Kafka producer initalization using event Listner plugin makes gravitino unresponsive

[vishnu-chalil]

Hi Team, I was trying to use the event listner plugin in gravitino for capturing the events and sending to kafka topic. But when I initalize the kafka producer in init method it makes the gravitino unresponsive. Iam using kafka client 4.0.0.

Here is the code snipet in init method.

        kafkaProperties = new Properties();
        kafkaProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        kafkaProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
        kafkaProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
        kafkaProducer = new KafkaProducer<>(kafkaProperties);

Whole gravitino becomes unresponsive when this is kafkaProducer = new KafkaProducer<>(kafkaProperties); is executed.

Below is the gravitino logs.

2025-10-01 12:28:26.509 INFO [ForkJoinPool.commonPool-worker-3] [com.zdp.gravitino_plugin.SearchEventListener.getKafkaProducer(SearchEventListener.java:122)] - Creating Kafka producer

2025-10-01 12:28:26.509 INFO [ForkJoinPool.commonPool-worker-3] [com.zdp.gravitino_plugin.SearchEventListener.getKafkaProducer(SearchEventListener.java:123)] - kafka props {value.serializer=org.apache.kafka.common.serialization.StringSerializer, request.timeout.ms=3000, max.block.ms=3000, bootstrap.servers=host.docker.internal:9092, delivery.timeout.ms=5000, key.serializer=org.apache.kafka.common.serialization.StringSerializer}

Is there any recommended approach or restrictions while using EventListenerPlugin?

[mchades]

@FANNG1 cc

[vishnu-chalil]

@mchades @FANNG1 any guidance you can provide on this?

[FANNG1]

Whole gravitino becomes unresponsive

unresponsive You mean the Gravitino server is not responding to the request or there is no logs? could you check the JStack result?

[vishnu-chalil]

Gravitino stops accepting requests. API's doesn't work. In short gravitino doesn't start up. I identified the issue as the dependency of kafka-client was not bundled as part of the jar I provided. Yet instead of not throwing an error ClassNotFound it became idle. Once I added the depedncy the issue was resolved. This was raised as a bug as well but closing this now since issue has been identified.