[FLINK-12504] NullPoint here NullPointException there.. It's every where

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Bug
• Component/s: API / DataStream
• Assignee: Unassigned
• Reporter: Chethan UK
• Created: 13/May/19 18:02
• Updated: 15/May/19 14:18
• Resolved: 15/May/19 14:18

Description

I was trying to push data from Kafka to Cassandra, after around 220K sometimes, 300K points are pushed into C*, this java.lang.NullPointerException throws in..

```
java.lang.NullPointerException
at org.apache.flink.api.common.functions.util.PrintSinkOutputWriter.write(PrintSinkOutputWriter.java:73)
at org.apache.flink.streaming.api.functions.sink.PrintSinkFunction.invoke(PrintSinkFunction.java:81)
at org.apache.flink.streaming.api.functions.sink.SinkFunction.invoke(SinkFunction.java:52)
at org.apache.flink.streaming.api.operators.StreamSink.processElement(StreamSink.java:56)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.pushToOperator(OperatorChain.java:579)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.collect(OperatorChain.java:554)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.collect(OperatorChain.java:534)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$BroadcastingOutputCollector.collect(OperatorChain.java:649)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$BroadcastingOutputCollector.collect(OperatorChain.java:602)
at org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:718)
at org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:696)
at org.apache.flink.streaming.api.operators.StreamMap.processElement(StreamMap.java:41)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.pushToOperator(OperatorChain.java:579)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.collect(OperatorChain.java:554)
at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.collect(OperatorChain.java:534)
at org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:718)
at org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:696)
at org.apache.flink.streaming.api.operators.StreamSourceContexts$NonTimestampContext.collect(StreamSourceContexts.java:104)
at org.apache.flink.streaming.api.operators.StreamSourceContexts$NonTimestampContext.collectWithTimestamp(StreamSourceContexts.java:111)
at org.apache.flink.streaming.connectors.kafka.internals.AbstractFetcher.emitRecordWithTimestamp(AbstractFetcher.java:398)
at org.apache.flink.streaming.connectors.kafka.internal.KafkaFetcher.emitRecord(KafkaFetcher.java:185)
at org.apache.flink.streaming.connectors.kafka.internal.KafkaFetcher.runFetchLoop(KafkaFetcher.java:150)
at org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumerBase.run(FlinkKafkaConsumerBase.java:711)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:93)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:57)
at org.apache.flink.streaming.runtime.tasks.SourceStreamTask.run(SourceStreamTask.java:97)
at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:300)
at org.apache.flink.runtime.taskmanager.Task.run(Task.java:711)
at java.lang.Thread.run(Thread.java:748)
```

How can normal Flink Users understand these error? The Job's keep failing and it's very unstable to be considered in production... 

 

In RoadMap, is there plans to make Kotlin supported language as well?