MySQL Cluster: Problem Connecting the SQL node

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 they connect to the manager 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 recognizing each machine as only 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

ps -ef | grep mysqld | grep -v grep

Output of: ps -ef | grep mysqld | grep -v grep

• sswahn: I have tried variations to this install. All nodes on separate hosts, mysql/data on same host, mysql/data/manager... Always the problem is connecting the SQL node.

Answer 1

So the solution was the conflicting myslqd. Apparently mysql has a mysqld and mysql cluster has a mysqld and they were conflicting or I was running the wrong one. In the end I uninstalled mysql and reinstalled mysql cluster and it worked perfectly. Big thanks to RolandoMySQLDBA for helping me troubleshoot this issue.

Answer 2

/* This query will return number of not running nodes , returns 0 incase of all nodes are running*/

SELECT 
 @total := 
 (SELECT 
 VARIABLE_VALUE 
 FROM
 information_schema.`GLOBAL_STATUS` 
 WHERE VARIABLE_NAME = 'NDB_NUMBER_OF_DATA_NODES') AS `Total`,
 @running := 
 (SELECT 
 VARIABLE_VALUE 
 FROM
 information_schema.`GLOBAL_STATUS` 
 WHERE VARIABLE_NAME = 'NDB_NUMBER_OF_READY_DATA_NODES') AS `Running`,
 @total - @running AS `Nodes_Not_Running` ;

What does this query returns?

Only %Ndb_number_of_ready_data_nodes% out of %Ndb_number_of_data_nodes% data nodes are running. View which data nodes are unavailable by running ndb_mgm -e show