[KAFKA-9717] KafkaStreams#metrics() method randomly throws NullPointerException

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.2.0
• Component/s: streams
• Environment: Kubernetes
• Assignee: Unassigned
• Reporter: Zygimantas
• Created: 13/Mar/20 10:51
• Updated: 01/Jun/20 16:38

Description

We have implemented monitoring tool which monitors Kafka Streams application and regularly (every 20s) calls KafkaStreams.metrics() method in that application. But metrics() method randomly throws NullPointerException. It happens almost every time after application startup, but may also happen at random points in time after running application for few hours.

Stacktrace:

java.lang.NullPointerException
 at org.apache.kafka.streams.processor.internals.StreamThread.producerMetrics(StreamThread.java:1320)
 at org.apache.kafka.streams.KafkaStreams.metrics(KafkaStreams.java:379)