Administering Hue

This page explains how to manage and operate a Hue installation:

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Hue Superusers and Users

The Hue User Admin application provides two levels of privileges: superusers and users.

  • Superusers — The first user who logs into Hue after its installation becomes the first superuser. Superusers can perform administrative functions such as:
    • Add and delete users
    • Add and delete groups
    • Assign permissions to groups
    • Change a user to a superuser
    • Import users and groups from an LDAP server

  • Users — Can change their name, email address, and password. They can login to Hue and run Hue applications according to their group permissions.

Hue UI Customization

The Hue Web UI has the following customization options in hue.ini under [desktop] > [[custom]].

Banner

You can add a custom banner to the Hue Web UI by applying HTML directly to the property, banner_top_html. For example: 
banner_top_html=<H4>My company's custom Hue Web UI banner</H4>
To configure a banner in Cloudera Manager:
  1. Go to the Hue service.
  2. Click the Configuration tab.
  3. Select Scope > Hue Server and Category > Advanced.
  4. Locate Top Banner Custom HTML and input your desired HTML in the text field.
  5. Click Save Changes to commit the changes.
  6. Select Actions > Restart and, when done, click Close.
  7. Click Web UI to view your changes.

Splash Screen

You can customize a splash screen on the login page by applying HTML directly to the property, login_splash_html. For example: 
login_splash_html=WARNING: You are required to have authorization before you proceed.
To configure a splash screen in Cloudera Manager:
  1. Go to the Hue service.
  2. Click the Configuration tab.
  3. Select Scope > HUE-1 (Service-Wide) and Category > Advanced.
  4. Locate Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini and add your HTML in the text field as follows: 
    [dekstop]
[[custom]]
login_splash_html=WARNING: You are required to have authorization before you proceed.
  5. Click Save Changes to commit the changes.
  6. Select Actions > Restart and, when done, click Close.
  7. Click Web UI to view your changes.

Cache Timeout

You enable Hue UI caching by setting a timeout in milliseconds. The default is 86400000 milliseconds or one day. Set the timeout to 0 to disable caching.

As with the splash screen, set the cache timeout in Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini. 
[dekstop]
[[custom]]
cacheable_ttl=86400000

Starting and Stopping the Hue Server

The hue-server package includes service scripts to start and stop the Hue Server.

To start the Hue Server:

$ sudo service hue start

To restart the Hue Server:

$ sudo service hue restart

To stop the Hue Server:

$ sudo service hue stop

Configuring a Firewall for Hue

Hue currently requires that the machines in your cluster connect to each other freely over TCP. The machines outside your cluster must be able to open TCP port 8888 on the Hue Server (or the configured Hue web HTTP port) to interact with the system.

Anonymous Usage Data Collection

Hue tracks anonymized pages and application versions to gather information about application usage levels. The data collected does not include any hostnames or IDs.

For Hue 2.5.0 and higher, you can restrict this data collection by setting the collect_usage property to false in the [desktop] section in the Hue configuration file, hue.ini.

[desktop]
...
# Help improve Hue with anonymous usage analytics. 
# Use Google Analytics to see how many times an application or specific section of an application is used, nothing more.  
## collect_usage=false

If you are using an earlier version of Hue, disable this data collection by going to Step 3 of Hue's Quick Start Wizard. Under Anonymous usage analytics, uncheck the box for Check to enable usage analytics.

Managing Hue Processes

The supervisor script manages all Hue processes. The supervisor is a watchdog process; its only purpose is to spawn and monitor other processes. To see active supervised processes, run ps -f -u hue.

A standard Hue installation starts and monitors the runcpserver process, which provides the core web functionality for Hue. If you installed other applications into your Hue instance, you may see other daemons running under the supervisor as well.

Supervisor automatically restarts these processes if they fail for any reason. If they fail repeatedly in a short period of time, the supervisor itself shuts down.

Viewing Hue Logs

Hue logs are stored in /var/log/hue. In the Hue UI, select About Hue > Server Logs. You can also view these logs at http://myserver:port/logs.

Hue generates .log and .out files for each supervised process. The .log files write log information with log4j. The .out files write standard output (stdout) and standard error (stderr) streams.

The following Hue logs are available.

Log Name

 Description
access.log Filtered list of all successful attempts to access the Hue Web UI
audit.log Audit log visible in Cloudera Navigator
collectstatic.log Static files that support the Hue Web UI (images, JavaScript files, .css, and so on)
error.log Filtered list of all nontrivial errors
kt_renewer.log Kerberos ticket renews
metrics_hue_server.log Usage data for monitoring in Cloudera Manager
migrate.log Database and table migrations
runcpserver.log Hue (CherryPy) web server info
syncdb.log Database and table creations

The Hue Server logs INFO level messages and keeps a small buffer of log messages at all levels in memory. The DEBUG level messages can sometimes be helpful in troubleshooting issues.