Known Issues in Hue

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

OPSAPS-69659: Hue service fails on restart with "Unable to find psycopg2 2.5.4" error

Hue service fails to restart and you see the following error: Unable to find psycopg2 2.5.4. This could be because you have installed Python in a non-default location and Hue is unable to locate the psycopg2 PostgreSQL database adapter.

You must specify the path where you have installed Python in the PYTHONPATH property in the Hue Advanced Configuration Snippet using Cloudera Manager.

1. Log in to Cloudera Manager as an Administrator.
2. Go to Clusters > Hue > Configurations and add the following key and value in the Hue Service Environment Advanced Configuration Snippet (Safety Valve) field:

   Key: PYTHONPATH

   Value: [***PYTHON-PATH***]

   Replace [***PYTHON-PATH***] with the actual location where you have installed Python. For example, /opt/cloudera/parcels/CDH/lib/hue/build/env/lib/python3.8/site-packages

3. Click Save Changes.
4. Restart the Hue service.

CDPD-58978: Batch query execution using Hue fails with Kerberos error

When you run Impala queries in a batch mode, you enounter failures with a Kerberos error even if the keytab is configured correctly. This is because submitting Impala, Sqoop, Pig, or pyspark queries in a batch mode launches a shell script Oozie job from Hue and this is not supported on a secure cluster.

There is no workaround. You can submit the queries individually.

CDPD-59677: Unable to view Phoenix tables on the left assist in Hue

On clusters secured with Knox, you may not be able to see Phoenix tables on the left assist that are present under the default database (that is, an empty('') database).

None.

CDPD-58142: A query is not pre-populated in the Hue editor after clicking on the Re Execute button

When you click Re Execute to rerun a query from the Job Browser > Queries > Query Details page, the query does not get populated on the Hue editor, as expected.

None.

CDPD-54376: Clicking the home button on the File Browser page redirects to HDFS user directory

When you are previewing a file on any supported filesystem, such as S3 or ABFS, and you click on the Home button, you are redirected to the HDFS user home directory instead of the user home directory on the said filesystem.

None.

CDPD-41306: pip3.8 freeze command does not work and results into an error

You see the /usr/lib/hue/build/env/bin/python: No such file or directory error when you run the following command:

build/env/bin/pip3.8 freeze

Run the freeze command as follows by specifying the paths of python3.8 and pip3.8:

/opt/cloudera/parcels/CDH/lib/hue/build/env/bin/python3.8 /opt/cloudera/parcels/CDH/lib/hue/build/env/bin/pip3.8 freeze

CDPD-43293: Unable to import Impala table using Importer

Creating Impala tables using the Hue Importer may fail.

If you have both Hive and Impala services installed on your cluster, then you can import the table using by selecting the Hive dialect from Tables > Sources.

If only Impala service is installed on your cluster, then go to Cloudera Manager > Clusters > Hue > Configurations and add the following line in the Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini field:

[beeswax]
max_number_of_sessions=1

CDPD-41136: Importing files from the local workstation is disabled by default

Cloudera has disabled the functionality to import files from your local workstation into Hue because it may cause errors. You may not see the Local File option in the Type drop-down menu on the Importer page by default.

You can enable the functionality to import files from your local workstation by specifying the following parameter in the Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini field in Hue configurations in Cloudera Manager:

[indexer]
enable_direct_upload=true

DWX-8602: Unable to import a large CSV file from the local workstation

You may see an error message while importing a CSV file into Hue from your workstation, stating that you cannot import files of size more than 200 KB.

Upload the file to S3 or ABFS and then import them into Hue using the Importer.

CDPD-39330: Unable to use the pip command in CDP

You may not be able to use the pip command in CDP 7.1.7 or higher and may see the following error when using pip in a command: “ImportError: cannot import name chardet”.

Follow the steps listed on Unable to use pip command in CDP.

CDPD-24294: Hue uses the unsafe-inline directive in its Content Security Policy (CSP) header

Hue 4 web interface uses the unsafe-inline directive in its CSP header. As a result, the application server does not set the CSP header in its HTTP responses, and therefore does not benefit from the additional protection against potential cross-site scripting issues and other modern application vulnerabilities which a properly configured CSP may provide. This could lead to application vulnerability.

Cloudera recommends deploying additional security measures such as a firewall within the Hue server to control allowed connections, and SSO-based authentications mechanisms such as LDAP or SAML.

OPSAPS-61244: Cloudera Manager displays stale Hue configuration after upgrading to CDP 7.1.x from CDH 6.

After upgrading from CDH 6 to CDP 7.1.x, you may see stale configurations in Cloudera manager for the Hue service.

Manually restart the Hue service from Cloudera Manager.

ENGESC-9091: Setting idle session timeout for Hue does not work when the cluster is secured using Knox SSO

If Hue is configured with desktop.auth.backend.KnoxSpnegoDjangoBackend as the Authentication Backend, then the automatic idle session logout that is set by configuring the idle_session_timeout property does not take effect. You may also see 404 error while accessing Hue from the Knox UI when the idle_session_timeout property is not set to -1.

