ClassNotFoundException: org.apache.flink.streaming.api.checkpoint.CheckpointNotifier while consuming a kafka topic

问题

I am using the latest Flink-1.1.2-Hadoop-27 and flink-connector-kafka-0.10.2-hadoop1 jars.

Flink consumer is as below:

StreamExecutionEnvironment env=StreamExecutionEnvironment.getExecutionEnvironment();
        if (properties == null) {
            properties = new Properties();
            InputStream props = Resources.getResource(KAFKA_CONFIGURATION_FILE).openStream();
            properties.load(props);

            DataStream<String> stream = env.addSource(new FlinkKafkaConsumer082<>(KAFKA_SIP_TOPIC, new SimpleStringSchema() , properties));

Following is the exception I get after executing:

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/flink/streaming/api/checkpoint/CheckpointNotifier
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.bt.oss.voice.main.FlnkConsumer.main(FlnkConsumer.java:50)Caused by: java.lang.ClassNotFoundException: org.apache.flink.streaming.api.checkpoint.CheckpointNotifier
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 25 more

回答1:

You are mixing versions. A Kafka consumer for Flink 0.10.2 will not work with Flink 1.1.2.

You should use the Kafka connector provided with Flink 1.1.2 and include the following Maven dependency:

<dependency>
  <groupId>org.apache.flink</groupId>
  <artifactId>flink-connector-kafka-0.8_2.10</artifactId>
  <version>1.1.2</version>
</dependency>

Please check out the documentation for details.

回答2:

In case using sbt, the following update in flink scala dependencies solved my issue.

"org.apache.flink" %% "flink-scala" % flinkVersion % "provided",
"org.apache.flink" %% "flink-streaming-scala" % flinkVersion % "provided",

to:

"org.apache.flink" %% "flink-scala" % flinkVersion,
"org.apache.flink" %% "flink-streaming-scala" % flinkVersion,

来源：https://stackoverflow.com/questions/40037047/classnotfoundexception-org-apache-flink-streaming-api-checkpoint-checkpointnoti

标签

apache-kafka

apache-flink

flink-streaming