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Doc > Hue Administration Guide

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This guide describes how to install and configure a Hue tarball or packages. # Installation Instructions The following instructions describe how to install the Hue tarball on a multi-node cluster. You need to also install Hadoop and its satellite components (Oozie, Hive...) and update some Hadoop configuration files before running Hue. ## Install Hue consists of a web service that runs on a special node in your cluster. Choose one node where you want to run Hue. This guide refers to that node as the _Hue Server_. For optimal performance, this should be one of the nodes within your cluster, though it can be a remote node as long as there are no overly restrictive firewalls. For small clusters of less than 10 nodes, you can use your existing master node as the Hue Server. You can download the Hue tarball here: https://github.com/cloudera/hue/releases ### Hue Dependencies Hue employs some Python modules which use native code and requires certain development libraries be installed on your system. To install from the tarball, you must have the following installed: Required Dependencies The full list is here: https://github.com/cloudera/hue#development-prerequisites ### Build Configure `$PREFIX` with the path where you want to install Hue by running: PREFIX=/usr/share make install cd /usr/share/hue You can install Hue anywhere on your system, and run Hue as a non-root user. It is a good practice to create a new user for Hue and either install Hue in that user's home directory, or in a directory within `/usr/share`. ### Troubleshooting the Hue Tarball Installation .Q: I moved my Hue installation from one directory to another and now Hue no longer functions correctly. A: Due to the use of absolute paths by some Python packages, you must run a series of commands if you move your Hue installation. In the new location, run: rm app.reg rm -r build make apps .Q: Why does "make install" compile other pieces of software? A: In order to ensure that Hue is stable on a variety of distributions and architectures, it installs a Python virtual environment which includes its dependencies. This ensures that the software can depend on specific versions of various Python libraries and you don't have to be concerned about missing software components. ## Configuration Hue ships with a default configuration that will work for pseudo-distributed clusters. If you are running on a real cluster, you must make a few changes to the `hue.ini` configuration file (`/etc/hue/hue.ini` when installed from the package version) or `pseudo-distributed.ini` in `desktop/conf` when in development mode). The following sections describe the key configuration options you must make to configure Hue.
To list all available configuration options, run: $ /usr/share/hue/build/env/bin/hue config_help | less This commands outlines the various sections and options in the configuration, and provides help and information on the default values.
To view the current configuration from within Hue, open: http:///hue/dump_config
Hue loads and merges all of the files with extension `.ini` located in the `/etc/hue` directory. Files that are alphabetically later take precedence.

Web Server Configuration

These configuration variables are under the [desktop] section in the hue.ini configuration file.

Specifying the Hue HTTP Address

Hue uses CherryPy web server. You can use the following options to change the IP address and port that the web server listens on. The default setting is port 8888 on all configured IP addresses.

# Webserver listens on this address and port
http_host=0.0.0.0
http_port=8888

Specifying the Secret Key

For security, you should also specify the secret key that is used for secure hashing in the session store. Enter a long series of random characters (30 to 60 characters is recommended).

secret_key=jFE93j;2[290-eiw.KEiwN2s3['d;/.q[eIW^y#e=+Iei*@Mn<qW5o

NOTE: If you don't specify a secret key, your session cookies will not be secure. Hue will run but it will also display error messages telling you to set the secret key.

Authentication

By default, the first user who logs in to Hue can choose any username and password and becomes an administrator automatically. This user can create other user and administrator accounts. User information is stored in the Django database in the Django backend.

The authentication system is pluggable. For more information, see the Hue SDK Documentation.

List of some of the possible authentications:

Username / Password

LDAP

SAML

OpenId Connect

Configuring Hue for SSL

You can configure Hue to serve over HTTPS.

  1. Configure Hue to use your private key by adding the following options to the hue.ini configuration file:

    ssl_certificate=/path/to/certificate ssl_private_key=/path/to/key

  2. Ideally, you would have an appropriate key signed by a Certificate Authority. If you're just testing, you can create a self-signed key using the openssl command that may be installed on your system:

    Create a key

    $ openssl genrsa 1024 > host.key

    Create a self-signed certificate

    $ openssl req -new -x509 -nodes -sha1 -key host.key > host.cert

Self-signed Certificates and File Uploads To upload files using the Hue File Browser over HTTPS requires using a proper SSL Certificate. Self-signed certificates don't work.

UserAdmin Configuration

In the [useradmin] section of the configuration file, you can optionally specify the following:

default_user_group:: The name of a default group that is suggested when creating a user manually. If the LdapBackend or PamBackend are configured for doing user authentication, new users will automatically be members of the default group.

Configuration for external services

These configuration variables are under the [hadoop] section in the hue.ini configuration file.

