Uwe, Actually I spoke too soon; although it might end up being a schema issue, the NPE looks like it is caused when the record itself is null, which can happen in the code (there is no null check before trying to get the schema from the record). However this might still be a schema issue if the Reader can be instantiated but then it retrieves no records. Or it might be a bug in the processor's handling of the Kafka input which might be empty? That's all the guessing I'll do on the Kafka stuff, I'll leave it to the folks that know much more about it :)
Regards, Matt On Thu, 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
