Hi While I am testing kafka java producer, I saw the following NPE
SLF4J: Failed toString() invocation on an object of type [org.apache.kafka.common.Cluster] java.lang.NullPointerException at org.apache.kafka.common.PartitionInfo.toString(PartitionInfo.java:72) at java.lang.String.valueOf(String.java:2854) at java.lang.StringBuilder.append(StringBuilder.java:128) at java.util.AbstractCollection.toString(AbstractCollection.java:458) at java.lang.String.valueOf(String.java:2854) at java.lang.StringBuilder.append(StringBuilder.java:128) at org.apache.kafka.common.Cluster.toString(Cluster.java:151) at org.slf4j.helpers.MessageFormatter.safeObjectAppend(MessageFormatter.java:305) at org.slf4j.helpers.MessageFormatter.deeplyAppendParameter(MessageFormatter.java:277) at org.slf4j.helpers.MessageFormatter.arrayFormat(MessageFormatter.java:231) at org.slf4j.helpers.MessageFormatter.format(MessageFormatter.java:152) at org.slf4j.impl.Log4jLoggerAdapter.debug(Log4jLoggerAdapter.java:251) at org.apache.kafka.clients.producer.internals.Metadata.update(Metadata.java:133) at org.apache.kafka.clients.NetworkClient.handleMetadataResponse(NetworkClient.java:299) at org.apache.kafka.clients.NetworkClient.handleCompletedReceives(NetworkClient.java:284) at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:185) at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:175) at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:115) at java.lang.Thread.run(Thread.java:744) This looks like not critical because it's debug() statement but this NPE means potential threat in kafka producer stableness. Do you have any idea? If you want, I can share my test code. Thank you Best, Jae
