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. To configure Hue with any of the supported external databases, the high-level steps are:
  1. Stop Hue service.
  2. Backup default SQLite database.
  3. Install database software and dependencies.
  4. Create and configure database and load data.
  5. Start Hue service.
See the tasks on this page for details. If you don't need to migrate a SQLite database, you can skip the steps on dumping the database and editing the JSON objects.

Prerequisites

Before using an external database with Hue, install all of the support libraries required by your operating system. See Development Preferences in the Hue documentation for the full list.

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 used by Hue is located in /var/lib/hue/desktop.db. You can inspect this database from the command line using 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 database, SQLite, cannot support large data migrations. Hue supports MariaDB, MySQL, PostgreSQL, and Oracle. See Supported Databases for the supported versions.

In the instructions that follow, dumping the database and editing the JSON objects is only necessary if you have data in SQLite that you need to migrate. If you do not need to migrate data from SQLite, you can skip those steps.

Configuring the Hue Server to Store Data in MariaDB

  1. Shut down the Hue server if it is running.
  2. 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"
        }
      },
    .....
  3. Start the Hue server.
  4. 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
  5. 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
  6. 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
  7. 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
  8. Start the MariaDB daemon.
    $ sudo service mariadb start
  9. 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!
  10. 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
  11. 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)
  12. Open the Hue configuration file in a text editor.
  13. 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
  14. 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.
    $ 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;
  15. (InnoDB only) Drop the foreign key.
    mysql > ALTER TABLE auth_permission DROP FOREIGN KEY content_type_id_refs_id_XXXXXX;
  16. Delete the rows in the django_content_type table.
    mysql > DELETE FROM hue.django_content_type;
  17. Load the data.
    $ <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json
  18. (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

  1. Shut down the Hue server if it is running.
  2. Dump the existing database data to a text file. Note that using the .json extension is required.
    $ sudo -u hue <HUE_HOME>/build/env/bin/hue dumpdata > <some-temporary-file>.json
  3. 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"
        }
      },
    .....
  4. Start the Hue server.
  5. 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
  6. 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
  7. Install and start MySQL.
    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
  8. 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
  9. Start the mysql daemon.
    OS Command

    RHEL

    $ sudo service mysqld start

    SLES and Ubuntu or Debian

    $ sudo service mysql start
  10. Configure MySQL 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!
  11. 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
  12. 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)
  13. Open the Hue configuration file in a text editor.
  14. 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
  15. 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.
    $ 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;
  16. (InnoDB only) Drop the foreign key.
    mysql > ALTER TABLE auth_permission DROP FOREIGN KEY content_type_id_refs_id_XXXXXX;
  17. Delete the rows in the django_content_type table.
    mysql > DELETE FROM hue.django_content_type;
  18. Load the data.
    $ <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json
  19. (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 PostgreSQL

  1. Shut down the Hue server if it is running.
  2. Dump the existing database data to a text file. Note that using the .json extension is required.
    $ sudo -u hue <HUE_HOME>/build/env/bin/hue dumpdata > <some-temporary-file>.json
  3. 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"
        }
      },
    .....
  4. Install required packages.
    OS Command

    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
  5. Install the module that provides the connector to PostgreSQL.
    sudo -u hue <HUE_HOME>/build/env/bin/pip install setuptools
    sudo -u hue <HUE_HOME>/build/env/bin/pip install psycopg2
  6. 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
  7. Initialize the data directories:
    $ service postgresql initdb
  8. 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
  9. Start the PostgreSQL server.
    $ su - postgres
    # /usr/bin/postgres -D /var/lib/pgsql/data > logfile 2>&1 &
  10. 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
  11. 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
  12. Restart the PostgreSQL server.
    $ sudo service postgresql restart
  13. Verify connectivity.
    psql -h localhost -U hue -d hue 
    Password for user hue: <secretpassword>
  14. 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
  15. Open the Hue configuration file in a text editor.
  16. 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=5432
    engine=postgresql_psycopg2
    user=hue
    password=<secretpassword>
    name=hue
  17. As the hue user, configure Hue to load the existing data and create the necessary database tables. You will need to run both the migrate and syncdb 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
  18. Determine the foreign key ID.
    bash# su - postgres
    $ psql -h localhost -U hue -d hue
    postgres=# \d auth_permission; 
  19. Drop the foreign key that you retrieved in the previous step.
    postgres=# ALTER TABLE auth_permission DROP CONSTRAINT content_type_id_refs_id_<XXXXXX>;
  20. Delete the rows in the django_content_type table.
    postgres=# TRUNCATE django_content_type CASCADE;
  21. Load the data.
    $ sudo -u hue <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json
  22. 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;

Configuring the Hue Server to Store Data in Oracle

  1. Ensure Python 2.6 or higher is installed on the server Hue is running on.
  2. 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.
  3. Unzip the zip files.
  4. Set environment variables to reference the libraries.
    $ export ORACLE_HOME=<download directory>
    $ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME 
  5. Create a symbolic link for the shared object:
    $ cd $ORACLE_HOME
    $ ln -sf libclntsh.so.11.1 libclntsh.so
  6. Get a data dump by executing:
    $ <HUE_HOME>/build/env/bin/hue dumpdata > <some-temporary-file>.json --indent 2  
  7. 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}
  8. 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>;
  9. 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
  10. 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;   
  11. Run the statements generated in the preceding step.
  12. Commit your changes.
    commit;
  13. Load the data.
    $ sudo -u hue <HUE_HOME>/build/env/bin/hue loaddata <some-temporary-file>.json