Using an External Database for Hue Using the Command Line

The Hue server requires a SQL database to store small amounts of data such as user account information, job submissions, and Hive queries. SQLite is the default embedded database. Hue also supports several types of external databases. This page explains how to configure Hue with a selection of external Supported Databases.

Continue reading:

Embedded Database
External Database

Embedded Database

By default, Hue is configured to use the embedded database, SQLite, and should require no configuration or management by the administrator.

Inspecting the Embedded Hue Database

The default SQLite database is located in /var/lib/hue/desktop.db. You can inspect this database from the command line with the sqlite3 program. For example:

# sqlite3 /var/lib/hue/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>

Backing up the Embedded Hue Database

If you use the default embedded SQLite database, copy the desktop.db file to another node for backup. Cloudera recommends that you backup regularly, and also that you backup before upgrading to a new version of Hue.

External Database

Cloudera strongly recommends an external database for clusters with multiple Hue users, especially clusters in a production environment. The default embedded database, SQLite, cannot support large data migrations. See Supported Databases.

High-level steps to configure Hue with any of the supported external databases are:

Stop Hue service.
Backup default SQLite database.
Install database software and dependencies.
Create and configure database and load data.
Start Hue service.

If you do not need to migrate a SQLite database, you can skip the steps on dumping the database and editing the JSON objects.

Continue Reading:

Prerequisites

Before configuring Hue to use an external database:

Install all support libraries required by your operating system. See Development Preferences in the Hue documentation for the full list.
Ensure the Hue server is running on Python 2.6 or higher.

Configuring the Hue Server to Store Data in MariaDB

Shut down the Hue server if it is running.

Open <some-temporary-file>.json and remove all JSON objects with useradmin.userprofile in the model field. Here are some examples of JSON objects that should be deleted.

{
    "pk": 1,
     "model":  "useradmin.userprofile",
     "fields": {
       "creation_method":  "HUE",
       "user": 1,
       "home_directory":  "/user/alice"
    }
  },
  {
     "pk": 2,
     "model":  "useradmin.userprofile",
     "fields": {
       "creation_method":  "HUE",
       "user": 1100714,
       "home_directory":  "/user/bob"
    }
  },
.....

Start the Hue server.

Install the MariaDB client developer package.

OS	Command
RHEL	$ sudo yum install mariadb-devel
SLES	$ sudo zypper install mariadb-devel
Ubuntu or Debian	$ sudo apt-get install libmariadbclient-dev

Install the MariaDB connector.

OS	Command
RHEL	$ sudo yum install mariadb-connector-java
SLES	$ sudo zypper install mariadb-connector-java
Ubuntu or Debian	$ sudo apt-get install libmariadb-java

Install and start MariaDB.

OS	Command
RHEL	$ sudo yum install mariadb-server
SLES	$ sudo zypper install mariadb-server $ sudo zypper install libmariadblclient18
Ubuntu or Debian	$ sudo apt-get install mariadb-server

Change the /etc/my.cnf file as follows:

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
bind-address=<ip-address>
default-storage-engine=InnoDB
sql_mode=STRICT_ALL_TABLES

Start the MariaDB daemon.
```
$ sudo service mariadb start
```

Configure MariaDB to use a strong password. In the following procedure, your current root password is blank. Press the Enter key when you're prompted for the root password.

$ sudo /usr/bin/mysql_secure_installation
[...]
Enter current password for root (enter for none):
OK, successfully used password, moving on...
[...]
Set root password? [Y/n] y
New password:
Re-enter new password:
Remove anonymous users? [Y/n] Y
[...]
Disallow root login remotely? [Y/n] N
[...]
Remove test database and access to it [Y/n] Y
[...]
Reload privilege tables now? [Y/n] Y
All done!

Configure MariaDB to start at boot.

