Table of Contents
2. Hue Installation Instructions
2.2. Install Hadoop from CDH
2.4. Further Hadoop Configuration and Caveats
3.1. Web Server Configuration
3.2. Hue Configuration for Hadoop
3.3. Beeswax Configuration
3.4. JobDesigner and Oozie Configuration
3.5. UserAdmin Configuration
3.6. Configuration Validation
4. Starting Hue from the Tarball
1. Introduction
Hue is a graphical user interface to operate and develop applications for Apache Hadoop. Hue applications are collected into a desktop-style environment and delivered as a Web application, requiring no additional installation for individual users.
This guide describes how to install and configure a Hue tarball. For information about installing Hue packages, see Installing Hue.
There is also a companion SDK guide that describes how to develop new Hue applications: Hue SDK Documentation
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Hue requires the Hadoop contained in Cloudera’s Distribution including Apache Hadoop (CDH4) |
Conventions Used in this Guide:
- Commands that must be run with
root
permission have a #
command prompt. - Commands that do not require
root
permission have a $
command prompt.
2. Hue Installation Instructions
The following instructions describe how to install the Hue tarball on a multi-node cluster. You need to also install CDH and update some Hadoop configuration files before running Hue.
2.1. Install Hue
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: gethue.tumblr.com/tagged/release
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:
Table 1. Required Dependencies
Redhat | Ubuntu |
gcc | gcc |
g++ | g++ |
libxml2-devel | libxml2-dev |
libxslt-devel | libxslt-dev |
cyrus-sasl-devel | libsasl2-dev |
cyrus-sasl-gssapi | libsasl2-modules-gssapi-mit |
mysql-devel | libmysqlclient-dev |
python-devel | python-dev |
python-setuptools | python-setuptools |
python-simplejson | python-simplejson |
sqlite-devel | libsqlite3-dev |
ant | ant |
libsasl2-dev | cyrus-sasl-devel |
libsasl2-modules-gssapi-mit | cyrus-sasl-gssapi |
libkrb5-dev | krb5-devel |
libtidy-0.99-0 | libtidy (For unit tests only) |
mvn | mvn (From maven2 package or tarball) |
openldap-dev / libldap2-dev | openldap-devel |
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. The Shell application needs root privileges to launch various sub-processes as the logged in users. $USER
should be the group of the user running Hue (same as its username).
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.
2.2. Install Hadoop from CDH
To use Hue, you must install and run Hadoop from CDH4 or later. If you are not running this version of CDH or later, upgrade your cluster before proceeding.
Table 2. Dependency on CDH Components
Component | Required | Applications | Notes |
HDFS | Yes | Core, Filebrowser | HDFS access through WebHdfs or HttpFS |
MR1 | No | JobBrowser, JobDesigner, Beeswax | Job information access through hue-plugins |
Yarn | No | JobDesigner, Beeswax | Transitive dependency via Hive or Oozie |
Oozie | No | JobDesigner, Oozie | Oozie access through REST API |
Hive | No | Beeswax | Beeswax uses the Hive client libraries |
HBase | No | HBase Browser | Requires Thrift 1 service |
Pig | No | Pig Editor | Requires Oozie |
Sqoop2 | No | Sqoop Editor | Requires Sqoop2 server |
2.3. Hadoop Configuration
Configure WebHdfs
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.html
.
<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 MapReduce 0.20 (MR1)
Hue communicates with the JobTracker via the Hue plugins, which is a jar file that you place in your MapReduce lib
directory.
If you JobTracker and Hue are located on the same host, copy it over. If you are using CDH3, your MapReduce library directory might be in/usr/lib/hadoop/lib
.
$ cd /usr/share/hue $ cp desktop/libs/hadoop/java-lib/hue-plugins-*.jar /usr/lib/hadoop-0.20-mapreduce/lib
If you JobTracker runs on a different host, you need to scp
the Hue plugins jar to the JobTracker host.
Then add this to your mapred-site.xml
and restart your JobTracker. Depending on your setup, your mapred-site.xml
might be in /etc/hadoop/conf
.
