=====Overview=====
  * 192.168.0.100 mysqlndbmgm
  * 192.168.0.110 mysqldatanodea
  * 192.168.0.120 mysqldatanodeb
  * 192.168.0.210 mysqlsqlnodea
  * 192.168.0.220 mysqlsqlnodeb

====MySQL NDB Cluster Architecture:====
MySQL NDB Cluster has 3 major components:

  * Management Node
  * SQL Node
  * Data Node

We will discuss each of these 3 components in turn:

====Management Node====

The Cluster management server is used to manage the other node of the cluster. We can create and configure new nodes, restart, delete, or backup nodes on the cluster from the management node. In nutshell, the management node is used to control the cluster engine and observe it as a monitoring tool:

Installing the management node binaries:
<sxh bash>
[root@mysqlndbmgm ~]# rpm -Uvh mysql-cluster-community-management-server-7.5.7-1.el7.x86_64.rpm
Preparing...                          ################################# [100%]
        package mysql-cluster-community-management-server-7.5.7-1.el7.x86_64 is already installed
[root@mysqlndbmgm ~]#
</sxh>


Configuration:

<sxh bash>
[root@mysqlndbmgm mysql-cluster]# cat >> /var/lib/mysql-cluster/config.ini << EOF
[ndb_mgmd default]
# Directory for MGM node log files
DataDir=/var/lib/mysql-cluster

[ndb_mgmd]
#Management Node db1
HostName=192.168.0.100

[ndbd default]
NoOfReplicas=2      # Number of replicas
DataMemory=64M     # Memory allocate for data storage
IndexMemory=64M    # Memory allocate for index storage
#Directory for Data Node
DataDir=/var/lib/mysql-cluster

[ndbd]
#Data Node db2
HostName=192.168.0.110

[ndbd]
#Data Node db3
HostName=192.168.0.120

[mysqld]
#SQL Node db4
HostName=192.168.0.210

[mysqld]
#SQL Node db5
HostName=192.168.0.220
[root@mysqlndbmgm mysql-cluster]#
EOF
</sxh>

Starting:
<sxh bash>
ndb_mgmd --config-file=/var/lib/mysql-cluster/config.ini
</sxh>
Show configuration:
<sxh bash>
[root@mysqlsqlnodea ~]# ndb_mgm
-- NDB Cluster -- Management Client --
ndb_mgm> show
Connected to Management Server at: 192.168.0.100:1186
Cluster Configuration
---------------------
[ndbd(NDB)]     2 node(s)
id=2    @192.168.0.110  (mysql-5.7.19 ndb-7.5.7, Nodegroup: 0, *)
id=3    @192.168.0.120  (mysql-5.7.19 ndb-7.5.7, Nodegroup: 0)

[ndb_mgmd(MGM)] 1 node(s)
id=1    @192.168.0.100  (mysql-5.7.19 ndb-7.5.7)

[mysqld(API)]   2 node(s)
id=4    @192.168.0.210  (mysql-5.7.19 ndb-7.5.7)
id=5    @192.168.0.220  (mysql-5.7.19 ndb-7.5.7)

ndb_mgm>

</sxh>


====SQL Node====

The interface servers that are used by the applications to connect to the database cluster. This is where the mysqld is started and the databases are available.

Installation:
<sxh bash>
[root@mysqlsqlnodea ~]# rpm -Uvh mysql-cluster-community-server-7.5.7-1.el7.x86_64.rpm
warning: mysql-cluster-community-server-7.5.7-1.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing...                          ################################# [100%]
        package mysql-cluster-community-server-7.5.7-1.el7.x86_64 is already installed
[root@mysqlsqlnodea ~]#
</sxh>

Configuration:
<sxh bash>
cat >> /etc/my.cnf << EOF

[mysqld]
ndb-connectstring=192.168.0.100:1186
ndb-nodeid=N
ndbcluster
datadir=/var/lib/mysql/data
basedir=/var/lib/mysql
server-id=N
log-bin

[mysql_cluster]
ndb-connectstring=192.168.0.100
EOF
</sxh>


Starting a SQL Node:

<sxh bash>
service mysqld start
</sxh>

or on Linux 7+
<sxh bash>
systemctl start mysql
</sxh>

====Data Node====

This is the layer where the process of synchronizing and data replication between nodes happens.

Installing the data node:
<sxh bash>
[root@mysqldatanodea ~]# rpm -Uvh mysql-cluster-community-data-node-7.5.7-1.el7.x86_64.rpm
Preparing...                          ################################# [100%]
        package mysql-cluster-community-data-node-7.5.7-1.el7.x86_64 is already installed
</sxh>

Configuration:
<sxh bash>
[root@mysqldatanodea ~]# cat >> /etc/my.cnf << EOF
[mysqld]
ndbcluster
ndb-connectstring=192.168.0.100     # IP address of Management Node

[mysql_cluster]
ndb-connectstring=192.168.0.100   # IP address of Management Node
EOF
</sxh>

Starting NDB Data node
<sxh bash>
[root@mysqldatanodea ~]# ndbd
2017-10-17 11:13:58 [ndbd] INFO     -- Angel connected to '192.168.0.100:1186'
2017-10-17 11:13:58 [ndbd] INFO     -- Angel allocated nodeid: 2
[root@mysqldatanodea ~]#
</sxh>