OS	Command
RHEL	$ sudo /sbin/chkconfig mariadb on $ sudo /sbin/chkconfig --list mariadb mysqld 0:off 1:off 2:on 3:on 4:on 5:on 6:off
SLES	$ sudo chkconfig --add mariadb
Ubuntu or Debian	$ sudo chkconfig mariadb on

Create the Hue database and grant privileges to a hue user to manage the 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)

Open the Hue configuration file in a text editor.
Edit the Hue configuration file hue.ini. Directly below the [[database]] section under the [desktop] line, add the following options (and modify accordingly for your setup):
```
host=localhost
port=3306
engine=mysql
user=hue
password=<secretpassword>
name=hue
```
As the hue user, load the existing data and create the necessary database tables using syncdb and migrate commands. When running these commands, Hue will try to access a logs directory, located at /opt/cloudera/parcels/CDH/lib/hue/logs, which might be missing. If that is the case, first create the logs directory and give the hue user and group ownership of the directory.
Note: HUE_HOME is a reference to the location of your Hue installation. For package installs, this is usually /usr/lib/hue; for parcel installs, this is usually, /opt/cloudera/parcels/<parcel version>/lib/hue/.
```
$ sudo mkdir /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo chown hue:hue /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo -u hue <HUE_HOME>/build/env/bin/hue syncdb --noinput
$ sudo -u hue <HUE_HOME>/build/env/bin/hue migrate
$ mysql -u hue -p <secretpassword>
mysql > SHOW CREATE TABLE auth_permission;
```

(InnoDB only) Drop the foreign key.

mysql > ALTER TABLE auth_permission DROP FOREIGN KEY content_type_id_refs_id_XXXXXX;

Delete the rows in the django_content_type table.
```
mysql > DELETE FROM hue.django_content_type;
```

Load the data.

$ <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json

(InnoDB only) Add the foreign key.

$ mysql -u hue -p <secretpassword>
mysql > ALTER TABLE auth_permission ADD FOREIGN KEY (`content_type_id`) REFERENCES `django_content_type` (`id`);

Configuring the Hue Server to Store Data in MySQL

Stop the Hue server, if running.
```
sudo service hue stop
```

Backup the existing database:

Dump the existing database data to a .json file.
```
$ sudo -u hue <HUE_HOME>/build/env/bin/hue dumpdata > <some-temporary-file>.json
```
Note: HUE_HOME refers to the location of your Hue installation. For package installs, this is usually /usr/lib/hue; for parcel installs, this is usually, /opt/cloudera/parcels/<parcel version>/lib/hue/.

Delete all JSON objects with useradmin.userprofile in the model field from <some-temporary-file>.json. For example.

{
    "pk": 1,
     "model":  "useradmin.userprofile",
     "fields": {
       "creation_method":  "HUE",
       "user": 1,
       "home_directory":  "/user/alice"
    }
  },
  {
     "pk": 2,
     "model":  "useradmin.userprofile",
     "fields": {
       "creation_method":  "HUE",
       "user": 1100714,
       "home_directory":  "/user/bob"
    }
  },
.....

Install and configure MySQL as an external database for Hue:

Install the MySQL client developer package.

OS	Command
RHEL	$ sudo yum install mysql-devel
SLES	$ sudo zypper install mysql-devel
Ubuntu or Debian	$ sudo apt-get install libmysqlclient-dev

Install the MySQL connector.

OS	Command
RHEL	$ sudo yum install mysql-connector-java
SLES	$ sudo zypper install mysql-connector-java
Ubuntu or Debian	$ sudo apt-get install libmysql-java

Install the MySQL server.

OS	Command
RHEL	$ sudo yum install mysql-server
SLES	$ sudo zypper install mysql $ sudo zypper install libmysqlclient_r15
Ubuntu or Debian	$ sudo apt-get install mysql-server

Configure /etc/my.cnf as follows:

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
bind-address=<ip-address>
default-storage-engine=InnoDB
sql_mode=STRICT_ALL_TABLES

Start the MySQL daemon.
OS Command
RHEL

$ sudo service mysqld start
SLES and Ubuntu or Debian

$ sudo service mysql start

OS	Command
RHEL	$ sudo service mysqld start
SLES and Ubuntu or Debian	$ sudo service mysql start

Configure MySQL with a strong password. Press the Enter key when you're prompted for the root password (as your current root password is blank).

