Known Issues

Summarizes known issues for this release.

JDK limitation

JDK 8u271, JDK 8u281, and JDK 8u291 may cause socket leak issues in NiFi due to JDK-8245417 and JDK-8256818. Pay attention to the build version of your JDK because some later builds are fixed as described in JDK-8256818.

Workaround: Consider using a more recent version of the JDK like 8u282, or builds of the JDK where the issue is fixed.

ReplaceText with multiple concurrency tasks can result in data corruption

ReplaceText, when scheduled to run with multiple Concurrent Tasks, and using a Replacement Strategy of "Regular Expression" or "Literal Replace" can result in content being corrupted.

The issue is far more likely to occur with multiple Concurrent Tasks, but it may be possible to trigger when using a single Concurrent Task.

To get the fix for this issue, file a support case through the Cloudera portal.

NiFi Registry start issue

When you upgrade CFM, NiFi Registry might fail during the start with the following error message:

Caused by: org.xml.sax.SAXParseException: cvc-complex-type.2.4.b: The content of element 'providers' is not complete. One of '{eventHookProvider, extensionBundlePersistenceProvider}' is expected.

To resolve this issue:

1. Go to the NiFi Registry Advanced Configuration Snippet (Safety Valve) section in Cloudera Manager for staging/providers.xml.
2. Click View as XML and paste the following configuration in the template:

   <property>
   <name>xml.providers.extensionBundlePersistenceProvider.file-bundle-provider.class</name>
   <value>org.apache.nifi.registry.provider.extension.FileSystemBundlePersistenceProvider</value>
   </property>
   <property>
   <name>xml.providers.extensionBundlePersistenceProvider.file-bundle-provider.property.Extension Bundle Storage Directory</name>
   <value>${nifi.registry.working.directory}/extension_bundles</value>
   </property>

NiFi start issue

If the master key password or LDAP manager password contains a $ character, Cloudera Manager will fail to start NiFi. The following image shows the error messsage:

To resolve, remove or replace the $ in the password.

Base cluster and compute cluster names must not have white space

When you create your base cluster or compute cluster, ensure that the cluster name does not contain any white space.

Ranger audits for NiFi and NiFi Registry

After you install NiFi and NiFi Registry, complete the following steps to ensure that Ranger audits are stored correctly in HDFS:

NiFi:

1. Go to the NiFi Actions menu and trigger the Create Ranger NiFi Plugin Audit Directory service command.
2. Go to the NiFi Configuration page and set "xml.authorizers.authorizer.ranger-provider.classpath" = "${CONF_DIR}/hadoop-conf".
3. Restart NiFi.

NiFi Registry:

1. NiFi Registry must be installed with a NiFi dependency. Only in this case, the NiFi Registry config directory will contain the hadoop-conf directory with related HDFS configurations. Check that this directory is available.
2. Connect to the host with NiFi Registry and run the following HDFS commands:

   hadoop fs -mkdir /ranger/audit/nifi-registry
   hadoop fs -chown nifiregistry:nifiregistry /ranger/audit/nifi-registry
   hadoop fs -chmod 755 /ranger/audit/nifi-registry

3. Go to Cloudera Manager UI on the NiFi Registry Configiuration page and set "xml.authorizers.authorizer.ranger-provider.classpath" = "${CONF_DIR}/hadoop-conf".
4. Restart NiFi Registry.

Ranger High Availability

If you have multiple instances of the Ranger Admin service and if the ranger_rest_url parameter contains a comma separated list of URLs (i.e. the Ranger instances are not behind a load balancer), then NiFi and NiFi Registry will not start and the following error appears in Cloudera Manager:

Traceback (most recent call last):
File "/var/run/cloudera-scm-agent/process/1546471613-nifiregistry-NIFI_REGISTRY_SERVER/scripts/ranger.py", line 683, in <module>
main()
File "/var/run/cloudera-scm-agent/process/1546471613-nifiregistry-NIFI_REGISTRY_SERVER/scripts/ranger.py", line 633, in main
keytab=args.keytab, principal=args.principal)
File "/var/run/cloudera-scm-agent/process/1546471613-nifiregistry-NIFI_REGISTRY_SERVER/scripts/ranger.py", line 302, in create_ranger_repository
_create()
File "/var/run/cloudera-scm-agent/process/1546471613-nifiregistry-NIFI_REGISTRY_SERVER/scripts/ranger.py", line 291, in _create
ranger_service_name, code, out))
Exception: Failed to create ranger repository 'Lower Environment_nifiregistry', response code is '404', output is ''.

To resolve, place the Ranger instances behind a load balancer. Alternatively, create a support case on the Cloudera Support portal.