Install Hadoop and other analytic backends

Depending on which apps you need, you need to make sure that some Hadoop services are already setup (that way Hue can talk to them).

|-------------|--------------------------------------------------------|
|  Component  | Applications                                           |
|-------------|--------------------------------------------------------|
|  Editor     | SQL (Hive, Impala, any database...), Pig, Spark...     |
|  Browsers   | YARN, Oozie, Impala, HBase, Livy                       |
|  Scheduler  | Oozie                                                  |
|  Dashboard  | Solr, SQL (Impala, Hive...)                            |
|-------------|--------------------------------------------------------|
Hadoop Configuration

You need to enable WebHdfs or run an HttpFS server. To turn on WebHDFS, add this to your hdfs-site.xml and restart your HDFS cluster. Depending on your setup, your hdfs-site.xml might be in /etc/hadoop/conf.

<property>
  <name>dfs.webhdfs.enabled</name>
  <value>true</value>
</property>

You also need to add this to core-site.xml.

<property>
  <name>hadoop.proxyuser.hue.hosts</name>
  <value>*</value>
</property>
<property>
  <name>hadoop.proxyuser.hue.groups</name>
  <value>*</value>
</property>

If you place your Hue Server outside the Hadoop cluster, you can run an HttpFS server to provide Hue access to HDFS. The HttpFS service requires only one port to be opened to the cluster.

Also add this in httpfs-site.xml which might be in /etc/hadoop-httpfs/conf.

<property>
  <name>httpfs.proxyuser.hue.hosts</name>
  <value>*</value>
</property>
<property>
  <name>httpfs.proxyuser.hue.groups</name>
  <value>*</value>
</property>

Configure Oozie

Hue submits MapReduce jobs to Oozie as the logged in user. You need to configure Oozie to accept the hue user to be a proxyuser. Specify this in your oozie-site.xml (even in a non-secure cluster), and restart Oozie:

<property>
    <name>oozie.service.ProxyUserService.proxyuser.hue.hosts</name>
    <value>*</value>
</property>
<property>
    <name>oozie.service.ProxyUserService.proxyuser.hue.groups</name>
    <value>*</value>
</property>

Hive Configuration

Hue's Hive SQL Editor application helps you use Hive to query your data. It depends on a Hive Server 2 running in the cluster. Please read this section to ensure a proper integration.

Your Hive data is stored in HDFS, normally under /user/hive/warehouse (or any path you specify as hive.metastore.warehouse.dir in your hive-site.xml). Make sure this location exists and is writable by the users whom you expect to be creating tables. /tmp (on the local file system) must be world-writable (1777), as Hive makes extensive use of it.

In `hue.ini`, modify `hive_conf_dir` to point to the directory containing `hive-site.xml`.

Configuring Your Firewall

Hue currently requires that the machines within your cluster can 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.

HDFS Cluster

Hue supports one HDFS cluster. That cluster should be defined under the [[[default]]] sub-section.

fs_defaultfs:: This is the equivalence of fs.defaultFS (aka fs.default.name) in Hadoop configuration.

webhdfs_url:: You can also set this to be the HttpFS url. The default value is the HTTP port on the NameNode.

hadoop_conf_dir:: This is the configuration directory of the HDFS, typically /etc/hadoop/conf.

Yarn (MR2) Cluster

Hue supports one or two Yarn clusters (two for HA). These clusters should be defined under the [[[default]]] and [[[ha]]] sub-sections.

resourcemanager_host:: The host running the ResourceManager.

resourcemanager_port:: The port for the ResourceManager REST service.

logical_name:: NameNode logical name.

submit_to:: To enable the section, set to True.

Impala Configuration

In the [impala] section of the configuration file, you can optionally specify the following:

server_host:: The hostname or IP that the Impala Server should bind to. By default it binds to localhost, and therefore only serves local IPC clients.

Hive Configuration

In the [beeswax] section of the configuration file, you can optionally specify the following:

beeswax_server_host:: The hostname or IP that the Hive Server should bind to. By default it binds to localhost, and therefore only serves local IPC clients.

hive_conf_dir:: The directory containing your hive-site.xml Hive configuration file.

Oozie Configuration

In the [liboozie] section of the configuration file, you should specify:

oozie_url:: The URL of the Oozie service. It is the same as the OOZIE_URL environment variable for Oozie.

Solr Configuration

In the [search] section of the configuration file, you should specify:

solr_url:: The URL of the Solr service.

HBase Configuration

In the [hbase] section of the configuration file, you should specify:

hbase_clusters:: Comma-separated list of HBase Thrift servers for clusters in the format of "(name|host:port)".

Configuration Validation

Hue can detect certain invalid configuration.

To view the configuration of a running Hue instance, navigate to http://myserver:8888/hue/dump_config, also accessible through the About application.

Starting Hue from the Tarball

After your cluster is running with the plugins enabled, you can start Hue on your Hue Server by running:

build/env/bin/supervisor

This will start several subprocesses, corresponding to the different Hue components. Your Hue installation is now running.

Administering Hue

Now that you've installed and started Hue, you can feel free to skip ahead to the <> section. Administrators may want to refer to this section for more details about managing and operating a Hue installation.

Hue Processes

Process Hierarchy

A script called supervisor manages all Hue processes. The supervisor is a watchdog process -- its only purpose is to spawn and monitor other processes. A standard Hue installation starts and monitors the following processes:

  • runcpserver - a web server based on CherryPy that provides the core web functionality of Hue

If you have installed other applications into your Hue instance, you may see other daemons running under the supervisor as well.

