NoSuchMethod Error (Standalone)

[mattdonders]

I build the connector (V3.3.0) from source using Maven -

$ cd kafka-connect-elasticsearch
$ mvn clean package

I then created the require configuration file -

name=es-cluster-lab
connector.class=io.confluent.connect.elasticsearch.ElasticsearchSinkConnector
tasks.max=1
topics=filebeats-test
topic.index.map=filebeats-test:kafka_test_index
key.ignore=true
schema-ignore=true
connection.url=http://elastic:9200
type.name=log

As per the new Kafka Classpath Isolation spec, I also added the following line to my connect-standalone.properties file -

plugin.path=/home/kafka/kafka-connect-elasticsearch-3.3.0/target/kafka-connect-elasticsearch-3.3.0-development/share/java/kafka-connect-elasticsearch/

I go to run the script ...

bin/connect-standalone.sh config/connect-standalone.properties config/elasticsearch-connect.properties

... and receive the below error.

[2017-09-14 16:08:26,599] INFO Loading plugin from: /home/kafka/kafka-connect-elasticsearch-3.3.0/target/kafka-connect-elasticsearch-3.3.0-development/share/java/kafka-connect-elasticsearch/slf4j-api-1.7.25.jar (org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader:176)
Exception in thread "main" java.lang.NoSuchMethodError: com.google.common.collect.Sets$SetView.iterator()Lcom/google/common/collect/UnmodifiableIterator;
        at org.reflections.Reflections.expandSuperTypes(Reflections.java:380)
        at org.reflections.Reflections.<init>(Reflections.java:126)
        at org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader.scanPluginPath(DelegatingClassLoader.java:221)
        at org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader.scanUrlsAndAddPlugins(DelegatingClassLoader.java:198)
        at org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader.registerPlugin(DelegatingClassLoader.java:190)
        at org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader.initLoaders(DelegatingClassLoader.java:150)
        at org.apache.kafka.connect.runtime.isolation.Plugins.<init>(Plugins.java:47)
        at org.apache.kafka.connect.cli.ConnectStandalone.main(ConnectStandalone.java:68)

I also tried to move the JAR files into the /app/kafka/libs directory (default CLASSPATH) and even tried to create a subdirectory /app/kafka/libs/connect_libs and add that manually to my CLASSPATH environment variable.

Not sure what my next step is besides putting Logstash between Kafka and Elastic.

[kkonstantine]

The plugin.path needs to contain directories of connector jars with their dependencies, or uber jars.

In your example a functional plugin.path would be:
plugin.path=/home/kafka/kafka-connect-elasticsearch-3.3.0/target/kafka-connect-elasticsearch-3.3.0-development/share/java

See also #143