MySQL Cluster Tutorial - cdn.oreillystatic.com

Administer MySQL Cluster
MySQL Cluster has a command line tool to talk directly to the management server to
obtain information and execute basic functions. It also has a verbose logging system which
can help diagnose many problems with the cluster.
NDB_MGM
A key tool for running basic administration tasks is ndb_mgm. This is a command line tool to
send basic commands to the cluster. It communicates to the management nodes using an
unsecured port with no authentication (take note this should be done behind a firewall or
private network).
To invoke this tool simply run:
shell> ndb_mgm
If you are not running it locally to the management node then you will need to give it a
connect string:
shell> ndb_mgm --ndb-connectstring=192.168.1.10
You can also execute a one-time command with this tool rather than getting a command
prompt using:
shell> ndb_mgm -e 'SHOW'
Commands in ndb_mgm almost all follow a common syntax. Many commands require
node IDs, some do not, so the syntax is typically as follows:
ndb_mgm> [node_id] {command} [parameters]
The node_id can be any single node ID or the keyword 'ALL' to send it to all data nodes.
Common Commands
SHOW
This command gives a quick overview of the status of all the nodes, whether or not they are
connected and up/down.
For example:
ndb_mgm> show
Cluster Configuration
---------------------
[ndbd(NDB)] 2 node(s)
id=2 @127.0.0.1 (mysql-5.1.41 ndb-7.1.2, Nodegroup: 0, Master)
id=3 @127.0.0.1 (mysql-5.1.41 ndb-7.1.2, Nodegroup: 0)
[ndb_mgmd(MGM)] 1 node(s)
id=1 @127.0.0.1 (mysql-5.1.41 ndb-7.1.2)
[mysqld(API)] 2 node(s)
id=4 @127.0.0.1 (mysql-5.1.41 ndb-7.1.2)
id=5 (not connected, accepting connect from any host)
If the data nodes are currently starting you will see this reflected in this status as follows:
[ndbd(NDB)] 2 node(s)
id=2 @127.0.0.1 (mysql-5.1.41 ndb-7.1.2, starting, Nodegroup: 0, Master)
id=3 @127.0.0.1 (mysql-5.1.41 ndb-7.1.2, starting, Nodegroup: 0)
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