2
votes

I am getting the following error

org.apache.flink.shaded.netty4.io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: localhost/127.0.0.1:8081

while trying to stream data with Flink. My code was functioning fine about a month ago and now I am getting this error. Before I was also able to monitor the streaming progress by accessesing Flink Web Dashboard on http://localhost:8081 and now my browser returns an error that it can not access the server "localhost". What could be the problem? Thank you in advance.

The full output of error message:

org.apache.flink.client.program.ProgramInvocationException: Could not retrieve the execution result. (JobID: cfa44a8fd6a62f51ef8c0f956d55ee56) at org.apache.flink.client.program.rest.RestClusterClient.submitJob(RestClusterClient.java:260) at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:486) at org.apache.flink.streaming.api.environment.StreamContextEnvironment.execute(StreamContextEnvironment.java:66) at examples.WaterLevelKafka.main(WaterLevelKafka.java:124) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:529) at org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:421) at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:426) at org.apache.flink.client.cli.CliFrontend.executeProgram(CliFrontend.java:804) at org.apache.flink.client.cli.CliFrontend.runProgram(CliFrontend.java:280) at org.apache.flink.client.cli.CliFrontend.run(CliFrontend.java:215) at org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:1044) at org.apache.flink.client.cli.CliFrontend.lambda$main$11(CliFrontend.java:1120) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:422) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1836) at org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:41) at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:1120) Caused by: org.apache.flink.runtime.client.JobSubmissionException: Failed to submit JobGraph. at org.apache.flink.client.program.rest.RestClusterClient.lambda$submitJob$8(RestClusterClient.java:379) at java.util.concurrent.CompletableFuture.uniExceptionally(CompletableFuture.java:870) at java.util.concurrent.CompletableFuture$UniExceptionally.tryFire(CompletableFuture.java:852) at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474) at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1977) at org.apache.flink.runtime.concurrent.FutureUtils.lambda$retryOperationWithDelay$5(FutureUtils.java:213) at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760) at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736) at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474) at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1977) at org.apache.flink.runtime.rest.RestClient.lambda$submitRequest$1(RestClient.java:276) at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511) at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:504) at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:483) at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424) at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:121) at org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.fulfillConnectPromise(AbstractNioChannel.java:327) at org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:343) at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:633) at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580) at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497) at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459) at org.apache.flink.shaded.netty4.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884) at org.apache.flink.shaded.netty4.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) at java.lang.Thread.run(Thread.java:745) Caused by: java.util.concurrent.CompletionException: org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not complete the operation. Number of retries has been exhausted. at java.util.concurrent.CompletableFuture.encodeRelay(CompletableFuture.java:326) at java.util.concurrent.CompletableFuture.completeRelay(CompletableFuture.java:338) at java.util.concurrent.CompletableFuture.uniRelay(CompletableFuture.java:911) at java.util.concurrent.CompletableFuture$UniRelay.tryFire(CompletableFuture.java:899) ... 22 more Caused by: org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not complete the operation. Number of retries has been exhausted. ... 20 more Caused by: java.util.concurrent.CompletionException: org.apache.flink.shaded.netty4.io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: localhost/127.0.0.1:8081 at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:292) at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:308) at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:943) at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:926) ... 17 more Caused by: org.apache.flink.shaded.netty4.io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: localhost/127.0.0.1:8081 at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) at org.apache.flink.shaded.netty4.io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:325) at org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:340) ... 7 more Caused by: java.net.ConnectException: Connection refused ... 11 more

1
Can you make sure that Flink is actually running. If it does, then the logs would be interesting to see. - Till Rohrmann
Thank you @TillRohrmann, indeed the Flink cluster was not running. - Anemone

1 Answers

4
votes

It seems that the Apache flink cluster is not running.

You need just to start it :

./bin/start-cluster.sh  # Start Flink