Known Issues in Hue

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

CDPD-40354: Uploading large files to WebHDFS from Hue secured using Knox fails

When you upload files larger than 300 MB to WebHDFS using Hue File Browser from a Hue instance that is secured using Knox, the upload fails and you see the following error on the Hue web interface: 502 bad gateway nginx error. This error occus only when you access the Hue instance from the Knox Gateway. Also, you may not find any exceptions in Hue or Knox service logs.

This issue is caused because the value of the addExpect100Continue is set to true. Therefore streaming large files causes out of memory error in Knox.

To resolve the issue, you must set the value of the addExpect100Continue to false.

1. SSH in to the Knox host as an Administrator.
2. Back up the following files:
   • /opt/cloudera/parcels/CDH-[***VERSION***]/lib/knox/data/services/hue/1.0.0/service.xml
   • /var/lib/knox/gateway/data/services/hue/1.0.0/service.xml
3. Open the /opt/cloudera/parcels/CDH-[***VERSION***]/lib/knox/data/services/hue/1.0.0/service.xml file for editing, search for the addExpect100Continue property, and set the value of this property to false as follows:

   <param>
      <name>addExpect100Continue</name>
      <value>false</value>
   </param>

4. Save the file and exit.
5. Open the /var/lib/knox/gateway/data/services/hue/1.0.0/service.xml file for editing, search for the addExpect100Continue property, and set the value of this property to false as follows:

   <param>
      <name>addExpect100Continue</name>
      <value>false</value>
   </param>

6. Save the file and exit.
7. Delete the deployment directory as follows:

   rm -rf /var/lib/knox/gateway/data/deployments/

8. Restart the Knox 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-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-46312: cx_Oracle 6.4.1 is missing from the CDP stack on 7.1.8 release

cx_Oracle and Oracle Instant Client parcels are not bundled in the CDP 7.1.8 distribution.

You must download the Oracle Instant Client library 19.16 (both basic and SDK clients) from the Oracle website. You can download the cx_Oracle Python extension module from https://pypi.org/project/cx-Oracle/. The documentation has also been updated to provide you these instructions. See Using Oracle database with Hue.

OPSAPS-64655: Performance issues in loading and using Hue

You may experience delay in loading the Hue application, running queries, or see a blank page when you try to open Hue. This could happen because of slower responses from the Hue server due to a limited number of Gunicorn worker processes.

To improve performance, increase the number of Gunicorn worker processes. Go to Cloudera Manager > Clusters > Hue > Configuration and add the following lines in the Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini field:

[desktop]
gunicorn_number_of_workers=32
cherrypy_server_threads=2

Click Save Changes and restart the Hue service.

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-17465: LDAPTest fails with whoami_s

LDAPTest can potentially fail when the extended operation “whoami_s” is not available.

None.

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 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.

This issue will be fixed in Hue 5. Until then, 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.