[
https://issues.apache.org/jira/browse/FLINK-10674?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16694650#comment-16694650
]
ASF GitHub Bot commented on FLINK-10674:
----------------------------------------
yanghua commented on issue #7076: [FLINK-10674] [table] Fix
DistinctAccumulator.remove lead to NPE.
URL: https://github.com/apache/flink/pull/7076#issuecomment-440644786
@twalthr
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
> DistinctAccumulator.remove lead to NPE
> --------------------------------------
>
> Key: FLINK-10674
> URL: https://issues.apache.org/jira/browse/FLINK-10674
> Project: Flink
> Issue Type: Bug
> Components: Table API & SQL
> Affects Versions: 1.6.1
> Environment: Flink 1.6.0
> Reporter: ambition
> Assignee: winifredtang
> Priority: Minor
> Labels: pull-request-available
> Attachments: image-2018-10-25-14-46-03-373.png
>
>
> Our online Flink Job run about a week，job contain sql ：
> {code:java}
> select `time`,
> lower(trim(os_type)) as os_type,
> count(distinct feed_id) as feed_total_view
> from my_table
> group by `time`, lower(trim(os_type)){code}
>
> then occur NPE:
>
> {code:java}
> java.lang.NullPointerException
> at scala.Predef$.Long2long(Predef.scala:363)
> at
> org.apache.flink.table.functions.aggfunctions.DistinctAccumulator.remove(DistinctAccumulator.scala:109)
> at NonWindowedAggregationHelper$894.retract(Unknown Source)
> at
> org.apache.flink.table.runtime.aggregate.GroupAggProcessFunction.processElement(GroupAggProcessFunction.scala:124)
> at
> org.apache.flink.table.runtime.aggregate.GroupAggProcessFunction.processElement(GroupAggProcessFunction.scala:39)
> at
> org.apache.flink.streaming.api.operators.LegacyKeyedProcessOperator.processElement(LegacyKeyedProcessOperator.java:88)
> at
> org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:202)
> at
> org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:105)
> 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:745)
> {code}
>
>
> View DistinctAccumulator.remove
> !image-2018-10-25-14-46-03-373.png!
>
> this NPE should currentCnt = null lead to, so we simple handle like :
> {code:java}
> def remove(params: Row): Boolean = {
> if(!distinctValueMap.contains(params)){
> true
> }else{
> val currentCnt = distinctValueMap.get(params)
> //
> if (currentCnt == null || currentCnt == 1) {
> distinctValueMap.remove(params)
> true
> } else {
> var value = currentCnt - 1L
> if(value < 0){
> value = 1
> }
> distinctValueMap.put(params, value)
> false
> }
> }
> }{code}
>
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
