Known Issues in Hue

This topic describes known issues and workarounds for using Hue in this release of Cloudera Runtime.

Downloading Impala query results containing special characters in CSV format fails with ASCII codec error

In CDP, Hue is compatible with Python 2.7.x, but the Tablib library for Hue has been upgraded from 0.10.x to 0.14.x, which is generally used with the Python 3 release. If you try to download Impala query results having special characters in the result set in a CSV format, then the download may fail with the ASCII unicode decode error.

To fix this issue, downgrade the Tablib library to 0.12.x.

1. SSH into the Hue server host.
2. Change directory to the following:

   cd /opt/cloudera/parcels/CDH-7.x/lib/

3. Back up the hue directory:

   cp -R hue hue_orginal

4. Change to the hue directory:

   cd hue

5. Install the Wheel package using pip:

   ./build/env/bin/pip install wheel

   The Wheel package is used to avoid recompiling your software during every install.

6. Install the Python Setuptools package for Hue as follows:

   ./build/env/bin/pip setuptools==44.1.0

7. Install Tablib version 0.12.1 as follows:

   ./build/env/bin/pip install tablib==0.12.1

8. Go to Cloudera Manager and restart the Hue service.

CDPD-18959: Due to tablib upgrade for Hue in CDP from 0.10.x to 0.14.x release which is generally used for Python3 release, the CSV download has a special character in the dataset which fails with the error message "UnicodeDecodeError: 'ascii' codec can't decode byte 0xef in position 8: ordinal not in range(128)"

Workaround:

• cd /opt/cloudera/parcels/CDH/lib/
• Backup the hue folder cp -R hue hue_orgi
• cd hue
• Install python packages via pippip install wheel
• Install python packages for Hue
  • ./build/env/bin/pip install wheel.
  • /build/env/bin/pip setuptools==44.1.0
  • ./build/env/bin/pip install tablib==0.12.1
• Restart Hue and and check again

Impala SELECT table query fails with UTF-8 codec error

Hue cannot handle columns containing non-UTF8 data. As a result, you may see the following error while queying tables from the Impala editor in Hue: 'utf8' codec can't decode byte 0x91 in position 6: invalid start byte.

To resolve this issue, contact Cloudera Support to apply the following software patch: ENGESC-3457.

Hue Importer is not supported in the Data Engineering template

When you create a Data Hub cluster using the Data Engineering template, the Importer application is not supported in Hue.

Hue Importer is not supported in the Data Engineering template

When you create a Data Hub cluster using the Data Engineering template, the Importer application is not supported in Hue:

CDPD-3501: Hue-Atlas configuration information is missing on Data Mart clusters.

Problem: The configuration file hive-conf%2Fatlas-application.properties is missing on Data Mart clusters because Apache Hive is not installed. This properties file is needed for the Hue integration with Apache Atlas.

Workaround:

1. Log in to the CDP web interface and navigate to the Data Hub service.
2. On the Data Hub Clusters page, click the Data Mart cluster you want to work on.
3. On the Data Mart cluster page, click the URL link to Cloudera Manager Info:
   
   
4. On the Home page of Cloudera Manager, click the cluster name under Compute Clusters:
   
   
5. In the cluster page in the Status column under Compute Cluster, Cloudera Runtime, click the link to Hue:
   
   
6. On the Hue page, click the Configuration tab to view the configuration properties for Hue.
7. In the search text box, type safety and press Enter to locate the Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini, which appears at the top of the configuration parameters list.
8. Append the following configuration information to the existing configuration information in the Safety Valve and click Save Changes:

   [metadata]
   [[catalog]]
   interface=atlas
   api_url=http://master0.cloudera.site:21000/api/atlas/
   kerberos_enabled=true

9. Restart the Hue service for the configuration change to take effect.

BalancerMember worker hostname too long error

You may see the following error message while starting the Hue Load Balancer:

BalancerMember worker hostname (xxx-xxxxxxxx-xxxxxxxxxxx-xxxxxxx.xxxxxx-xxxxxx-xxxxxx.example.site) too long.

Cloudera Manager displays this error when you create a Data Hub cluster using the Data Engineering template and the Hue Load Balancer worker node name has exceeded 64 characters. In a CDP Public Cloud deployment, the system automatically generates the Load Balancer worker node name through AWS or Azure.

For example, if you specify cdp-123456-scalecluster as the cluster name, CDP creates cdp-123456-scalecluster-master2.repro-aw.a123-4a5b.example.site as the worker node name.

Workaround: Specify a shorter cluster name while creating a Data Hub cluster so that the final worker node name does not cross 64 characters.

For example, cdp-123456-scale.

Hue limitation after upgrading from CDH to CDP Data Center

The hive.server2.parallel.ops.in.session configuration property changes from TRUE to FALSE after upgrading from CDH to CDP Data Center. Current versions of Hue are compatible with this property change; however, if you still would like to use an earlier version of Hue that was not compatible with this property being FALSE and shared a single JDBC connection to issue queries concurrently, the connection will no longer work after upgrading.