This is the documentation for Cloudera Manager 5.0.x. Documentation for other versions is available at Cloudera Documentation.

The Hue Service

Hue is a set of web applications that enable you to interact with a CDH cluster. Hue applications let you browse HDFS, manage a Hive metastore, and run queries, Sqoop commands, Pig scripts, MapReduce and YARN jobs, and Oozie workflows.

Continue reading:

Configuring Hue to Work with High Availability
Managing Hue Analytics Data Collection
Using an External Database for Hue
Enabling Hue Applications

Configuring Hue to Work with High Availability

If your cluster has High Availability enabled, you must configure the Hue HDFS Web Interface Role property to use HTTPFS. See High Availability for Hue, Hive, and Impala for detailed instructions.

Managing Hue Analytics Data Collection

Hue tracks anonymised pages and application versions in order to gather information to help compare each application's usage levels. The data collected does not include any hostnames or IDs. For example, the data is of the form: /2.3.0/pig, /2.5.0/beeswax/execute. You can restrict data collection as follows:

Go to the Hue service.
Select Configuration > View and Edit.
Expand the Service-Wide category.
Uncheck the Enable Usage Data Collection checkbox.
Click Save Changes.
Restart the Hue service.

Using an External Database for Hue

By default, Cloudera Manager uses SQLite for the Hue database. If necessary, you can configure Cloudera Manager to use an external database such as MySQL or PostgreSQL as the database for Hue. The databases that Hue supports are listed at:

Dump the Hue Database

In the Cloudera Manager Admin Console, go to the Hue service status page.
Select Actions > Stop. Confirm you want to stop the service by clicking Stop.
Select Actions > Dump Database. Confirm you want to dump the database by clicking Dump Database.
Open the database dump file (by default /tmp/hue_database_dump.json) and remove all JSON objects with useradmin.userprofile in the model field. (You can verify the location of the database dump file by searching for Database Dump File in the Hue configuration settings.)

Configuring the Hue Server to Store Data in MySQL

Perform the steps in Dump the Hue Database.

Create a new database and grant privileges to a Hue user to manage this database. For example:

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)

Using the Cloudera Manager Admin Console, click the Hue service instance.
Select Configuration > View and Edit.
In the Category pane, click the instance of Database under Service-Wide.
Specify the settings for Hue Database Type, Hue Database Hostname, Hue Database Port, Hue Database Username, Hue Database Password, and Hue Database Name. For example, for a MySQL database on the local host, you might use the following values:
```
Hue Database Type = mysql
Hue Database Hostname = localhost
Hue Database Port = 3306
Hue Database Username = hue
Hue Database Password = secretpassword
Hue Database Name = hue
```
Optionally restore the Hue data to the new database:
1. Select Actions > Synchronize Database.
2. Determine the foreign key ID.
```
$ mysql -uhue -psecretpassword
mysql > SHOW CREATE TABLE auth_permission;
```
3. (InnoDB only) Drop the foreign key that you retrieved in the previous step.
```
mysql > ALTER TABLE auth_permission DROP FOREIGN KEY content_type_id_refs_id_XXXXXX;
```
4. Delete the rows in the django_content_type table.
```
mysql > DELETE FROM hue.django_content_type;
```
5. In Hue service instance page, click Actions > Load Database. Confirm you want to load the database by clicking Load Database.
6. (InnoDB only) Add back the foreign key.
```
mysql > ALTER TABLE auth_permission ADD FOREIGN KEY ('content_type_id') REFERENCES 'django_content_type' ('id');
```
Start the Hue service.

Configuring the Hue Server to Store Data in PostgreSQL

Perform the steps in Dump the Hue Database.

Install required packages.

RHEL

$ sudo yum install postgresql-devel gcc python-devel

SLES

$ sudo zypper install postgresql-devel gcc python-devel

Ubuntu or Debian

$ sudo apt-get install postgresql-devel gcc python-devel

Install the Python module that provides the connector to PostgreSQL:

Parcel install

$ sudo /opt/cloudera/parcels/CDH/lib/hue/build/env/bin/pip install setuptools
$ sudo /opt/cloudera/parcels/CDH/lib/hue/build/env/bin/pip install psycopg2

Package install

sudo -u hue /usr/share/hue/build/env/bin/pip install setuptools
sudo -u hue /usr/share/hue/build/env/bin/pip install psycopg2

Install the PostgreSQL server.

RHEL

$ sudo yum install postgresql-server

SLES

$ sudo zypper install postgresql-server

Ubuntu or Debian

$ sudo apt-get install postgresql

Initialize the data directories.
```
$ service postgresql initdb
```
Configure client authentication.
1. Edit /var/lib/pgsql/data/pg_hba.conf.
2. Set the authentication methods for local to trust and for host to password and add the following line at the end.
```
host hue hue 0.0.0.0/0 md5
```

Start the PostgreSQL server.

