--- schema_version: "1" id: ea04f7f5da1ab42220cc4558777c70a7452b50b42e51638474da50f94cb799b6 title: Troubleshooting Apache Kafka Connector 4.14 collection: mulesoft version: current locale: en-us portal_url: https://docs.salesforce.com/mulesoft/current/en-us/kafka-connector/4.14/kafka-connector-troubleshooting.md canonical_url: https://docs.mulesoft.com/kafka-connector/4.14/kafka-connector-troubleshooting source_site: docs.mulesoft.com content_type: documentation content_hash: b08d55fcf74afea4711e92b845b875baf79120f4c12fba58773d0ba8e63f681d description: MuleSoft Documentation Site release: "4.14" latest: false --- --- product: Apache Kafka Connector version: 4.14 --- # Troubleshooting Apache Kafka Connector 4.14 > For the full documentation index, see: https://docs.mulesoft.com/llms.txt To troubleshoot Anypoint Connector for Apache Kafka (Apache Kafka Connector), become familiar with the information about interpreting commonly thrown exception messages. ## Enable SSL Logging Enable SSL logs to investigate an issue related to TLS communications. Set your SSL log level depending on your required level of detail: 1. Enable only SSL log details: `javax.net.debug=ssl` 2. Enable only handshaking details. (The handshake protocol is a series of messages exchanged over the record protocol.) `javax.net.debug=ssl:handshake` 3. Enable handshaking details and SSL details at the same time: `javax.net.debug=ssl, handshake` 4. Enable the dumping of all details and traffic data: `javax.net.debug=all` > [!NOTE] This option is very verbose and under normal circumstances is not necessary. > [!WARNING] SSL logging results in a performance impact for HTTPS or other TLS connections. Enable > SSL logging only to troubleshoot a specific issue and do not enable it for extended periods. SSL > logging produces a significant amount of log messages and can inundate your log file if it is left > enabled and unattended. To enable SSL logs: Set the debug parameter as an argument in the runtime configuration for the application. 1. In Studio, right-click on the project and select **Run > Run Configurations**. 2. Go to the **Arguments** tab and add `-M-Djavax.net.debug=ssl` in the **VM arguments** section. ## Enable Verbose Exception Logging Enable verbose exception logs to show a complete stack trace of the error instead of the default truncated output: 1. In Studio, right-click on the project and select **Run > Run Configurations**. 2. Go to the **Arguments** tab and append the arguments in the **VM arguments** section to add the `mule.verbose.exceptions` property. For example: `-XX:PermSize=128M -XX:MaxPermSize=256M -Dmule.verbose.exceptions=true` ## Enable Verbose Logging To get a better understanding of why an application’s interaction with Kafka Connector is failing, temporarily enable verbose logging for the connector. Remember to always disable enhanced verbosity after troubleshooting, because it can affect your Mule application’s performance. To enable verbose logging in the configuration file: 1. Access Anypoint Studio and navigate to the **Package Explorer** view. 2. Open your application’s project name. 3. Open the `src/main/resources` folder. 4. Open the `log4j2.xml` file inside the folder. 5. Add an `` tag inside the `` tag: ```xml ... ... ``` 6. Save your application changes. 7. Click the project name in **Package Explorer** and then click **Run** > **Run As** > **Mule Application**. ## Enable FIPS Mode Enable FIPS mode by setting the `com.mulesoft.connectors.allow-registration-of-sasl-security-provider-in-fips=true` flag to true. This adds the `com.sun.security.sasl.Provider` security provider in the FIPS environment. ## Failed to Load SSL Keystore When the Kafka Connector configurations fail to load the required truststore files from the classpath, you receive the following error: ```text org.mule.runtime.api.connection.ConnectionException: Failed to load SSL keystore ``` The Kafka Connector configurations bundled with a dependency fail to establish connections even when the required truststore files are available in the classpath. To resolve this error: Add the required truststore files to the main application that uses the Kafka Connector configurations. ## Troubleshooting clientDNSLookUp Property Since Kafka Connector version 3.0.0, the default value for the **DNS Lookup** field was removed to keep the connector backwards compatible. Kafka Connector keeps the same values as the previous version, but now each value corresponds to the following properties:
ValueProperty

