good morning all. i'm finally back to playing with the kafka plugin. i have a very simple job with a kafka producer as the last task. when i submit it, i get the following (abbreviated trace): ` ...onyx.peer.task-lifecycle/instantiate-plugin task_lifecycle.clj: 489 ... onyx.plugin.kafka/write-messages kafka.clj: 291 onyx.kafka.helpers/id->broker helpers.clj: 80 onyx.kafka.helpers/all-brokers helpers.clj: 58 java.lang.ClassCastException: scala.collection.immutable.Nil$ cannot be cast to scala.collection.mutable.Buffer clojure.lang.ExceptionInfo: Caught exception inside task lifecycle :lifecycle/initializing. Rebooting the task. -> Exception type: java.lang.ClassCastException. Exception message: scala.collection.immutable.Nil$ cannot be cast to scala.collection.mutable.Buffer job-id: #uuid "1ef4720f-9887-80c3-2edc-3d5a5e15b010" metadata: {:job-id #uuid "1ef4720f-9887-80c3-2edc-3d5a5e15b010", :job-hash "1933e73c0103a59276019ce8b68b95f59923c1192860a320da169e6e4abc2e"} peer-id: #uuid "65c21b2a-cc67-3488-961e-be4bb7146ec4" task-name: :kafka-out ` Catalog entry for it @ submission time is: ` {:kafka/zookeeper "127.0.0.1:2188", :onyx/plugin :onyx.plugin.kafka/write-messages, :onyx/medium :kafka, :onyx/type :output, :onyx/name :kafka-out, :kafka/topic "test-topic", :kafka/serializer-fn :onyx.tasks.kafka/serialize-message-edn, :onyx/max-peers 1, :onyx/doc "Writes segments to the Kafka test topic", :onyx/batch-size 10} ` anyone seen this before/have any ideas? since i'm a complete noob in all this, i'm hoping it's operator error & something glaringly simple/obvious... 😀

ugh. sorry about formatting. i'm a Slack noob too 😞

@brianh What version of the Onyx Kafka plugin and what version of Kafka are you using?

@gardnervickers thanks! your question caused me to notice i'd forgotten to start the kafka server (odd error for that...). once i started it, it worked. knew it was something simple... 😀

:thumbsup: