Socket Window WordCounter example error about docker-flink

Here's the task executor log in case needed:

2018-07-29 02:14:09,195 INFO org.apache.flink.runtime.taskmanager.Task - Loading JAR files for task Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11) [DEPLOYING].
2018-07-29 02:14:09,201 INFO org.apache.flink.runtime.taskmanager.Task - Registering task at network: Source: Socket Stream -> Flat Map (1/1) (483be8dafa58cb264aaa82ffdc21fefc) [DEPLOYING].
2018-07-29 02:14:09,215 INFO org.apache.flink.runtime.taskmanager.Task - Registering task at network: Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11) [DEPLOYING].
2018-07-29 02:14:09,336 INFO org.apache.flink.runtime.taskmanager.Task - Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11) switched from DEPLOYING to RUNNING.
2018-07-29 02:14:09,416 INFO org.apache.flink.streaming.runtime.tasks.StreamTask - No state backend has been configured, using default (Memory / JobManager) MemoryStateBackend (data in heap memory / checkpoints to JobManager) (checkpoints: 'null', savepoints: 'null', asynchronous: TRUE, maxStateSize: 5242880)
2018-07-29 02:14:09,571 INFO org.apache.flink.runtime.taskmanager.Task - Source: Socket Stream -> Flat Map (1/1) (483be8dafa58cb264aaa82ffdc21fefc) switched from DEPLOYING to RUNNING.
2018-07-29 02:14:09,577 INFO org.apache.flink.streaming.runtime.tasks.StreamTask - No state backend has been configured, using default (Memory / JobManager) MemoryStateBackend (data in heap memory / checkpoints to JobManager) (checkpoints: 'null', savepoints: 'null', asynchronous: TRUE, maxStateSize: 5242880)
2018-07-29 02:14:09,762 WARN org.apache.flink.metrics.MetricGroup - The operator name Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) exceeded the 80 characters length limit and was truncated.
2018-07-29 02:14:09,922 INFO org.apache.flink.runtime.state.heap.HeapKeyedStateBackend - Initializing heap keyed state backend with stream factory.
2018-07-29 02:14:09,948 INFO org.apache.flink.streaming.api.functions.source.SocketTextStreamFunction - Connecting to server socket localhost:9000
2018-07-29 02:14:10,069 INFO org.apache.flink.runtime.taskmanager.Task - Source: Socket Stream -> Flat Map (1/1) (483be8dafa58cb264aaa82ffdc21fefc) switched from RUNNING to FAILED.
java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at org.apache.flink.streaming.api.functions.source.SocketTextStreamFunction.run(SocketTextStreamFunction.java:96)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:87)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:56)
at org.apache.flink.streaming.runtime.tasks.SourceStreamTask.run(SourceStreamTask.java:99)
at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:306)
at org.apache.flink.runtime.taskmanager.Task.run(Task.java:703)
at java.lang.Thread.run(Thread.java:748)
2018-07-29 02:14:10,086 INFO org.apache.flink.runtime.taskmanager.Task - Freeing task resources for Source: Socket Stream -> Flat Map (1/1) (483be8dafa58cb264aaa82ffdc21fefc).
2018-07-29 02:14:10,105 INFO org.apache.flink.runtime.taskmanager.Task - Ensuring all FileSystem streams are closed for task Source: Socket Stream -> Flat Map (1/1) (483be8dafa58cb264aaa82ffdc21fefc) [FAILED]
2018-07-29 02:14:10,106 INFO org.apache.flink.runtime.taskexecutor.TaskExecutor - Un-registering task and sending final execution state FAILED to JobManager for task Source: Socket Stream -> Flat Map 483be8dafa58cb264aaa82ffdc21fefc.
2018-07-29 02:14:10,147 INFO org.apache.flink.runtime.taskexecutor.TaskExecutor - Discarding the results produced by task execution 483be8dafa58cb264aaa82ffdc21fefc.
2018-07-29 02:14:10,148 INFO org.apache.flink.runtime.taskmanager.Task - Attempting to cancel task Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11).
2018-07-29 02:14:10,148 INFO org.apache.flink.runtime.taskmanager.Task - Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11) switched from RUNNING to CANCELING.
2018-07-29 02:14:10,149 INFO org.apache.flink.runtime.taskmanager.Task - Triggering cancellation of task code Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11).
2018-07-29 02:14:10,153 INFO org.apache.flink.runtime.taskmanager.Task - Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11) switched from CANCELING to CANCELED.
2018-07-29 02:14:10,153 INFO org.apache.flink.runtime.taskmanager.Task - Freeing task resources for Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11).
2018-07-29 02:14:10,155 INFO org.apache.flink.runtime.taskmanager.Task - Ensuring all FileSystem streams are closed for task Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out (1/1) (facb0e372cc07e9dec1dba853243ec11) [CANCELED]
2018-07-29 02:14:10,156 INFO org.apache.flink.runtime.taskexecutor.TaskExecutor - Un-registering task and sending final execution state CANCELED to JobManager for task Window(TumblingProcessingTimeWindows(5000), ProcessingTimeTrigger, ReduceFunction$1, PassThroughWindowFunction) -> Sink: Print to Std. Out facb0e372cc07e9dec1dba853243ec11.
2018-07-29 02:14:10,196 INFO org.apache.flink.runtime.taskexecutor.TaskExecutor - Close JobManager connection for job d05643637b5025eb27806d67fa91285f.
2018-07-29 02:14:10,205 INFO org.apache.flink.runtime.taskexecutor.slot.TaskSlotTable - Free slot TaskSlot(index:0, state:ALLOCATED, resource profile: ResourceProfile{cpuCores=1.0, heapMemoryInMB=42, directMemoryInMB=0, nativeMemoryInMB=0, networkMemoryInMB=0}, allocationId: b7a744239795cd6a6afb9da1fb488b53, jobId: d05643637b5025eb27806d67fa91285f).
2018-07-29 02:14:10,206 INFO org.apache.flink.runtime.taskexecutor.JobLeaderService - Remove job d05643637b5025eb27806d67fa91285f from job leader monitoring.
2018-07-29 02:14:10,206 INFO org.apache.flink.runtime.taskexecutor.TaskExecutor - Close JobManager connection for job d05643637b5025eb27806d67fa91285f.

[patricklucas]

tl;dr: use nc -l -p 9000 instead of nc -l 9000.

Debian ships with two versions of netcat, netcat-openbsd and netcat-traditional, and when you just apt-get install netcat you get netcat-traditional.

You can demonstrate this by first running apt-get install net-tools netcat-openbsd netcat-traditional, then:

• nc.traditional -l 9000
• netstat -ptunl
• Note that there is an nc process listening, but not on port 9000
• nc.traditional -l -p 9000
• netstat -ptunl
• It's listening now on :9000
• nc.openbsd -l 9000
• Also listens on :9000

Hope this helps!

That did it! Thank you for the quick help Patrick...