4.2.1 Starting and Stopping the Agent on Linux

To start the MySQL Cluster Manager agent on a given host running a Linux or similar operating system, you should run mcmd, found in the bin directory within the manager installation directory on that host. Typical options used with mcmd are shown here:

mcmd [--config=filename | --bootstrap]

See Section 4.1, “mcmd, the MySQL Cluster Manager Agent”, for information about additional options that can be used when invoking mcmd from the command line, or in a configuration file.

mcmd normally runs in the foreground. If you wish, you can use your platform's usual mechanism for backgrounding a process. On a Linux system, you can do this by appending an ampersand character (&), like this (not including any options that might be required):

$> ./bin/mcmd &

By default, the agent assumes that the agent configuration file is mcmd.conf in the MySQL Cluster Manager installation directory (see Section 3.4, “MySQL Cluster Manager Configuration File” for more details). You can tell the agent to use a different configuration file by passing the path to this file to the --config option, as shown here:

$> ./bin/mcmd --config=/home/mcm/mcm-agent.conf

The --bootstrap option causes the agent to start with default configuration values, create a default one-machine cluster named mycluster, and start it. This option works only if no sites have been created yet.

The use of the --bootstrap option with mcmd is shown here on a system having the host name torsk, where MySQL Cluster Manager has been installed to /home/jon/mcm:

$> ./mcmd --bootstrap
logging facility initialized, switching logging to loggers specified in configuration
MySQL Cluster Manager 8.0.40 (64bit) started
Connect to MySQL Cluster Manager by running "/home/clusteradmin/mcm8.0.40/bin/mcm" -h torsk -P 1862
Configuring default cluster 'mycluster'...
Setting default_storage_engine to ndbcluster...
Starting default cluster 'mycluster' version '8.0.40-cluster'...
Cluster 'mycluster' started successfully
	ndb_mgmd           torsk:1186
	ndbmtd		torsk
	ndbmtd		torsk
	mysqld		torsk:3306
	mysqld		torsk:3307
	ndbapi		*
Connect to the database by running "/home/clusteradmin/cluster/bin/mysql" -h 127.0.0.1 -P 3306 -u root

You can then connect to the agent using the mcm client (see Section 4.3, “Starting the MySQL Cluster Manager Client”), and to either of the MySQL Servers running on ports 3306 and 3307 using mysql or another MySQL client application.

See Section 4.1, “mcmd, the MySQL Cluster Manager Agent”, for more information about options that can be used with mcmd.

The MySQL Cluster Manager agent must be started on each host in the MySQL NDB Cluster to be managed.

To stop one or more instances of the MySQL Cluster Manager agent, use the stop agents command in the MySQL Cluster Manager client. If the client is unavailable, you can stop each agent process using the system's standard method for doing so, such as ^C or kill.

You can also set the agent up as a daemon or service on Linux and other Unix-like systems. (See Section 3.3.1, “Installing MySQL Cluster Manager on Unix-like Platforms”.) If you also want data node failed processes from a running MySQL NDB Cluster to be started when the agent fails and restarts in such cases, you must make sure that StopOnError is set to 0 on each data node (and not to 1, the default).