$ su - postgres
# /usr/bin/postgres -D /var/lib/pgsql/data > logfile 2>&1 &

Configure PostgreSQL to listen on all network interfaces.
1. Edit /var/lib/pgsql/data/postgresql.conf and set list_addresses.
```
listen_addresses = ‘0.0.0.0’     # Listen on all addresses
```

Create the hue database and grant privileges to a hue user to manage the database.

# psql -U postgres
postgres=# create database hue;
postgres=# \c hue;
You are now connected to database 'hue'.
postgres=# create user hue with password 'secretpassword';
postgres=# grant all privileges on database hue to hue;
postgres=# \q

Restart the PostgreSQL server.
```
$ sudo service postgresql restart
```

Verify connectivity.

psql –h localhost –U hue –d hue
Password for user hue: secretpassword

Configure the PostgreSQL server to start at boot.

RHEL

$ sudo /sbin/chkconfig postgresql on
$ sudo /sbin/chkconfig --list postgresql
postgresql          0:off   1:off   2:on    3:on    4:on    5:on    6:off

SLES

$ sudo chkconfig --add postgresql

Ubuntu or Debian

$ sudo chkconfig postgresql on

Using the Cloudera Manager Admin Console, click the Hue service instance.
Select Configuration > View and Edit.
In the Category pane, click Advanced under Service-Wide.

Specify the settings for Hue Server Configuration Advanced Configuration Snippet:

[desktop]
[[database]]
host=localhost
port=5432
engine=postgresql_psycopg2
user=hue
password=secretpassword
name=hue

Click Save Changes.

Optionally restore the Hue data to the new database:

Select Actions > Synchronize Database.

Determine the foreign key ID.

bash# su – postgres
$ psql –h localhost –U hue –d hue
postgres=# \d auth_permission;

Drop the foreign key that you retrieved in the previous step.

postgres=# ALTER TABLE auth_permission DROP CONSTRAINT content_type_id_refs_id_XXXXXX;

Delete the rows in the django_content_type table.

postgres=# TRUNCATE django_content_type CASCADE;

In Hue service instance page, Actions > Load Database. Confirm you want to load the database by clicking Load Database.

Add back the foreign key you dropped.

bash# su – postgres
$ psql –h localhost –U hue –d hue
postgres=# ALTER TABLE auth_permission ADD CONSTRAINT content_type_id_refs_id_XXXXXX FOREIGN KEY (content_type_id) REFERENCES django_content_type(id) DEFERRABLE INITIALLY DEFERRED;

Start the Hue service.

Enabling Hue Applications

Most Hue applications are configured by default, based on the services you have installed. Cloudera Manager selects the service instance that Hue depends on. If you have more than one service, you may want to verify or change the service dependency for Hue. Also, if you add a service such as Sqoop2 or Oozie after you have set up Hue, you will need to set the dependency because it won't be done automatically. To add a dependency:

Go to the Hue service.
Select Configuration > View and Edit.
Select the Service-Wide category.
Change the setting for the service dependency from None to the appropriate service instance.
Click Save Changes.
Restart the Hue service.

Enabling the Sqoop2 Application

If you upgrade to Cloudera Manager 4.7 from an earlier version of Cloudera Manager 4, you will need to set the Hue dependency to enable the Sqoop2 application.

Enabling the HBase Browser Application

The HBase Browser application, new as of CDH 4.4, depends on the HBase Thrift server for its functionality. The Thrift server role is not added by default when you install HBase, so in order to use the HBase Browser:

Add a Thrift Server role:
1. Select the HBase service, then select the Instances tab.
2. Click the Add button.
3. Select the host(s) where you want to add the Thrift Server role (you only need one for Hue) and click Continue. The Thrift server role should appear in the instances list for the HBase server.
4. Select the Thrift Server role instance, and from the Actions for Selected menu, Start the role.
Configure Hue to point to the Thrift Server:
1. Select the Hue service.
2. Select Configuration > View and Edit.
3. Go to the Service-Wide category.
4. For the HBase Service property, make sure it is set to the HBase service for which you enabled the Thrift Server role (if you have more than one HBase service instance).
5. In the HBase Thrift Server property, click in the edit field and select the Thrift Server role that Hue should use.
6. Save Changes.

Enabling the Impala Application

To use the Cloudera Impala Query UI , you must add the host name of the Impala Daemon in the Hue Server advanced configuration snippet. See Deploying Impala with Hue for detailed instructions.

Enabling the Solr Search Application

To use the Solr Search application with Hue, you must update the URL for the Solr Server in the Hue Server advanced configuration snippet. In addition, if you are using parcels with CDH 4.3, you must register the "hue-search" application manually or access will fail. You do not need to do this if you are using CDH 4.4 or later. See Deploying Solr with Hue for detailed instructions.

Page generated September 3, 2015.