Known Issues in Apache Kafka

Learn about the known issues in Kafka, the impact or changes to the functionality, and the workaround.

OPSAPS-59553: SMM's bootstrap server config should be updated based on Kafka's listeners: SMM does not show any metrics for Kafka or Kafka Connect when multiple listeners are set in Kafka.; Workaround: SMM cannot identify multiple listeners and still points to bootstrap server using the default broker port (9093 for SASL_SSL). You would have to override bootstrap server URL (hostname:port as set in the listeners for broker) in the following path:
Cloudera Manager > SMM > Configuration > Streams Messaging Manager Rest Admin Server Advanced Configuration Snippet (Safety Valve) for streams-messaging-manager.yaml > Save Changes > Restart SMM.
Topics created with the kafka-topics tool are only accessible by the user who created them when the deprecated --zookeeper option is used: By default all created topics are secured. However, when topic creation and deletion is done with the kafka-topics tool using the --zookeeper option, the tool talks directly to Zookeeper. Because security is the responsibility of ZooKeeper authorization and authentication, Kafka cannot prevent users from making ZooKeeper changes. As a result, if the --zookeeper option is used, only the user who created the topic will be able to carry out administrative actions on it. In this scenario Kafka will not have permissions to perform tasks on topics created this way.; Use kafka-topics with the --bootstrap-server option that does not require direct access to Zookeeper.

Certain Kafka command line tools require direct access to Zookeeper: The following command line tools talk directly to ZooKeeper and therefore are not secured via Kafka:

kafka-configs

kafka-reassign-partitions; None

The offsets.topic.replication.factor property must be less than or equal to the number of live brokers: The offsets.topic.replication.factor broker configuration is now enforced upon auto topic creation. Internal auto topic creation will fail with a GROUP_COORDINATOR_NOT_AVAILABLE error until the cluster size meets this replication factor requirement.; None

Requests fail when sending to a nonexistent topic with auto.create.topics.enable set to true: The first few produce requests fail when sending to a nonexistent topic with auto.create.topics.enable set to true.; Increase the number of retries in the producer configuration setting retries.

Custom Kerberos principal names cannot be used for kerberized ZooKeeper and Kafka instances: When using ZooKeeper authentication and a custom Kerberos principal, Kerberos-enabled Kafka does not start. You must disable ZooKeeper authentication for Kafka or use the default Kerberos principals for ZooKeeper and Kafka.; None

Performance degradation when SSL Is enabled: In some configuration scenarios, significant performance degradation can occur when SSL is enabled. The impact varies depending on your CPU, JVM version, Kafka configuration, and message size. Consumers are typically more affected than producers.; Configure brokers and clients with ssl.secure.random.implementation = SHA1PRNG. It often reduces this degradation drastically, but its effect is CPU and JVM dependent.

OPSAPS-43236: Kafka garbage collection logs are written to the process directory: By default Kafka garbage collection logs are written to the agent process directory. Changing the default path for these log files is currently unsupported.; None

OPSAPS-59031: Kafka cannot start if configuration is added to the Kafka Broker Advanced Configuration Snippet (Safety Valve) for ssl.properties: The Kafka Broker Advanced Configuration Snippet (Safety Valve) for ssl.properties configuration snippet does not correctly override configuration. As a result, Kafka may not start if TLS/SSL related configuration overrides are added to the this configuration snippet.; Use the Kafka Broker Advanced Configuration Snippet (Safety Valve) for kafka.properties configuration snippet instead to override SSL related properties.

OPSAPS-58492: Automatic Ranger service creation for Kafka is incomplete: When a new resource based service is created for Kafka in Ranger, the cruisecontrol user is not added to the policy set. This prevents Cruise Control from working properly.; Manually add the cruisecontrol user to the Kafka resource based service in Ranger.

CDPD-11775: Kafka Connect does not start due to occupied ports: By default the Kafka Connect role binds to ports that are in the ephemeral range. As many other services can use port 0 and can bind to any port in the ephemeral range, it can happen that the default Kafka Connect ports become occupied. In a case like this, the Kafka Connect role will not start.; Configure the Kafka Connect rest port, Kafka Connect secure rest port, and Jetty Metrics port to expose JMX Json Kafka properties in Cloudera Manager. Cloudera recommends that you use the following ports:

Kafka Connect rest port: 28083

Kafka Connect secure rest port: 28085

Jetty Metrics port to expose JMX Json: 28084

Additionally, if you are using SMM to monitor Kafka Connect, you must also configure the Kafka Connect Rest PortStreams Messaging Manager property. The port configured in this property must match the port configured for the Kafka Connect role.

Unsupported Features

: The following Kafka features are not supported in Cloudera Data Platform:

Only Java and .Net based clients are supported. Clients developed with C, C++, Python, and other languages are currently not supported.

The Kafka default authorizer is not supported. This includes setting ACLs and all related APIs, broker functionality, and command-line tools.

Limitations

Collection of Partition Level Metrics May Cause Cloudera Manager’s Performance to Degrade: If the Kafka service operates with a large number of partitions, collection of partition level metrics may cause Cloudera Manager's performance to degrade.

If you are observing performance degradation and your cluster is operating with a high number of partitions, you can choose to disable the collection of partition level metrics.
important
If you are using SMM to monitor Kafka or Cruise Control for rebalancing Kafka partitions, be aware that both SMM and Cruise Control rely on partition level metrics. If partition level metric collection is disabled, SMM will not be able to display information about partitions. In addition, Cruise Control will not operate properly.

Complete the following steps to turn off the collection of partition level metrics:

Obtain the Kafka service name:

In Cloudera Manager, Select the Kafka service.

Select any available chart, and select Open in Chart Builder from the configuration icon drop-down.

Find $SERVICENAME= near the top of the display.
The Kafka service name is the value of $SERVICENAME.

Turn off the collection of partition level metrics:

Go to Hosts > Hosts Configuration.

Find and configure the Cloudera Manager Agent Monitoring Advanced Configuration Snippet (Safety Valve) configuration property.
Enter the following to turn off the collection of partition level metrics:
[KAFKA_SERVICE_NAME]_feature_send_broker_topic_partition_entity_update_enabled=false
Replace [KAFKA_SERVICE_NAME] with the service name of Kafka obtained in step 1. The service name should always be in lower case.

Click Save Changes.