Cloudera Docs

Known Issues in Apache Kafka

This topic describes known issues and unsupported features for using Kafka in this release of Cloudera Runtime.

Known Issues

Topics created with the kafka-topics tool might not be secured when the deprecated --zookeeper option is used

Topics that are created and deleted via Kafka are secured (for example, auto created topics). 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. Anyone with access to ZooKeeper can create and delete topics. They will not be able to describe, read, or write to the topics even if they can create them.

Workaround: 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
Workaround: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.

Workaround: 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.

Workaround: 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.

Workaround: None.
Performance degradation when SSL Is enabled

Significant performance degradation can occur when SSL is enabled. The impact varies depending on your CPU, JVM version, and message size. Consumers are typically more affected than producers.

Workaround: Configure brokers and clients with ssl.secure.random.implementation = SHA1PRNG. It often reduces this degradation drastically, but its effect is CPU and JVM dependent.
Apache JIRA: KAFKA-2561
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.

Workaround: None.
OPSAPS-57113: The Kafka Broker Advanced Configuration Snippet (Safety Valve) for ssl.properties does not propagate configurations correctly.

If the Kafka Broker Advanced Configuration Snippet (Safety Valve) for ssl.properties property contains configuration that has dollar signs, the configuration is not propagated to Kafka brokers correctly.

Workaround:None.

Unsupported Features

The following Kafka features are not supported in Cloudera Data Platform:
  • Only Java based clients are supported. Clients developed with C, C++, Python, .NET and other languages are currently not supported.
  • Kafka Connect is not supported. NiFi is a proven solution for batch and real time data loading that complement Kafka's message broker capability. For more information, see Cloudera Flow Management.
  • The Kafka default authorizer is not supported. This includes setting ACLs and all related APIs, broker functionality, and command-line tools.