db87a        dgraph/dgraph                                "dgraph zero"            5 hours ago         Up 5 hours          0.0.0.0:5080->5080/tcp, 0.0.0.0:6080->6080/tcp, 0.0.0.0:8000->8000/tcp, 0.0.0.0:8080->8080/tcp, 0.0.0.0:9080->9080/tcp   dgraph

But failed to connect to the dgraph server when I run my java client locally.
When the code runs at transaction.commit();, it will hangs for several minutes and printout:

java.lang.RuntimeException: java.util.concurrent.CompletionException: java.lang.RuntimeException: The doRequest encountered an execution exception:

	at io.dgraph.AsyncTransaction.lambda$doRequest$2(AsyncTransaction.java:173)
	at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:930)
	at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:907)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run$$$capture(CompletableFuture.java:1705)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1692)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:177)
Caused by: java.util.concurrent.CompletionException: java.lang.RuntimeException: The doRequest encountered an execution exception:
	at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:314)
	at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:319)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run$$$capture(CompletableFuture.java:1702)
	... 7 more
Caused by: java.lang.RuntimeException: The doRequest encountered an execution exception:
	at io.dgraph.DgraphAsyncClient.lambda$runWithRetries$2(DgraphAsyncClient.java:212)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run$$$capture(CompletableFuture.java:1700)
	... 7 more
Caused by: java.util.concurrent.ExecutionException: io.grpc.StatusRuntimeException: UNAVAILABLE: Connection closed while performing protocol negotiation for [HttpClientCodec#0, HttpProxyHandler#0, ProtocolNegotiators$WaitUntilActiveHandler#0, WriteBufferingAndExceptionHandler#0, DefaultChannelPipeline$TailContext#0]
	at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:395)
	at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1999)
	at io.dgraph.DgraphAsyncClient.lambda$runWithRetries$2(DgraphAsyncClient.java:180)
	... 8 more
Caused by: io.grpc.StatusRuntimeException: UNAVAILABLE: Connection closed while performing protocol negotiation for [HttpClientCodec#0, HttpProxyHandler#0, ProtocolNegotiators$WaitUntilActiveHandler#0, WriteBufferingAndExceptionHandler#0, DefaultChannelPipeline$TailContext#0]
	at io.grpc.Status.asRuntimeException(Status.java:533)
	at io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onClose(ClientCalls.java:442)
	at io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)
	at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)
	at io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)
	at io.grpc.internal.CensusStatsModule$StatsClientInterceptor$1$1.onClose(CensusStatsModule.java:700)
	at io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)
	at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)
	at io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)
	at io.grpc.internal.CensusTracingModule$TracingClientInterceptor$1$1.onClose(CensusTracingModule.java:399)
	at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:507)
	at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:66)
	at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:627)
	at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$700(ClientCallImpl.java:515)
	at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:686)
	at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:675)
	at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
	at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:834

It seems some errors happen when communicate to the server via grpc:

io.grpc.StatusRuntimeException: UNAVAILABLE: Connection closed while performing protocol negotiation for [HttpClientCodec#0, HttpProxyHandler#0, ProtocolNegotiators$WaitUntilActiveHandler#0, WriteBufferingAndExceptionHandler#0, DefaultChannelPipeline$TailContext#0]

The dependency info:

    <dependency>
      <groupId>io.dgraph</groupId>
      <artifactId>dgraph4j</artifactId>
      <version>2.0.2</version>
    </dependency>

    <dependency>
      <groupId>com.google.protobuf</groupId>
      <artifactId>protobuf-java</artifactId>
      <version>3.7.1</version>
    </dependency>

And, I can netcat to the server IP and port from my local terminal:

$ nc -zv 172.31.39.245 9080
Connection to 172.31.39.245 port 9080 [tcp/glrpc] succeeded!

Also can open the Ratel UI, connect to the Dgraph server: http://172.31.39.245:8080/ or POST an /alter request.

When I run the dgraph service in docker on my local environment, the java client runs good and no exception.

Can anyone help me out with this grpc issue?

Thank you!

2

Resolved.

It’s grpc issue. I excluded the grpc related dependencies in dgraph4j and added the newest version:

    <dependency>
      <groupId>com.google.protobuf</groupId>
      <artifactId>protobuf-java</artifactId>
      <version>3.11.1</version>
    </dependency>

    <dependency>
      <groupId>io.dgraph</groupId>
      <artifactId>dgraph4j</artifactId>
      <version>2.0.2</version>
      <exclusions>
        <exclusion>
          <groupId>io.grpc</groupId>
          <artifactId>grpc-protobuf</artifactId>
        </exclusion>
        <exclusion>
          <groupId>io.grpc</groupId>
          <artifactId>grpc-stub</artifactId>
        </exclusion>
        <exclusion>
          <groupId>io.grpc</groupId>
          <artifactId>grpc-netty</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

    <dependency>
      <groupId>io.grpc</groupId>
      <artifactId>grpc-protobuf</artifactId>
      <version>1.26.0</version>
    </dependency>
    <dependency>
      <groupId>io.grpc</groupId>
      <artifactId>grpc-stub</artifactId>
      <version>1.26.0</version>
    </dependency>
    <dependency>
      <groupId>io.grpc</groupId>
      <artifactId>grpc-netty</artifactId>
      <version>1.26.0</version>
    </dependency>

It works and no exceptions occur.

Related link: Missing connections behind proxy · Issue #21 · googleapis/java-dialogflow · GitHub

1 Like
3

I think we should upgrade the related grpc dependencies version in dgraph4j.

4

Hey Zxh,

Thank you for sharing the solution, that kind of approach helps a lot of people! About the dgraph4j dependencies. Would you mind to open an issue at Issues · dgraph-io/dgraph4j · GitHub mentioning this topic?

Cheers.

5

Thanks for your reminder, I created a related issue in dgraph4j project and mentioned this topic.
You can view at: Need to upgrade the related gRPC dependencies. · Issue #124 · dgraph-io/dgraph4j · GitHub

Thanks.

2 Likes
6

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