None

DOCS-10377: Hue UI is blank upon login after upgrading to CDP 7.1.7 from CDH 6

If your cluster was secured using Knox, and if you have upgraded from CDH 6 to CDP 7.1.7, then you may see a blank Hue screen. This could happen because the knox_proxyhosts parameter is newly introduced in CDP, and it is possible that this parameter is not configured in Cloudera Manager under Hue configuration.

Specify the host on which you have installed Knox in the Hue Knox Proxy Hosts configuration as follows:

1. Log in to Cloudera Manager as an Administrator.
2. Obtain the host name of the Knox Gateway by going to Clusters > Knox service > Instances.
3. Go to Clusters > Hue service > Configuration and search for the Knox Proxy Hosts field.
4. Specify the Knox Gateway hostname in the Knox Proxy Hosts field.
5. Click Save Changes and restart the Hue service.

OPSAPS-58927: Connection failed error when accessing the Search app (Solr) from Hue

If you are using Solr with Hue to generate interactive dashboards and for indexing data, and if you have deployed two Solr services on your cluster and selected the second one as a dependency for Hue, then Cloudera Manager assigns the hostname of the first Solr service and the port number of the second Solr service generating an incorrect Solr URL in the search section of the hue.ini file. As a result, you may see a “Connection failed” error when you try to access the Search app from the Hue web UI.

1. Log into Cloudera Manager as an Administrator.
2. Go to Clusters > Hue service > Configuration and add the following lines in the Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini field:

   [search]
   # URL of the Solr Server
   solr_url=http://[***HOSTNAME***]:[***PORT***]/solr/

   For example:

   solr_url=http://solr2:4567/solr/

3. Click Save Changes.
4. Restart the Hue service.

CLR-72251: Invalid S3 URI error while accessing S3 bucket

The Hue Load Balancer merges the double slashes (//) in the S3 URI into a single slash (/) so that the URI prefix "/filebrowser/view=S3A://" is changed to "/filebrowser/view=S3A:/". This results in an error when you try to access the S3 buckets from the Hue File Browser through the port 8889.

The Hue web UI displays the following error: “Unknown error occurred”.

The Hue server logs record the “ValueError: Invalid S3 URI: S3A” error.

To resolve this issue, add the following property in the Hue Load Balancer Advanced Configuration Snippet:

1. Sign in to Cloudera Manager as an administrator.
2. Go to Clusters > Hue service > Configurations > Load Balancer and search for the Load Balancer Advanced Configuration Snippet (Safety Valve) for httpd.conf field.
3. Specify MergeSlashes OFF in the Load Balancer Advanced Configuration Snippet (Safety Valve) for httpd.conf field.
4. Click Save Changes.
5. Restart the Hue Load Balancer.

   You should be able to load the S3 browser from both 8888 and 8889 ports.

   Alternatively, you can use the Hue server port 8888 instead of the load balancer port 8889 to resolve this issue.

CLR-72255: Error while rerunning Oozie workflow

You may see an error such as the following while rerunning an an already executed and finished Oozie workflow through the Hue web interface: E0504: App directory [hdfs:/cdh/user/hue/oozie/workspaces/hue-oozie-1571929263.84] does not exist.

To resolve this issue, add the following property in the Hue Load Balancer Advanced Configuration Snippet:

1. Sign in to Cloudera Manager as an administrator.
2. Go to Clusters > Hue service > Configurations > Load Balancer and search for the Load Balancer Advanced Configuration Snippet (Safety Valve) for httpd.conf field.
3. Specify MergeSlashes OFF in the Load Balancer Advanced Configuration Snippet (Safety Valve) for httpd.conf field.
4. Click Save Changes.
5. Restart the Hue Load Balancer.

CDPD-16407: Python-psycopg2 package version 2.8.4 not compatible with Hue

Ubuntu 18.04 provides python-psycopg2 package version 2.8.4 but it is not compatible with Hue because of a bug in the Django framework.

Downgrade the package at the OS level by running the following command:

sudo apt install python-psycopg2==2.7.5

or install python-psycopg2 package using pip by running the following command:

sudo pip install psycopg2==2.7.5

DOCS-6344: Hue limitation after upgrading from CDH to CDP Private Cloud Base

The hive.server2.parallel.ops.in.session configuration property changes from TRUE to FALSE after upgrading from CDH to CDP Private Cloud Base. 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.

CDPD-43956: Manually replace UUID when importing Oozie workflows containing sub-workflows

When importing Oozie workflows that contain sub-workflows, you must replace all the UUID entries with unique new entries. If you change the UUID of a sub-workflow, you must update that reference in the parent workflow to avoid circular dependencies.

INSIGHT-3707: Query history displays "Result Expired" message

You see the "Result Expired" message under the Query History column on the Queries tab for queries which were run back to back. This is a known behaviour.

None.