Note:

• If you already have a MySQL database set up, you can skip to the section Configuring and Starting the MySQL Server to verify that your MySQL 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 MySQL database.

   OS	Command
   RHEL	$ sudo yum install mysql-server
   SLES	$ sudo zypper install mysql $ sudo zypper install libmysqlclient_r15   Note: Some SLES systems encounter errors when using the preceding 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 mysql-server

   After issuing the command to install MySQL, you may need to respond to prompts to confirm that you do want to complete the installation.

1. Determine the version of MySQL.
2. Stop the MySQL server if it is running.

   OS	Command
   RHEL	$ sudo service mysqld stop
   SLES, Ubuntu, and Debian	$ sudo service mysql stop

3. 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.
4. Determine the location of the option file, my.cnf.
5. Update my.cnf so that it conforms to the following requirements:
     Important:

   • To prevent deadlocks, Cloudera Manager requires the isolation level to be set to read committed.
   • Configure the InnoDB engine. Cloudera Manager will not start if its tables are configured with the MyISAM engine. (Typically, tables revert to MyISAM if the InnoDB engine is misconfigured.) To check which engine your tables are using, run the following command from the MySQL shell:

     mysql> show table status;

   • The default settings in the MySQL installations in most distributions are very conservative with regards to buffer sizes and memory usage. Cloudera Management Service roles need high write throughput as, based on cluster size, they may insert a lot of records in the database. Therefore 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. Clusters with fewer than 50 hosts can be considered small clusters and clusters with more than 50 hosts can be considered large clusters:
     • Small clusters - 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 - do not store more than one database on the same host. In such a case, 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.
   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
   
   # log-bin should be on a disk with enough free space
   # NOTE: replace '/x/home/mysql/logs/binary' below with
   #       an appropriate path for your system.
   log-bin=/x/home/mysql/logs/binary/mysql_binary_log
   
   # For MySQL version 5.1.8 or later. Comment out binlog_format for older versions.
   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/mysqld.log
   pid-file=/var/run/mysqld/mysqld.pid

6. If AppArmor is running on the host where MySQL is installed, you might need to configure AppArmor to allow MySQL to write to the binary.
7. Ensure the MySQL server starts 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 and Debian	$ sudo chkconfig mysql on   Note: chkconfig may not be available on recent Ubuntu releases. In such cases, you may need to use Upstart to configure MySQL to start automatically when the system boots. See the Ubuntu documentation or the Upstart Cookbook for more information.

8. Start the MySQL server:

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

9. Set the MySQL root 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!

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

  Note: If you already have the JDBC connector installed on the hosts that need it, you can skip this section.

$ sudo yum install mysql-connector-java

$ sudo zypper install mysql-connector-java

$ sudo apt-get install libmysql-java