The management server is the process that reads the cluster configuration file and distributes this information to all nodes in the cluster that request it. It also maintains a log of cluster activities. Management clients can connect to the management server and check the cluster's status.
The following table includes command options specific to the MySQL Cluster management server program ndb_mgmd. Additional descriptions follow the table. For options common to all MySQL Cluster programs, see Section 15.4.20, “Options Common to MySQL Cluster Programs — Options Common to MySQL Cluster Programs”.
Table 15.10 ndb_mgmd Command Line Options
|-f||Specify the cluster configuration file; in NDB-6.4.0 and later, needs --reload or --initial to override configuration cache if present|
|--daemon||Run ndb_mgmd in daemon mode (default)|
|--interactive||Run ndb_mgmd in interactive mode (not officially supported in production; for testing purposes only)|
|--mycnf||Read cluster configuration data from the my.cnf file|
|--no-nodeid-checks||Do not provide any node id checks|
|--nodaemon||Do not run ndb_mgmd as a daemon|
|--print-full-config||Print full configuration and exit||4.1.14|
|Command-Line Format||from 4.1.8|
|Permitted Values (>= 4.1.8)|
Instructs the management server as to which file it should
use for its configuration file. By default, the management
server looks for a file named
config.ini in the same directory as the
ndb_mgmd executable; otherwise the file
name and location must be specified explicitly.
-f shortcut is available beginning with
MySQL Cluster 4.1.8. This option also can be given as
but this shortcut is obsolete and should
not be used in new installations.
Instructs ndb_mgmd to start as a daemon process. This is the default behavior.
Instructs ndb_mgmd not to start as a daemon process.
Shows extended information regarding the configuration of
the cluster. With this option on the command line the
ndb_mgmd process prints information about
the cluster setup including an extensive list of the cluster
configuration sections as well as parameters and their
values. Normally used together with the
As of MySQL 4.1.5, it is no longer necessary to specify a connectstring when starting the management server. However, if you are using more than one management server, a connectstring should be provided and each node in the cluster should specify its node ID explicitly.
See Section 18.104.22.168, “The MySQL Cluster Connectstring”, for information about using connectstrings. Section 15.4.20, “Options Common to MySQL Cluster Programs — Options Common to MySQL Cluster Programs”, describes other options for ndb_mgmd.
The following files are created or used by
ndb_mgmd in its starting directory. From
MySQL 4.1.5, the log and PID files are placed in the
DataDir as specified in the
config.ini configuration file. In the list
node_id is the unique
config.ini is the configuration file
for the cluster as a whole. This file is created by the user
and read by the management server.
Section 15.3, “MySQL Cluster Configuration”, discusses how
to set up this file.
cluster.log in version 4.1.3) is
the cluster events log file. Examples of such events include
checkpoint startup and completion, node startup events, node
failures, and levels of memory usage. A complete listing of
cluster events with descriptions may be found in
Section 15.5, “Management of MySQL Cluster”.
When the size of the cluster log reaches one million bytes,
the file is renamed to
in version 4.1.3) where
the sequence number of the cluster log file. (For example:
If files with the sequence numbers 1, 2, and 3 already
exist, the next log file is named using the number
node1.out in version 4.1.3) is the
file used for
stderr when running the management server
as a daemon.
in version 4.1.3) is the process ID file used when running
the management server as a daemon.