<property> <name>jobtracker.thrift.address</name> <value>0.0.0.0:9290</value> </property> <property> <name>mapred.jobtracker.plugins</name> <value>org.apache.hadoop.thriftfs.ThriftJobTrackerPlugin</value> <description>Comma-separated list of jobtracker plug-ins to be activated.</description> </property>
You can confirm that the plugins are running correctly by tailing the daemon logs:
$ tail --lines=500 /var/log/hadoop-0.20/hadoop*jobtracker*.log | grep ThriftPlugin 2009-09-28 16:30:44,337 INFO org.apache.hadoop.thriftfs.ThriftPluginServer: Starting Thrift server 2009-09-28 16:30:44,419 INFO org.apache.hadoop.thriftfs.ThriftPluginServer: Thrift server listening on 0.0.0.0:9290
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>
2.4. Further Hadoop Configuration and Caveats
HADOOP_CLASSPATH
Caveat
If you are setting $HADOOP_CLASSPATH
in your hadoop-env.sh
, be sure to set it in such a way that user-specified options are preserved. For example:
Correct:
# HADOOP_CLASSPATH=<your_additions>:$HADOOP_CLASSPATH
Incorrect:
# HADOOP_CLASSPATH=<your_additions>
This enables certain components of Hue to add to Hadoop’s classpath using the environment variable.
hadoop.tmp.dir
If your users are likely to be submitting jobs both using Hue and from the same machine via the command line interface, they will be doing so as the hue
user if they’re using Hue and via their own user account on the command line. This leads to some contention on the directory specified by hadoop.tmp.dir
, which defaults to /tmp/hadoop-${user.name}
. Specifically, hadoop.tmp.dir
is used to unpack jars in bin/hadoop jar
. One work around to this is to set hadoop.tmp.dir
to /tmp/hadoop-${user.name}-${hue.suffix}
in the core-site.xml file:
<property> <name>hadoop.tmp.dir</name> <value>/tmp/hadoop-${user.name}${hue.suffix}</value> </property>
Unfortunately, when the variable is unset, you’ll end up with directories named /tmp/hadoop-user_name-${hue.suffix}
in /tmp
. Despite that, Hue will still work.
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The Beeswax server writes into a local directory on the Hue machine that is specified by |
Configuring Your Firewall for Hue
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.
2.5. Hive Configuration
Hue’s Beeswax 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.
Familiarize yourself with the configuration options in hive-site.xml
. See Hive Installation and Configuration. Having a hive-site.xml
is optional but often useful, particularly on setting up a metastore. You may store the hive-site.xml
in /etc/hue
, or instruct Beeswax to locate it using thehive_conf_dir
configuration variable. See hue.ini
.
Existing Hive Installation
In hue.ini
, modify hive_conf_dir
to point to the directory containing hive-site.xml
.
3. Configuring Hue
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 CDH 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.
Listing all Configuration Options | |
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. |
Viewing Current Configuration Options | |
To view the current configuration from within Hue, open: |
Using Multiple Files to Store Your Configuration | |
Hue loads and merges all of the files with extension |
3.1. 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
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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.
Configuring Hue for SSL
You can configure Hue to serve over HTTPS. To do so, you must install "pyOpenSSL" within Hue’s context and configure your keys.
To install pyOpenSSL
, from the root of your Hue installation path, do the following steps:
- Run this command: $ ./build/env/bin/easy_install pyOpenSSL
- 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 - 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. |
3.2. Hue Configuration for Hadoop
These configuration variables are under the [hadoop]
section in the hue.ini
configuration file.
HDFS Cluster
Hue only support one HDFS cluster currently. 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_hdfs_home
This is the home of your Hadoop HDFS installation. It is the root of the Hadoop untarred directory, or usually
/usr/lib/hadoop
.
hadoop_bin
Use this as the HDFS Hadoop launcher script, which is usually
/usr/bin/hadoop
.
hadoop_conf_dir
This is the configuration directory of the HDFS, typically
/etc/hadoop/conf
.
