Failed to find any class that implements Connector and which name matches com.mongodb.kafka.connect.MongoSinkConnector

Question

I don't use confluent, just use apache kafka, already add mongo plugin, get ... / connector-plugins response, list the MongoSinkConnector

[
{
    "class": "com.mongodb.kafka.connect.MongoSinkConnector",
    "type": "sink",
    "version": "1.5.0"
},
{
    "class": "com.mongodb.kafka.connect.MongoSourceConnector",
    "type": "source",
    "version": "1.5.0"
}...

]

when I use the following post I get the error:

Request:

{
"name": "mongodb-sink",
"config": {
    "connector.class": "com.mongodb.kafka.connect.MongoSinkConnector",
    "tasks.max": "1",
    "topics": "portalesMCor.db_portales.user",
    "connection.uri": "mongodb://tiastest.mti:27017",
    "database": "Big_Data",
    "collection": "users",
    "delete.on.null.values": false
}

}

Resposnse:

{
"error_code": 500,
"message": "Failed to find any class that implements Connector and which name matches com.mongodb.kafka.connect.MongoSinkConnector, available connectors are: PluginDesc{klass=class io.debezium.connector.db2.Db2Connector, name='io.debezium.connector.db2.Db2Connector', version='1.5.0.Final', encodedVersion=1.5.0.Final, type=source, typeName='source', location='file:/kafka/connect/debezium-connector-db2/'}, PluginDesc{klass=class io.debezium.connector.mongodb.MongoDbConnector, name='io.debezium.connector.mongodb.MongoDbConnector', version='1.5.0.Final', encodedVersion=1.5.0.Final, type=source, typeName='source', location='file:/kafka/connect/debezium-connector-mongodb/'}, PluginDesc{klass=class io.debezium.connector.mysql.MySqlConnector, name='io.debezium.connector.mysql.MySqlConnector', version='1.5.0.Final', encodedVersion=1.5.0.Final, type=source, typeName='source', location='file:/kafka/connect/debezium-connector-mysql/'}, PluginDesc{klass=class io.debezium.connector.oracle.OracleConnector, name='io.debezium.connector.oracle.OracleConnector', version='1.5.0.Final', encodedVersion=1.5.0.Final, type=source, typeName='source', location='file:/kafka/connect/debezium-connector-oracle/'}, PluginDesc{klass=class io.debezium.connector.postgresql.PostgresConnector, name='io.debezium.connector.postgresql.PostgresConnector', version='1.5.0.Final', encodedVersion=1.5.0.Final, type=source, typeName='source', location='file:/kafka/connect/debezium-connector-postgres/'}, PluginDesc{klass=class io.debezium.connector.sqlserver.SqlServerConnector, name='io.debezium.connector.sqlserver.SqlServerConnector', version='1.5.0.Final', encodedVersion=1.5.0.Final, type=source, typeName='source', location='file:/kafka/connect/debezium-connector-sqlserver/'}, PluginDesc{klass=class io.debezium.connector.vitess.VitessConnector, name='io.debezium.connector.vitess.VitessConnector', version='1.5.0.Final', encodedVersion=1.5.0.Final, type=source, typeName='source', location='file:/kafka/connect/debezium-connector-vitess/'}, PluginDesc{klass=class org.apache.kafka.connect.file.FileStreamSinkConnector, name='org.apache.kafka.connect.file.FileStreamSinkConnector', version='2.7.0', encodedVersion=2.7.0, type=sink, typeName='sink', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.file.FileStreamSourceConnector, name='org.apache.kafka.connect.file.FileStreamSourceConnector', version='2.7.0', encodedVersion=2.7.0, type=source, typeName='source', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.mirror.MirrorCheckpointConnector, name='org.apache.kafka.connect.mirror.MirrorCheckpointConnector', version='1', encodedVersion=1, type=source, typeName='source', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.mirror.MirrorHeartbeatConnector, name='org.apache.kafka.connect.mirror.MirrorHeartbeatConnector', version='1', encodedVersion=1, type=source, typeName='source', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.mirror.MirrorSourceConnector, name='org.apache.kafka.connect.mirror.MirrorSourceConnector', version='1', encodedVersion=1, type=source, typeName='source', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.tools.MockConnector, name='org.apache.kafka.connect.tools.MockConnector', version='2.7.0', encodedVersion=2.7.0, type=connector, typeName='connector', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.tools.MockSinkConnector, name='org.apache.kafka.connect.tools.MockSinkConnector', version='2.7.0', encodedVersion=2.7.0, type=sink, typeName='sink', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.tools.MockSourceConnector, name='org.apache.kafka.connect.tools.MockSourceConnector', version='2.7.0', encodedVersion=2.7.0, type=source, typeName='source', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.tools.SchemaSourceConnector, name='org.apache.kafka.connect.tools.SchemaSourceConnector', version='2.7.0', encodedVersion=2.7.0, type=source, typeName='source', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.tools.VerifiableSinkConnector, name='org.apache.kafka.connect.tools.VerifiableSinkConnector', version='2.7.0', encodedVersion=2.7.0, type=source, typeName='source', location='classpath'}, PluginDesc{klass=class org.apache.kafka.connect.tools.VerifiableSourceConnector, name='org.apache.kafka.connect.tools.VerifiableSourceConnector', version='2.7.0', encodedVersion=2.7.0, type=source, typeName='source', location='classpath'}"

}

Answer 1

I had a similar error when trying to use confluent's S3SinkConnector. Am posting my problem and solution here because this page shows up in the search results and there's a dearth of useful information out there.

Actually what happened is that I recompiled the connector after modifying its source code slightly because the original version didn't do exactly what I want. But then when I tried to start my connector I got the error message Failed to find any class that implements Connector and which name matches io.confluent.connect.s3.S3SinkConnector. This is even though the relevant .jar is in my plugin path and I could see with jar -tvf that the .jar contains io/confluent/connect/s3/S3SinkConnector.class.

I was running out of ideas so I tried moving the .jar file into the libs directory of my kafka installation, i.e. into /path/to/kafka_2.12-2.6.2/libs. Then I started getting a different error message:

java.lang.UnsupportedClassVersionError: io/confluent/connect/s3/S3SinkConnector has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

So the solution was to recompile the file with an older version of Java (specifically Java 8 using javac -release 8, as per these instructions.) Now it works!