Jdbc.sink.error An unexpected error occurred: java.lang.NoClassDefFoundError: Could not initialize class io.confluent.connect.jdbc.sink.JdbcSinkConfig

Question

Confluent platform add sink connector image

Trying add sink connector in confluent platform it give me errors

The connector install manually -- confluent-hub install confluentinc/kafka-connect-jdbc:10.7.6

{
"class": "io.confluent.connect.jdbc.JdbcSinkConnector",
"type": "sink",
"version": "10.7.6"
},
{
"class": "io.confluent.connect.jdbc.JdbcSourceConnector",
"type": "source",
"version": "10.7.6"
}

source connector working properly , confluent UI did not give any error.

I am using locally Confluent 10.7.4.--confluent version v3.2.1

Java version-- openjdk 11.0.22 2024-01-16 OpenJDK Runtime Environment OpenLogic-OpenJDK (build 11.0.22+7-adhoc.admin.jdk11u) OpenJDK 64-Bit Server VM OpenLogic-OpenJDK (build 11.0.22+7-adhoc.admin.jdk11u, mixed mode)

Error in Connect log

ERROR Uncaught exception in REST call to /connector plugins/io.confluent.connect.jdbc.JdbcSinkConnector/config/validate (org.apache.kafka.connect.runtime.rest.errors.ConnectExceptionMapper:64)
java.util.concurrent.ExecutionException: java.lang.ExceptionInInitializerError
at org.apache.kafka.connect.util.ConvertingFutureCallback.result(ConvertingFutureCallback.java:123)
at org.apache.kafka.connect.util.ConvertingFutureCallback.get(ConvertingFutureCallback.java:115)
at org.apache.kafka.connect.runtime.rest.resources.ConnectorPluginsResource.validateConfigs(ConnectorPluginsResource.java:109)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:134)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:177)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$TypeOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:219)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:81)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:475)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:397)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:81)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:255)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:248)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:244)
at org.glassfish.jersey.internal.Errors.process(Errors.java:292)
at org.glassfish.jersey.internal.Errors.process(Errors.java:274)
at org.glassfish.jersey.internal.Errors.process(Errors.java:244)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:265)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:234)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:684)
at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:394)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:346)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:358)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:311)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:205)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:554)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:505)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:234)
at org.eclipse.jetty.server.handler.StatisticsHandler.handle(StatisticsHandler.java:181)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
at org.eclipse.jetty.server.Server.handle(Server.java:516)
at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487)
at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
at java.base/java.lang.Thread.run(Thread.java:829)

Caused by: java.lang.ExceptionInInitializerError
at io.confluent.connect.jdbc.JdbcSinkConnector.config(JdbcSinkConnector.java:70)
at org.apache.kafka.connect.runtime.AbstractHerder.validateConnectorConfig(AbstractHerder.java:580)
at org.apache.kafka.connect.runtime.AbstractHerder.lambda$validateConnectorConfig$6(AbstractHerder.java:470)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
... 1 more

Caused by: org.apache.kafka.common.config.ConfigException: Invalid value insert for configuration insert.mode: Invalid enumerator
at io.confluent.connect.jdbc.sink.JdbcSinkConfig$EnumValidator.ensureValid(JdbcSinkConfig.java:658)
at org.apache.kafka.common.config.ConfigDef$ConfigKey.<init>(ConfigDef.java:1270)
at org.apache.kafka.common.config.ConfigDef.define(ConfigDef.java:159)
at org.apache.kafka.common.config.ConfigDef.define(ConfigDef.java:179)
at org.apache.kafka.common.config.ConfigDef.define(ConfigDef.java:218)
at io.confluent.connect.jdbc.sink.JdbcSinkConfig.<clinit>(JdbcSinkConfig.java:362)
... 8 more

What is the problem ?

Answer 1

This is a bug in the Confluent JDBC Connector. It fails to initialise itself if it is being run in the Turkish locale.

The bug is in this method:

    public static <E> EnumValidator in(E[] enumerators) {
      final List<String> canonicalValues = new ArrayList<>(enumerators.length);
      final Set<String> validValues = new HashSet<>(enumerators.length * 2);
      for (E e : enumerators) {
        canonicalValues.add(e.toString().toLowerCase());
        validValues.add(e.toString().toUpperCase());
        validValues.add(e.toString().toLowerCase());
      }
      return new EnumValidator(canonicalValues, validValues);
    }

The problem is that the calls to .toLowerCase() and .toUpperCase() do not specify the locale in which they are performing case conversion. So the conversion happens in the default locale. For the insert.mode configuration default, the valid values are those that are the names of the InsertMode enum (INSERT, UPSERT and UPDATE), plus the lower-case values of these. In the Turkish locale, these are ınsert, upsert and update.

The JdbcSinkConfig class contains some functionality to check that all default values for configuration are valid. The insert.mode parameter is one of the configuration parameters whose value is checked. The default value for insert.mode is insert. Of course, in the Turkish locale, this isn't one of the valid values, hence an exception is thrown.

If it is an option for you to use an English locale instead of a Turkish locale, then I would expect things to work. If not, you are waiting on Confluent to fix this bug. I've reported this bug on their GitHub repo here.