Uwe, Great, I'm glad that you were able to get it resolved! I agree, throwing an NPE is never okay and is absolutely a bug. If there is no Record present, we should provide a reasonable error message.
It may actually make sense to change the name of that property as well. Instead of "Skip Header Line" perhaps change it to "Treat First Line as Header" Thanks -Mark > On Jun 22, 2017, at 4:34 PM, Uwe Geercken <[email protected]> wrote: > > Mark, > > yes it was the skip header line. Damn it - so many hours..... > > Actually - as a non native english speaker - it was a misinterpretation of > what that means. I interpreted it as "there is no header line". But reading > the help for this property againa and again, I see that I just didn't read it > carefully enough. Anyway, a better exception message would have helped me > maybe. > > Thank you Mark - you made my day. > > Greetings, > > Uwe > > > Gesendet: Donnerstag, 22. Juni 2017 um 22:23 Uhr > Von: "Mark Payne" <[email protected]> > An: "[email protected]" <[email protected]> > Betreff: Re: Nifi 1.3.0 - Problems with ConsumeKafkaRecord_0_10 > Uwe, > > We do have a JIRA to address an issue where ConsumeKafkaRecord expects that > exactly one Record exists per > Kafka message. If you retrieve a Kafka message that has no records, you'll > get a NPE. Is there any chance that > you're reading a 0-byte message from Kafka? > > Also, on your CSV Reader, do you have the "Skip Header Line" property set to > "true"? This is the default, and if > this is the case, it is reading your message as the header. As a result, it > is finding 0 records in the Kafka message > because the stream ends after reading the "header." Since you don't have a > header on your CSV data, you'll > want to make sure that Skip Header Line is set to false. > > Thanks > -Mark > > >> On Jun 22, 2017, at 3:54 PM, Matt Burgess <[email protected]> wrote: >> >> Uwe, >> >> It looks like this error is directly related to your other question. >> This line from the stack trace: >> >> Caused by: java.lang.NullPointerException: null >> at >> org.apache.nifi.processors.kafka.pubsub.ConsumerLease.writeRecordData(ConsumerLease.java:458) >> >> Is when it calls record.getSchema(). Not sure if the "real" error >> message is getting lost or perhaps further down in your stack trace, >> but it looks like an error with finding or reading the schema. >> >> Regards, >> Matt >> >> >> On Thu, Jun 22, 2017 at 3:30 PM, Uwe Geercken <[email protected]> wrote: >>> Hello everyone, >>> >>> I wanted to try the following >>> - get messages from a kafka topic. these are simple messages in CSV format >>> - use the PartitionRecord processor to get familiar with the RecordPath >>> concept >>> >>> I started zookeeper and kafka on localhost and added some messages to a >>> topic using the kafka concole producer. A message looks like this: >>> >>> ZRH,departure,LX,1000,F,2017-06-22,10:00,2017-06-22,10:05,200 >>> >>> I can retrieve this message using the kafka concole consumer. >>> >>> To my flow I added the ConsumeKafkaRecord_0_10 and the PartitionRecord >>> processor. I configured the ConsumeKafkaRecord_0_10 with a CSVReader >>> controller. It uses the AvroSchemaRegistry 1.3.0 with following schema: >>> >>> { >>> "type": "record", >>> "name": "flight_schema", >>> "fields": [ >>> { "name": "flight_station", "type": "string" }, >>> { "name": "flight_orientation", "type": "string" }, >>> { "name": "flight_carrier", "type": "string" }, >>> { "name": "flight_number", "type": "string" }, >>> { "name": "flight_number_suffix", "type": "string" }, >>> { "name": "flight_scheduled_date", "type": "string" }, >>> { "name": "flight_scheduled_time", "type": "string" }, >>> { "name": "flight_actual_date", "type": "string" }, >>> { "name": "flight_actual_time", "type": "string" }, >>> { "name": "flight_passengers", "type": "int" } >>> ] >>> } >>> >>> And then I have a CSVRecordWriter which uses the same schema. I also added >>> a line to logback.xml to debug the ConsumeKafkaRecord_0_10 processor. >>> >>> Now when I run the processors and add a message to the topic in kafka I get >>> following error: >>> >>> >>> 2017-06-22 18:32:11,228 ERROR [Timer-Driven Process Thread-7] >>> o.a.n.p.k.pubsub.ConsumeKafkaRecord_0_10 >>> ConsumeKafkaRecord_0_10[id=cb353b32-015c-1000-0ed2-0753cceaa542] Exception >>> while processing data from kafka so will close the lease >>> org.apache.nifi.processors.kafka.pubsub.ConsumerPool$SimpleConsumerLease@4f137cc2 >>> due to org.apache.nifi.processor.exception.ProcessException: >>> java.lang.NullPointerException: >>> org.apache.nifi.processor.exception.ProcessException: >>> java.lang.NullPointerException >>> org.apache.nifi.processor.exception.ProcessException: >>> java.lang.NullPointerException >>> at >>> org.apache.nifi.processors.kafka.pubsub.ConsumerLease.writeRecordData(ConsumerLease.java:514) >>> at >>> org.apache.nifi.processors.kafka.pubsub.ConsumerLease.lambda$processRecords$8(ConsumerLease.java:320) >>> at java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1548) >>> at >>> java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580) >>> at >>> org.apache.nifi.processors.kafka.pubsub.ConsumerLease.processRecords(ConsumerLease.java:307) >>> at >>> org.apache.nifi.processors.kafka.pubsub.ConsumerLease.poll(ConsumerLease.java:168) >>> at >>> org.apache.nifi.processors.kafka.pubsub.ConsumeKafkaRecord_0_10.onTrigger(ConsumeKafkaRecord_0_10.java:327) >>> at >>> org.apache.nifi.processor.AbstractProcessor.onTrigger(AbstractProcessor.java:27) >>> at >>> org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1120) >>> at >>> org.apache.nifi.controller.tasks.ContinuallyRunProcessorTask.call(ContinuallyRunProcessorTask.java:147) >>> at >>> org.apache.nifi.controller.tasks.ContinuallyRunProcessorTask.call(ContinuallyRunProcessorTask.java:47) >>> at >>> org.apache.nifi.controller.scheduling.TimerDrivenSchedulingAgent$1.run(TimerDrivenSchedulingAgent.java:132) >>> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) >>> at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) >>> at >>> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) >>> at >>> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) >>> at >>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) >>> at >>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) >>> at java.lang.Thread.run(Thread.java:748) >>> Caused by: java.lang.NullPointerException: null >>> at >>> org.apache.nifi.processors.kafka.pubsub.ConsumerLease.writeRecordData(ConsumerLease.java:458) >>> ... 18 common frames omitted >>> >>> >>> >>> I have played around with the settings of the processors and controllers >>> quite a lot, but always get this NullPointerException. >>> >>> I then added a ConsumeKafka_0_10 1.3.0 processor to verify that I can >>> retrieve the messages and it does work. >>> >>> I hope that someone can point out what the problem is and help me. >>> >>> Greetings, >>> >>> Uwe >
