Cloudera Docs

Install and Configure MariaDB for Cloudera Software

To use a MariaDB database, follow these procedures. For information on compatible versions of MariaDB, see Database Requirements.

Installing MariaDB Server

  1. Install MariaDB server:
    OS Command
    RHEL compatible 
    sudo yum install mariadb-server
    SLES 
    sudo zypper install mariadb-server
    Ubuntu 
    sudo apt-get install mariadb-server
    If these commands do not work, you might need to add a repository or use a different yum install command, particularly on RHEL 6 compatible operating systems. For more assistance, see the following topics on the MariaDB website:

Configuring and Starting the MariaDB Server

  1. Stop the MariaDB server if it is running:
    OS Command
    RHEL 7 Compatible, SLES, and Ubuntu 
    sudo systemctl stop mariadb
  2. If they exist, 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 (/etc/my.cnf by default).
  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:
      • Fewer than 50 hosts - You can store more than one database (for example, both the Cloudera Manager Server and Reports Manager) on the same host. If you do this, you should:
        • Put each database on its own physical disk for best performance. You can do this by manually setting up symbolic links or running multiple database instances (each instance uses a different data directory path).
        • 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 four databases on one host (the databases for Cloudera Manager Server, Hue, Reports Manager, and Hive metastore), set the maximum connections to 450.
      • 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 do not need to be reserved exclusively for databases, but each database should be on a separate host.
    • If the cluster has more than 1000 hosts, set the max_allowed_packet property to 16M. Without this setting, the cluster may fail to start due to the following exception: com.mysql.jdbc.PacketTooBigException.
    • Although binary logging is not a requirement for Cloudera Manager installations, it provides benefits such as MariaDB replication or point-in-time incremental recovery after a database restore. The provided example configuration enables the binary log. For more information, see The Binary Log.

    Here is an option file with Cloudera recommended settings:

    [mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
transaction-isolation = READ-COMMITTED
# Disabling symbolic-links is recommended to prevent assorted security risks;
# to do so, uncomment this line:
symbolic-links = 0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd

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

#In later versions of MariaDB, if you enable the binary log and do not set
#a server_id, MariaDB will not start. The server_id must be unique within
#the replicating group.
server_id=1

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

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d
  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 7 compatible, SLES, and Ubuntu 
    sudo systemctl enable mariadb
  7. Start the MariaDB server:
    OS Command
    RHEL 7 compatible, SLES, and Ubuntu 
    sudo systemctl start mariadb
  8. Run /usr/bin/mysql_secure_installation to set the MariaDB root password and other security-related settings. In a new installation, the root password is blank. Press the Enter key when you're prompted for the root password. For the rest of the prompts, enter the responses listed below in bold:
    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!  If you've completed all of the above steps, your MariaDB
installation should now be secure.

Thanks for using MariaDB!

Installing the MySQL JDBC Driver for MariaDB

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 any other hosts running services that require database access.

Cloudera recommends that you consolidate all roles that require databases on a limited number of hosts, and install the driver on those hosts. Locating all such roles on the same hosts is recommended but not required. Make sure to install the JDBC driver on each host running roles that access the database.
OS Command
RHEL
  1. Download the MySQL JDBC driver from http://www.mysql.com/downloads/connector/j/5.1.html (in .tar.gz format). As of the time of writing, you can download version 5.1.48 using wget as follows:
    wget https://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-java-5.1.48.tar.gz
  2. Extract the JDBC driver JAR file from the downloaded file. For example:
    tar zxvf mysql-connector-java-5.1.48.tar.gz
  3. Copy the JDBC driver, renamed, to /usr/share/java/. If the target directory does not yet exist, create it. For example:
    sudo mkdir -p /usr/share/java/
cd mysql-connector-java-5.1.48
sudo cp mysql-connector-java-5.1.48-bin.jar /usr/share/java/mysql-connector-java.jar
SLES 
sudo zypper install mysql-connector-java
Ubuntu 
sudo apt-get install libmysql-java

Creating Databases for Cloudera Software

Services that require databases

Create databases and service accounts for components that require databases:

  • Cloudera Manager Server
  • Cloudera Management Service roles:
    • Reports Manager
  • Data Analytics Studio (DAS) Supported with PostgreSQL only.
  • Hue
  • Each Hive metastore
  • Oozie
  • Data Analytics Studio
  • Schema Registry
  • Streams Messaging Manager

Steps

  1. Log in as the root user, or another user with privileges to create database and grant privileges:
    mysql -u root -p
    Enter password:
  2. Create databases for each service deployed in the cluster using the following commands. You can use any value you want for the <database>, <user>, and <password> parameters. The Databases for Cloudera Software table, below lists the default names provided in the Cloudera Manager configuration settings, but you are not required to use them.

    Configure all databases to use the utf8 character set.

    Include the character set for each database when you run the CREATE DATABASE statements described below.

    CREATE DATABASE <database> DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;
    Query OK, 1 row affected (0.00 sec)

    Create USER by following the steps in this topic: CREATE USER Statement.

    GRANT ALL ON <database>.* TO '<user>'@'%' IDENTIFIED BY '<password>';
    Query OK, 0 rows affected (0.00 sec)
    Table 1. Databases for Cloudera Software
    Service Database User
    Cloudera Manager Server scm scm
    Reports Manager rman rman
    Ranger RHEL/CentOS/Ubuntu ranger rangeradmin
    Ranger KMS RHEL/CentOS ranger rangerkms
    Hue hue hue
    Hive Metastore Server hive hive
    Oozie oozie oozie
    Data Analytics Studio (DAS) Supported with PostgreSQL only. das das
    Schema Registry schemaregistry schemaregistry
    Streams Messaging Manager smm smm
  3. Confirm that you have created all of the databases:
    SHOW DATABASES;
    You can also confirm the privilege grants for a given user by running:
    SHOW GRANTS FOR '<user>'@'%';
  4. Record the values you enter for database names, usernames, and passwords. The Cloudera Manager installation wizard requires this information to correctly connect to these databases.

Next Steps