You can see the supervised processes running in the output of ps -f -u hue:

UID PID PPID C STIME TTY TIME CMD hue 8685 8679 0 Aug05 ? 00:01:39 /usr/share/hue/build/env/bin/python /usr/share/hue/build/env/bin/desktop runcpserver

Note that the supervisor automatically restarts these processes if they fail for any reason. If the processes fail repeatedly within a short time, the supervisor itself shuts down.

[[logging]]

Hue Logging

The Hue logs are found in /var/log/hue, or in a logs directory under your Hue installation root. Inside the log directory you can find:

  • An access.log file, which contains a log for all requests against the Hue web server.
  • A supervisor.log file, which contains log information for the supervisor process.
  • A supervisor.out file, which contains the stdout and stderr for the supervisor process.
  • A .log file for each supervised process described above, which contains the logs for that process.
  • A .out file for each supervised process described above, which contains the stdout and stderr for that process.

If users on your cluster have problems running Hue, you can often find error messages in these log files. If you are unable to start Hue from the init script, the supervisor.log log file can often contain clues.

Viewing Recent Log Messages Online

In addition to logging INFO level messages to the logs directory, the Hue web server keeps a small buffer of log messages at all levels in memory. You can view these logs by visiting http://myserver:8888/hue/logs. The DEBUG level messages shown can sometimes be helpful in troubleshooting issues.

Database

Hue requires a SQL database to store small amounts of data, including user account information as well as history of job submissions and Hive queries. By default, Hue is configured to use the embedded database SQLite for this purpose, and should require no configuration or management by the administrator. However, MySQL is the recommended database to use. This section contains instructions for configuring Hue to access MySQL and other databases.

Inspecting the Hue Database

The default SQLite database used by Hue is located in: /usr/share/hue/desktop/desktop.db. You can inspect this database from the command line using the sqlite3 program or typing `/usr/share/hue/build/env/bin/hue dbshell'. For example:

sqlite3 /usr/share/hue/desktop/desktop.db SQLite version 3.6.22 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> select username from auth_user; admin test sample sqlite>

It is strongly recommended that you avoid making any modifications to the database directly using SQLite, though this trick can be useful for management or troubleshooting.

Backing up the Hue Database

If you use the default SQLite database, then copy the desktop.db file to another node for backup. It is recommended that you back it up on a regular schedule, and also that you back it up before any upgrade to a new version of Hue.

Configuring Hue to Access Another Database

Although SQLite is the default database type, some advanced users may prefer to have Hue access an alternate database type. Note that if you elect to configure Hue to use an external database, upgrades may require more manual steps in the future.

The following instructions are for MySQL, though you can also configure Hue to work with other common databases such as PostgreSQL and Oracle.

Note that Hue has only been tested with SQLite and MySQL database backends.

Configuring Hue to Store Data in MySQL

To configure Hue to store data in MySQL:

  1. Create a new database in MySQL and grant privileges to a Hue user to manage this database.

mysql> create database hue; Query OK, 1 row affected (0.01 sec) mysql> grant all on hue.* to 'hue'@'localhost' identified by 'secretpassword'; Query OK, 0 rows affected (0.00 sec)

  1. Shut down Hue if it is running.
  2. To migrate your existing data to MySQL, use the following command to dump the existing database data to a text file. Note that using the ".json" extension is required.

/usr/share/hue/build/env/bin/hue dumpdata > .json

  1. Open the hue.ini file in a text editor. Directly below the [[database]] line, add the following options (and modify accordingly for your MySQL setup):

host=localhost port=3306 engine=mysql user=hue password=secretpassword name=hue

  1. As the Hue user, configure Hue to load the existing data and create the necessary database tables:

/usr/share/hue/build/env/bin/hue syncdb --noinput mysql -uhue -psecretpassword -e "DELETE FROM hue.django_content_type;" /usr/share/hue/build/env/bin/hue loaddata .json

Your system is now configured and you can start the Hue server as normal.

Reference Architecture

3 Hues and 1 Load Balancer Databases: MySQL InnoDB, PostgreSQL, Oracle LDAP Monitoring Impala HA HiveServer2 HA Downloads

Using Hue

After installation, you can use Hue by navigating to http://myserver:8888/.

The link:user-guide/index.html[user guide] will help users go through the various installed applications.

Supported Browsers

The two latest LTS versions of each browsers.

  • IE/Edge
  • Safari
  • Chrome
  • Firefox

Feedback

Your feedback is welcome. The best way to send feedback is to join the https://groups.google.com/a/cloudera.org/group/hue-user[mailing list], and send e-mail, to mailto:hue-user@cloudera.org[hue-user@cloudera.org].

Reporting Bugs

If you find that something doesn't work, it'll often be helpful to include logs from your server. (See the <> section. Please include the logs as a zip (or cut and paste the ones that look relevant) and send those with your bug reports. image:images/logs.png[]