[FLINK-18196] flink throws `NullPointerException` when executeCheckpointing

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 1.10.0, 1.10.1
• Fix Version/s: 1.10.3, 1.11.3, 1.12.0
• Component/s: Runtime / Checkpointing

Environment

flink version: flink-1.10.0 flink-1.10.1
jdk version: jdk1.8.0_40

• Assignee: Unassigned
• Reporter: Kai Chen
• Created: 09/Jun/20 02:44
• Updated: 14/Oct/20 09:07
• Resolved: 09/Oct/20 17:30

Description

I meet checkpoint NPE when executing wordcount example:

java.lang.Exception: Could not perform checkpoint 5505 for operator Source: KafkaTableSource(xxx) > SourceConversion(table=[xxx, source: [KafkaTableSource(xxx)]], fields=[xxx]) > Calc(select=[xxx) AS xxx]) > SinkConversionToTuple2  --  > Sink: Elasticsearch6UpsertTableSink(xxx) (1/1).

    at org.apache.flink.streaming.runtime.tasks.StreamTask.triggerCheckpoint(StreamTask.java:802)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.lambda$triggerCheckpointAsync$3(StreamTask.java:777)

    at org.apache.flink.streaming.runtime.tasks.StreamTask$$Lambda$228/1024478318.call(Unknown Source)

    at java.util.concurrent.FutureTask.run(FutureTask.java:266)

    at org.apache.flink.streaming.runtime.tasks.StreamTaskActionExecutor$SynchronizedStreamTaskActionExecutor.run(StreamTaskActionExecutor.java:87)

    at org.apache.flink.streaming.runtime.tasks.mailbox.Mail.run(Mail.java:78)

    at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.processMail(MailboxProcessor.java:261)

    at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.runMailboxLoop(MailboxProcessor.java:186)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.runMailboxLoop(StreamTask.java:487)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:470)

    at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:707)

    at org.apache.flink.runtime.taskmanager.Task.run(Task.java:532)

    at java.lang.Thread.run(Thread.java:745)

Caused by: java.lang.NullPointerException

    at org.apache.flink.streaming.runtime.tasks.StreamTask$CheckpointingOperation.executeCheckpointing(StreamTask.java:1411)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.checkpointState(StreamTask.java:991)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.lambda$performCheckpoint$5(StreamTask.java:887)

    at org.apache.flink.streaming.runtime.tasks.StreamTask$$Lambda$229/1010499540.run(Unknown Source)

    at org.apache.flink.streaming.runtime.tasks.StreamTaskActionExecutor$SynchronizedStreamTaskActionExecutor.runThrowing(StreamTaskActionExecutor.java:94)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.performCheckpoint(StreamTask.java:860)

    at org.apache.flink.streaming.runtime.tasks.StreamTask.triggerCheckpoint(StreamTask.java:793)

    ... 12 more

 

checkpoint configuration

Checkpointing Mode	Exactly Once
Interval	5s
Timeout	10m 0s
Minimum Pause Between Checkpoints	0ms
Maximum Concurrent Checkpoints	1

With debug enabled, I found `checkpointMetaData`  is null at

 https://github.com/apache/flink/blob/release-1.10.0/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/StreamTask.java#L1421

 

I fixed this with this patch: https://github.com/yuchuanchen/flink/commit/e5122d9787be1fee9bce141887e0d70c9b0a4f19

Issue Links

• is duplicated by: FLINK-17479 Occasional checkpoint failure due to null pointer exception in Flink version 1.10