Known Issues in Kafka

CDPD-60862: Rolling restart fails during ZDU when DDL operations are in progress

During a Zero Downtime Upgrade (ZDU), the rolling restart of services that support Data Definition Language (DDL) statements might fail if DDL operations are in progress during the upgrade. As a result, ensure that you do not run DDL statements during ZDU.

The following services support DDL statements:

Impala
Hive – using HiveQL
Spark – using SparkSQL
HBase
Phoenix
Kafka

Data Manipulation Lanaguage (DML) statements are not impacted and can be used during ZDU. Following the successful upgrade, you can resume running DDL statements.

None. Cloudera recommends modifying applications to not use DDL statements for the duration of the upgrade. If the upgrade is already in progress, and you have experienced a service failure, you can remove the DDLs in-flight and resume the upgrade from the point of failure.

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.

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.

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.

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

RANGER-3809: Idempotent Kafka producer fails to initialize due to an authorization failure

Kafka producers that have idempotence enabled require the Idempotent Write permission to be set on the cluster resource in Ranger. If permission is not given, the client fails to initialize and an error similar to the following is thrown:

org.apache.kafka.common.KafkaException: Cannot execute transactional method because we are in an error state
             at org.apache.kafka.clients.producer.internals.TransactionManager.maybeFailWithError(TransactionManager.java:1125)
             at org.apache.kafka.clients.producer.internals.TransactionManager.maybeAddPartition(TransactionManager.java:442)
             at org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:1000)
             at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:914)
             at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:800)
             .
             .
             .
             Caused by: org.apache.kafka.common.errors.ClusterAuthorizationException: Cluster authorization failed.

Idempotence is enabled by default for clients in Kafka 3.0.1, 3.1.1, and any version after 3.1.1. This means that any client updated to 3.0.1, 3.1.1, or any version after 3.1.1 is affected by this issue.

This issue has two workarounds, do either of the following:

Explicitly disable idempotence for the producers. This can be done by setting enable.idempotence to false.
Update your policies in Ranger and ensure that producers have Idempotent Write permission on the cluster resource.

CDPD-49304: AvroConverter does not support composite default values

AvroConverter cannot handle schemas containing a STRUCT type default value.

None.

DBZ-4990: The Debezium Db2 Source connector does not support schema evolution

The Debezium Db2 Source connector does not support the evolution (updates) of schemas. In addition, schema change events are not emitted to the schema change topic if there is a change in the schema of a table that is in capture mode. For more information, see DBZ-4990.

None.

CFM-3532: The Stateless NiFi Source, Stateless NiFi Sink, and HDFS Stateless Sink connectors cannot use Snappy compression

This issue only affects Stateless NiFi Source and Sink connectors if the connector is running a dataflow that uses a processor that uses Hadoop libraries and is configured to use Snappy compression. The HDFS Stateless Sink connector is only affected if the Compression Codec or

Compression Codec
              for Parquet

properties are set to SNAPPY.

If you are affected by this issue, errors similar to the following will be present in the logs.

Failed to write to HDFS due to java.lang.UnsatisfiedLinkError: org.apache.hadoop.util.NativeCodeLoader.buildSupportsSnappy()

Failed to write to HDFS due to java.lang.RuntimeException: native snappy library not available: this version of libhadoop was built without snappy support.

Download and deploy missing libraries.

Create the /opt/nativelibs directory.
```
mkdir /opt/nativelibs
```
Change the owner to kafka.
```
chown kafka:kafka /opt/nativelibs
```
Locate the directory containing the Hadoop native libraries and copy its contents to the directory you created.
```
cp /opt/cloudera/parcels/CDH/lib/hadoop/lib/native/* /opt/nativelibs
```
Verify that libsnappy.so was copied to the directory you created.

Remove the following from /opt/nativelibs.

libhadoop.a
                 libhadoop.so
                 libhadoop.so.1.0.0

Run the following command.
```
hadoop version
```
The command returns the Hadoop version running in the cluster. Note down the first three digits in the version.
Go to https://archive.apache.org/dist/hadoop/common/ and download the Hadoop version that matches the first three digits of the version running in the cluster.
For example, if your Hadoop version is 3.1.1.7.1.9.0-296, then you need to download Hadoop 3.1.1.
Extract the downloaded archive.
Copy the following libraries from the downloaded archive to /opt/nativelibs on the cluster host.
```
libhadoop.a
                 libhadoop.so.1.0.0
```
The libraries are located in hadoop-[***VERSION***]/lib/native.
Create a symlink named libhadoop.so and point it to /opt/nativelibs/libhadoop.so.1.0.0.
```
ln -s /opt/nativelibs/libhadoop.so.1.0.0 /opt/nativelibs/libhadoop.so
```
Change the owner of every entry within /opt/nativelibs to kafka.
```
chown -h kafka:kafka /opt/nativelibs/*
```
In Cloudera Manager, go to Kafka service > Configuration.
Add the following key-value pair to Kafka Connect Environment Advanced Configuration Snippet (Safety Valve).
- Key: LD_LIBRARY_PATH
- Value: /opt/nativelibs
Click Save Changes.
Restart the Kafka service.

OPSAPS-69317: Kafka Connect Rolling Restart Check fails if SSL Client authentication is required

The rolling restart action does not work in Kafka Connect when the ssl.client.auth option is set to required. The health check fails with a timeout which blocks restarting the subsequent Kafka Connect instances.

You can set ssl.client.auth to requested instead of required and initiate a rolling restart again. Alternatively, you can perform the rolling restart manually by restarting the Kafka Connect instances one-by-one and checking periodically whether the service endpoint is available before starting the next one.

Known Issues in Kafka

Known issues identified in Cloudera Runtime 7.1.9 SP1 CHF 9

Known issues identified before Cloudera Runtime 7.1.9 SP1 CHF 9