DEFAULT

use_all_dns_ips

USE_ALL_DNS_IPS

use_all_dns_ips

RESOLVE_CANONICAL_BOOTSTRAP_SERVERS_ONLY

resolve_canonical_bootstrap_servers_only

## Troubleshooting Publishing Null Values When the **Publish** operation receives null as input, the operation publishes an empty byte array. To avoid this issue, the connector enables you to set the `mule.kafka.publish.useNull` boolean system property. - When set to `true`, the connector publishes a message with null as a value. - When set to `false` or not set at all, the connector publishes a message with an empty byte array value. For further information on how to configure properties, refer to the [Use system properties](https://docs.mulesoft.com/mule-runtime/latest/mule-app-properties-system) ## Understand Commonly Thrown Exceptions Here is a list of commonly thrown exception messages and how to interpret them: - KAFKA:ALREADY\_COMMITTED A commit fails because the commit is already performed. - KAFKA:AUTHENTICATION\_ERROR(SECURITY) An authentication error is thrown. - KAFKA:AUTHORIZATION\_ERROR(CLIENT\_SECURITY) An authorization error occurred due to the client configuration or permissions. - KAFKA:COMMIT\_FAILED A commit fails with an unrecoverable error. - KAFKA:CONNECTIVITY Either a connection could not be established or there is a connectivity error. - KAFKA:ILLEGAL\_STATE The consumer is not subscribed to any topics, and no manually assigned partitions are set to consume from. - KAFKA:INPUT\_TOO\_LARGE The input is too large for the broker. - KAFKA:INVALID\_ACK\_MODE An acknowledgement (ACK) or negative acknowledgement (NACK) operation is run over a consumer that is not in \`MANUAL\` mode. - KAFKA:INVALID\_CONFIGURATION An invalid configuration value is set for the consumer or the producer. - KAFKA:INVALID\_CONNECTION The referenced connection is invalid. - KAFKA:INVALID\_INPUT The parameters set for the operation are incorrect. - KAFKA:INVALID\_OFFSET The partition number set for the operation is less than \`0\`, is above the number of partitions, or is an invalid value. - KAFKA:INVALID\_TOPIC The topic selected for the operation is invalid, and there is no automatic generation of said topic. This might also imply an invalid character in the topic name. - KAFKA:INVALID\_TOPIC\_PARTITION The topic partition combination selected for the operation is invalid, and there is no automatic generation of topics. This might also imply an invalid character in the topic name, or a non-existing partition. - KAFKA:NO\_POLL\_MADE No poll was made. - KAFKA:NOT\_FOUND For consume operations, the poll does not bring any records for the configured timeouts. - KAFKA:OUT\_OF\_RANGE There is no reset policy defined, and the offsets for these partitions are either larger or smaller than the range of offsets the server has for the given partition. - KAFKA:PREVIOUS\_ASSIGNATION subscribe() is called previously with topics or pattern without a subsequent call to unsubscribe(). - KAFKA:PRODUCER\_FENCED Another producer with the same \`transactional.id\` is active. - KAFKA:RETRY\_EXHAUSTED The maximum number of retries for the operation is reached. - KAFKA:SESSION\_NOT\_FOUND No associated session is found when executing an operation. - KAFKA:TIMEOUT A specific request takes longer than the configuration timeout values. ## See Also - [Introduction to Anypoint Connectors](https://docs.mulesoft.com/connectors/introduction/introduction-to-anypoint-connectors) - [Apache Kafka Connector Reference](https://docs.mulesoft.com/kafka-connector/4.14/kafka-connector-reference) - [Salesforce Help](https://help.salesforce.com) - [Salesforce Help](https://help.salesforce.com) - [Known Issues](https://help.salesforce.com/s/issues)