Question

In a MySQL cluster I have three hosts, one with a manager node, and the other two are each both a data node and sql node. Connecting to the manager is possible, however only as [ndbd] and not [mysqld]… Meaning the manager sees them as data nodes but not as sql nodes. Everything looks as it should other than the “not connected” part, and I receive no error messages. So my question is why is the manager node only recognizing each machine as a data node and not as mysql node as well?

Below you can see the ndb_mgm cluster configuration followed by the contents of config.ini:

    Cluster Configuration
    ---------------------
    [ndbd(NDB)]     2 node(s)
    id=2     @10.0.40.105    (mysql-5.5.25 ndb-7.2.7, Nodegroup: 0, Master)
    id=3     @10.0.40.100    (mysql-5.5.25 ndb-7.2.7, Nodegroup: 0)

    [ndb_mgmd(MGM)] 1 node(s)
    id=1     @10.0.40.119    (mysql-5.5.25 ndb-7.2.7)

    [mysqld(API)]   2 node(s)
    id=4 (not connected, accepting connect from any host)
    id=5 (not connected, accepting connect from any host)

config.ini:

    [ndbd default]
    # Options affecting ndbd processes on all data nodes:
    NoOfReplicas=2    # Number of replicas

    [tcp default]
    # TCP/IP options:

    [ndb_mgmd]
    # Management process options:
    hostname=10.0.40.119          # Hostname or IP address of MGM node
    datadir=/var/lib/mysql-cluster  # Directory for MGM node log files
    NodeId=1

    [ndbd]
    # Options for data node-1:
                                    # (one [ndbd] section per data node)
    hostname=10.0.40.105            # Hostname or IP address
    datadir=/usr/local/mysql/data   # Directory for this data node's data files
    NodeId=2

    [ndbd]
    # Options for data node-2:
    hostname=10.0.40.100           # Hostname or IP address
    datadir=/usr/local/mysql/data   # Directory for this data node's data files
    NodeId=3

    #one [mysqld] per storage node
    [mysqld]
    [mysqld]

/etc/my.cnf:

[mysqld]
ndbcluster
ndb-connectstring=10.0.40.119

[mysql_cluster]
ndb-connectstring=10.0.40.119

I have some confusion about starting mysqld. The process I go through to start each node is as follows:

ndb_mgmd:

ndb_mgmd --initial --skip-config-cache -f /var/lib/mysql-cluster/config.ini

ndb_mgm

ndbd/mysqld:

ndbd --initial

/etc/init.d/mysql.server start

Answer 1

You haven’t shown your my.cnf file for your mysqlds but my guess is that you’re missing one of the following 2 lines from its [mysqld] section:

ndbcluster

ndb-connectstring=10.0.40.119:1186

OK – so you’ve defined those parameters in your my.cnf file.

Next thing to check – are you using the mysqld that came with MySQL Cluster (i.e. not a ‘regular’ mysqld – which isn’t supported)?

Try starting the mysqld with the --verbose option and see if there are more clues. Take a look at the Cluster log (should be on 10.0.40.119 in the /var/lib/mysql-cluster folder. Take a look any log entries generated by the mysqld.