Note:

• If you already have a MariaDB database set up, you can skip to the section Configuring and Starting the MariaDB Server to verify that your MariaDB configurations meet the requirements for Cloudera Manager.
• It is important that the datadir directory, which, by default, is /var/lib/mysql, is on a partition that has sufficient free space.

1. Install the MariaDB database.

   OS	Command
   RHEL	$ sudo yum install mariadb-server
   SLES	$ sudo zypper install mariadb-server   Note: Some SLES systems encounter errors when using the zypper install command. For more information on resolving this issue, see the Novell Knowledgebase topic, error running chkconfig.
   Ubuntu and Debian	$ sudo apt-get install mariadb-server

   After issuing the command to install MariaDB, you might need to confirm that you want to complete the installation.

1. Stop the MariaDB server if it is running.

   $ sudo service mariadb stop

2. Move old InnoDB log files /var/lib/mysql/ib_logfile0 and /var/lib/mysql/ib_logfile1 out of /var/lib/mysql/ to a backup location.
3. Determine the location of the option file, my.cnf.
4. Update my.cnf so that it conforms to the following requirements:
   • To prevent deadlocks, set the isolation level to read committed.
   • The default settings in the MariaDB installations in most distributions use conservative buffer sizes and memory usage. Cloudera Management Service roles need high write throughput because they might insert many records in the database. Cloudera recommends that you set the innodb_flush_method property to O_DIRECT.
   • Set the max_connections property according to the size of your cluster:
     • Small clusters (fewer than 50 hosts) - You can store more than one database (for example, both the Activity Monitor and Service Monitor) on the same host. If you do this, you should:
       • Put each database on its own storage volume.
       • Allow 100 maximum connections for each database and then add 50 extra connections. For example, for two databases, set the maximum connections to 250. If you store five databases on one host (the databases for Cloudera Manager Server, Activity Monitor, Reports Manager, Cloudera Navigator, and Hive metastore), set the maximum connections to 550.
     • Large clusters (more than 50 hosts) - Do not store more than one database on the same host. Use a separate host for each database/host pair. The hosts need not be reserved exclusively for databases, but each database should be on a separate host.
   • Binary logging is not a requirement for Cloudera Manager installations. Binary logging provides benefits such as MariaDB replication or point-in-time incremental recovery after database restore. Examples of this configuration follow. For more information, see The Binary Log.

   Here is an option file with Cloudera recommended settings:

   [mysqld]
   transaction-isolation = READ-COMMITTED
   # Disabling symbolic-links is recommended to prevent assorted security risks;
   # to do so, uncomment this line:
   # symbolic-links = 0
   
   key_buffer = 16M
   key_buffer_size = 32M
   max_allowed_packet = 32M
   thread_stack = 256K
   thread_cache_size = 64
   query_cache_limit = 8M
   query_cache_size = 64M
   query_cache_type = 1
   
   max_connections = 550
   #expire_logs_days = 10
   #max_binlog_size = 100M
   
   #log_bin should be on a disk with enough free space. Replace '/var/lib/mysql/mysql_binary_log' with an appropriate path for your system
   #and chown the specified folder to the mysql user.
   log_bin=/var/lib/mysql/mysql_binary_log
   
   binlog_format = mixed
   
   read_buffer_size = 2M
   read_rnd_buffer_size = 16M
   sort_buffer_size = 8M
   join_buffer_size = 8M
   
   # InnoDB settings
   innodb_file_per_table = 1
   innodb_flush_log_at_trx_commit  = 2
   innodb_log_buffer_size = 64M
   innodb_buffer_pool_size = 4G
   innodb_thread_concurrency = 8
   innodb_flush_method = O_DIRECT
   innodb_log_file_size = 512M
   
   [mysqld_safe]
   log-error=/var/log/mariadb/mariadb.log
   pid-file=/var/run/mariadb/mariadb.pid

5. If AppArmor is running on the host where MariaDB is installed, you might need to configure AppArmor to allow MariaDB to write to the binary.
6. Ensure the MariaDB server starts at boot:

   OS	Command
   RHEL	$ sudo systemctl enable mariadb
   SLES	$ sudo chkconfig --add mariadb
   Ubuntu and Debian	$ sudo chkconfig mariadb on   Note: chkconfig may not be available on recent Ubuntu releases. You may need to use Upstart to configure MariaDB to start automatically when the system boots. For more information, see the Ubuntu documentation or the Upstart Cookbook.

7. Start the MariaDB server:

   $ sudo service mariadb start

8. Set the MariaDB root password. In the following example, the 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
    ... Success!

The MariaDB JDBC driver is not supported. Follow the steps in this section to install and use the MySQL JDBC driver instead.

Install the JDBC driver on the Cloudera Manager Server host, as well as hosts to which you assign the Activity Monitor, Reports Manager, Hive Metastore Server, Hue Server, Sentry Server, Cloudera Navigator Audit Server, and Cloudera Navigator Metadata Server roles.

Cloudera recommends that you assign all roles that require databases on the same host and install the driver on that host. Locating all such roles on the same host is recommended but not required. If you install a role, such as Activity Monitor, on one host and other roles on a separate host, you would install the JDBC driver on each host running roles that access the database.

OS	Command
RHEL	Important: Do not use the yum install command to install the MySQL driver package, because it installs openJDK, and then uses the Linux alternatives command to set the system JDK to be openJDK. Download the MySQL JDBC driver from http://www.mysql.com/downloads/connector/j/5.1.html. Extract the JDBC driver JAR file from the downloaded file. For example: tar zxvf mysql-connector-java-5.1.31.tar.gz Copy the JDBC driver, renamed, to the relevant host. For example: $ sudo cp mysql-connector-java-5.1.31/mysql-connector-java-5.1.31-bin.jar /usr/share/java/mysql-connector-java.jar If the target directory does not yet exist on this host, you can create it before copying the JAR file. For example: $ sudo mkdir -p /usr/share/java/ $ sudo cp mysql-connector-java-5.1.31/mysql-connector-java-5.1.31-bin.jar /usr/share/java/mysql-connector-java.jar
SLES	$ sudo zypper install mysql-connector-java
Ubuntu or Debian	$ sudo apt-get install libmysql-java

To install and configure MariaDB for Hue, see, see Connect Hue to MySQL or MariaDB.