$ sudo /usr/bin/mysql_secure_installation
[...]
Enter current password for root (enter for none):
OK, successfully used password, moving on...
[...]
Set root password? [Y/n] y
New password:
Re-enter new password:
Remove anonymous users? [Y/n] Y
[...]
Disallow root login remotely? [Y/n] N
[...]
Remove test database and access to it [Y/n] Y
[...]
Reload privilege tables now? [Y/n] Y
All done!

Configure MySQL to start at boot.

OS	Command
RHEL	$ sudo /sbin/chkconfig mysqld on $ sudo /sbin/chkconfig --list mysqld mysqld 0:off 1:off 2:on 3:on 4:on 5:on 6:off
SLES	$ sudo chkconfig --add mysql
Ubuntu or Debian	$ sudo chkconfig mysql on

Create the database, hue:
```
mysql> create database hue;
```

Grant privileges:

mysql> grant all on hue.* to 'hue'@'localhost' identified by '<secretpassword>';

Configure /etc/hue/conf/hue.ini to use MySQL. Modify these options as appropriate and paste below [[database]] and [desktop]:
```
host=localhost
port=3306
engine=mysql
user=hue
password=<secretpassword>
name=hue
```

Load any backed up data:

Ensure a logs directory exists and is writable at /opt/cloudera/parcels/CDH/lib/hue/logs.
Ensure the logs directory has hue user and group ownership.

Synchronize and migrate the database.

$ sudo mkdir /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo chown hue:hue /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo -u hue <HUE_HOME>/build/env/bin/hue syncdb --noinput
$ sudo -u hue <HUE_HOME>/build/env/bin/hue migrate
$ mysql -u hue -p <secretpassword>
mysql > SHOW CREATE TABLE auth_permission;

(InnoDB only) Drop the foreign key:

mysql > ALTER TABLE auth_permission DROP FOREIGN KEY content_type_id_refs_id_XXXXXX;

Delete the rows in the django_content_type table:
```
mysql > DELETE FROM hue.django_content_type;
```

Load the data:

$ <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json

(InnoDB only) Add the foreign key:

$ mysql -u hue -p <secretpassword>
mysql > ALTER TABLE auth_permission ADD FOREIGN KEY (`content_type_id`)
REFERENCES `django_content_type` (`id`);

Start the Hue server.
```
sudo service hue start
```

Configuring the Hue Server to Store Data in PostgreSQL

Stop the Hue server, if running.
```
sudo service hue stop
```

Backup the existing database:

Dump the existing database data to a .json file.
```
$ sudo -u hue <HUE_HOME>/build/env/bin/hue dumpdata > <some-temporary-file>.json
```
Note: HUE_HOME refers to the location of your Hue installation. For package installs, this is usually /usr/lib/hue; for parcel installs, this is usually, /opt/cloudera/parcels/<parcel version>/lib/hue/.

Delete all JSON objects with useradmin.userprofile in the model field from <some-temporary-file>.json. For example.

{
    "pk": 1,
     "model":  "useradmin.userprofile",
     "fields": {
       "creation_method":  "HUE",
       "user": 1,
       "home_directory":  "/user/alice"
    }
  },
  {
     "pk": 2,
     "model":  "useradmin.userprofile",
     "fields": {
       "creation_method":  "HUE",
       "user": 1100714,
       "home_directory":  "/user/bob"
    }
  },
.....

Install the PostgreSQL client dev packages.

OS	Commandcd /
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 modules that provide the PostgreSQL connector.

sudo -u hue <HUE_HOME>/build/env/bin/pip install setuptools
sudo -u hue <HUE_HOME>/build/env/bin/pip install psycopg2

Install the PostgreSQL server.