MapReduce (MR1) Cluster
Hue only support one MapReduce cluster currently. That cluster should be defined under the [[[default]]]
sub-section. Note that JobBrowser only works with MR1.
jobtracker_host
The host running the JobTracker. In a secured environment, this needs to be the FQDN of the JobTracker host, and match the "host" portion of the ‘mapred’ Kerberos principal full name.
jobtracker_port
The port for the JobTracker IPC service.
submit_to
If your Oozie is configured with to talk to a 0.20 MapReduce service, then set this to
true
. Hue will be submitting jobs to this MapReduce cluster.
hadoop_mapred_home
This is the home of your Hadoop MapReduce installation. It is the root of the Hadoop MR1 untarred directory, or the root of the Hadoop 0.20 untarred directory, or
/usr/lib/hadoop-0.20-mapreduce
for CDH packages. If
submit_to
is true for this cluster, this config value becomes the
$HADOOP_MAPRED_HOME
for BeeswaxServer and child shell processes.
hadoop_bin
Use this as the MR1 Hadoop launcher script, which is usually
/usr/bin/hadoop
.
hadoop_conf_dir
This is the configuration directory of the MR1 service, typically
/etc/hadoop/conf
.
Yarn (MR2) Cluster
Hue only support one Yarn cluster currently. That cluster should be defined under the [[[default]]]
sub-section.
resourcemanager_host
The host running the ResourceManager.
resourcemanager_port
The port for the ResourceManager IPC service.
submit_to
If your Oozie is configured with to talk to a Yarn cluster, then set this to
true
. Hue will be submitting jobs to this Yarn cluster. But note that JobBrowser will not be able to show MR2 jobs.
hadoop_mapred_home
This is the home of your Hadoop MapReduce installation. It is the root of the Hadoop 0.23 untarred directory, or
/usr/lib/hadoop-mapreduce
for CDH packages. If
submit_to
is true for this cluster, this config value becomes the
$HADOOP_MAPRED_HOME
for BeeswaxServer and child shell processes.
hadoop_bin
Use this as the Yarn/MR2 Hadoop launcher script, which is usually
/usr/bin/hadoop
.
hadoop_conf_dir
This is the configuration directory of the Yarn/MR2 service, typically
/etc/hadoop/conf
.
3.3. Beeswax Configuration
In the [beeswax]
section of the configuration file, you can optionally
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_home_dir
The base directory of your Hive installation.
hive_conf_dir
The directory containing your
hive-site.xml
Hive configuration file.
3.4. JobDesigner and 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.
3.5. UserAdmin Configuration
In the [useradmin]
section of the configuration file, you can optionally
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.
3.6. Configuration Validation
Hue can detect certain invalid configuration. It will show a red alert icon on the top navigation bar.
To view the configuration of a running Hue instance, navigate to http://myserver:8888/dump_config
, also accessible through the About application.
4. 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.
5. Administering Hue
Now that you’ve installed and started Hue, you can feel free to skip ahead to the Using Hue section. Administrators may want to refer to this section for more details about managing and operating a Hue installation.
5.1. Hue Processes
Process User
Filebrowser requires Hue to be running as the hue
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.
5.2. 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/logs
. The DEBUG
level messages shown can sometimes be helpful in troubleshooting issues.
5.3. The Hue 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.
Tested Database Backends | |
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:
- 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)
- Shut down Hue if it is running.
- 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 > <some-temporary-file>.json
- 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 - 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 <temporary-file-containing-dumped-data>.json
Your system is now configured and you can start the Hue server as normal.
6. Using Hue
After installation, you can use Hue by navigating to http://myserver:8888/
. The following login screen appears:
The Help application guides users through the various installed applications.
6.1. Supported Browsers
- Windows: Chrome, Firefox 3.6+, Internet Explorer 9+, Safari 5+
- Linux : Chrome, Firefox 3.6+
- Mac: Chrome, Firefox 3.6+, Safari 5+
6.2. Feedback
Your feedback is welcome. The best way to send feedback is to join the mailing list, and send e-mail, to hue-user@cloudera.org.
6.3. Reporting Bugs
If you find that something doesn’t work, it’ll often be helpful to include logs from your server. (See the Hue Logging section. Please include the logs as a zip (or cut and paste the ones that look relevant) and send those with your bug reports.
启动 /usr/share/hue/build/env/bin/supervisor