I have plan to create MySQL cluster with 2 management nodes. If you read my article before regarding MySQL cluster, we are just using one management node. How about if we require more management node in case the primary management node require maintenance or shutdown.
The configuration is different this time. It is because, there are two management nodes. And also this time, I will be using 10 servers. 2 management nodes, 4 data node and 4 MySQL node. For the purpose of simulation, I will be using VMware.
For easier administration, I will be defining the server hostname because I can just use hostname in the config. I will just to edit /etc/hosts file for all 10 servers.
192.168.0.240 ctrl1 ctrl1.inertz.org 192.168.0.231 ctrl2 ctrl2.inertz.org 192.168.0.232 meta1 meta1.inertz.org 192.168.0.233 meta2 meta2.inertz.org 192.168.0.234 meta3 meta3.inertz.org 192.168.0.235 meta4 meta4.inertz.org 192.168.0.236 mysql1 mysql1.inertz.org 192.168.0.237 mysql2 mysql2.inertz.org 192.168.0.238 mysql3 mysql3.inertz.org 192.168.0.239 mysql4 mysql4.inertz.org
The running server now is working like this;
[root@ctrl1 ~]# ndb_mgm -e show Connected to Management Server at: localhost:1186 Cluster Configuration --------------------- [ndbd(NDB)] 4 node(s) id=3 @192.168.0.232 (mysql-8.0.21 ndb-8.0.21, Nodegroup: 0, *) id=4 @192.168.0.233 (mysql-8.0.21 ndb-8.0.21, Nodegroup: 0) id=5 @192.168.0.234 (mysql-8.0.21 ndb-8.0.21, Nodegroup: 1) id=6 @192.168.0.235 (mysql-8.0.21 ndb-8.0.21, Nodegroup: 1) [ndb_mgmd(MGM)] 2 node(s) id=1 @192.168.0.240 (mysql-8.0.21 ndb-8.0.21) id=2 @192.168.0.231 (mysql-8.0.21 ndb-8.0.21) [mysqld(API)] 4 node(s) id=7 @192.168.0.236 (mysql-8.0.21 ndb-8.0.21) id=8 @192.168.0.237 (mysql-8.0.21 ndb-8.0.21) id=9 @192.168.0.238 (mysql-8.0.21 ndb-8.0.21) id=10 @192.168.0.239 (mysql-8.0.21 ndb-8.0.21)
The configuration is basically the same, you just have to add the node required.
[ndb_mgmd default] # Directory for MGM node log files DataDir=/var/lib/mysql-cluster [ndb_mgmd] #Management Node 1 NodeId=1 HostName=ctrl1 [ndb_mgmd] #Management Node 2 NodeId=2 HostName=ctrl2 [ndbd default] NoOfReplicas=2 # Number of replicas DataMemory=256M # Memory allocate for data storage IndexMemory=128M # Memory allocate for index storage #Directory for Data Node DataDir=/var/lib/mysql-cluster [ndbd] #Data Node db1 HostName=192.168.0.232 [ndbd] #Data Node db2 HostName=192.168.0.233 [ndbd] #Data Node db3 HostName=192.168.0.234 [ndbd] #Data Node db4 HostName=192.168.0.235 [mysqld] #SQL Node db1 HostName=192.168.0.236 [mysqld] #SQL Node db2 HostName=192.168.0.237 [mysqld] #SQL Node db3 HostName=192.168.0.238 [mysqld] #SQL Node db4 HostName=192.168.0.239
What is the different this time is how we start the master node.
The configuration for the master node is below;
[root@ctrl1 mysql-cluster]# cat /etc/init.d/ndb_mgmd
#!/bin/bash
# chkconfig: 345 99 01
# description: MySQL Cluster management server start/stop script
STARTMGM="ndb_mgmd -c ctrl1 --ndb-nodeid=1 --config-file=/var/lib/mysql-cluster/config.ini --configdir=/var/lib/mysql-cluster --initial"
start() {
$STARTMGM
}
stop() {
killall -15 ndb_mgmd
sleep 1
killall -9 ndb_mgmd
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart|reload)
stop
start
RETVAL=$?
;;
*)
echo $"Usage: $0 {start|stop|restart}"
exit 1
esac
[root@ctrl1 mysql-cluster]#
And for the second controller, we use the config below;
[root@ctrl2 ~]# cat /etc/init.d/ndb_mgmd
#!/bin/bash
# chkconfig: 345 99 01
# description: MySQL Cluster management server start/stop script
STARTMGM="ndb_mgmd -c ctrl2 --ndb-nodeid=2 --configdir=/var/lib/mysql-cluster"
start() {
$STARTMGM
}
stop() {
killall -15 ndb_mgmd
sleep 1
killall -9 ndb_mgmd
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart|reload)
stop
start
RETVAL=$?
;;
*)
echo $"Usage: $0 {start|stop|restart}"
exit 1
esac
[root@ctrl2 ~]#