OS	Command
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 /var/lib/pgsql/data/pg_hba.conf for client authentication.
1. Set the authentication method for local to trust.
2. Set the authentication method for host to password.
3. Append the following line to the end of the file.
```
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.
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.

OS	Command
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

Configure /etc/hue/conf/hue.ini to use PostgreSQL. Modify these options as appropriate and paste below [[database]] and [desktop]:
```
host=localhost
port=5432
engine=postgresql_psycopg2
user=hue
password=<secretpassword>
name=hue
```

Load any backed up data:

Ensure a logs directory exists and is writable at /opt/cloudera/parcels/CDH/lib/hue/logs.
Ensure the logs directory has hue user and group ownership.

Synchronize and migrate the database.

$ sudo mkdir /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo chown hue:hue /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo -u hue <HUE_HOME>/build/env/bin/hue syncdb --noinput
$ sudo -u hue <HUE_HOME>/build/env/bin/hue migrate

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;

Load the data.

$ sudo -u hue <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json

Add the foreign key:

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;

Configuring the Hue Server to Store Data in Oracle

Ensure Python 2.6 or higher is installed on the server Hue is running on.
Download the Oracle client libraries at Instant Client for Linux x86-64 Version 11.1.0.7.0, Basic and SDK (with headers) zip files to the same directory.
Note: The Oracle 12 instant client is currently not supported. Hue works with the Oracle 12 database, but only with the Oracle 11 client libraries.
Unzip the zip files.

Set environment variables to reference the libraries.

$ export ORACLE_HOME=<download directory>
$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME

Create a symbolic link for the shared object:

$ cd $ORACLE_HOME
$ ln -sf libclntsh.so.11.1 libclntsh.so

Get a data dump by executing:
Note: HUE_HOME is a reference to the location of your Hue installation. For package installs, this is usually /usr/lib/hue; for parcel installs, this is usually, /opt/cloudera/parcels/<parcel version>/lib/hue/.
```
$ <HUE_HOME>/build/env/bin/hue dumpdata > <some-temporary-file>.json --indent 2  
```
Edit the Hue configuration file hue.ini. Directly below the [[database]] section under the [desktop] line, add the following options (and modify accordingly for your setup):
```
host=localhost
port=1521
engine=oracle
user=hue
password=<secretpassword>
name=<SID of the Oracle database, for example, 'XE'>
```
To use the Oracle service name instead of the SID, use the following configuration instead:
```
port=0
engine=oracle
user=hue
password=password
name=oracle.example.com:1521/orcl.example.com
```
The directive port=0 allows Hue to use a service name. The name string is the connect string, including hostname, port, and service name.

To add support for a multithreaded environment, set the threaded option to true under the [desktop]>[[database]] section.
```
options={'threaded':true}
```

Grant required permissions to the Hue user in Oracle:

GRANT CREATE <sequence> TO <user>; 
GRANT CREATE <session> TO <user>; 
GRANT CREATE <table> TO <user>; 
GRANT CREATE <view> TO <user>; 
GRANT CREATE <procedure> TO <user>; 
GRANT CREATE <trigger> TO <user>; 
GRANT EXECUTE ON sys.dbms_crypto TO <user>; 
GRANT EXECUTE ON SYS.DBMS_LOB TO <user>;

As the hue user, configure Hue to load the existing data and create the necessary database tables. You will need to run both the syncdb and migrate commands. When running these commands, Hue will try to access a logs directory, located at /opt/cloudera/parcels/CDH/lib/hue/logs, which might be missing. If that is the case, first create the logs directory and give the hue user and group ownership of the directory.
```
$ sudo mkdir /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo chown hue:hue /opt/cloudera/parcels/CDH/lib/hue/logs
$ sudo -u hue <HUE_HOME>/build/env/bin/hue syncdb --noinput
$ sudo -u hue <HUE_HOME>/build/env/bin/hue migrate
```
Ensure you are connected to Oracle as the hue user, then run the following command to delete all data from Oracle tables:
```
SELECT 'DELETE FROM ' || '.' || table_name || ';' FROM user_tables;   
```
Run the statements generated in the preceding step.
Commit your changes.
```
commit;
```

Load the data.

$ sudo -u hue <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json

Using an External Database for Hue Using Cloudera Manager

Managing Impala