httpd is the Apache HyperText Transfer Protocol (HTTP) server program. It is designed to be run as a standalone daemon process. When used like this it will create a pool of child processes or threads to handle requests. Heartbeat is a daemon that provides cluster infrastructure (communication and membership) services to its clients. This allows clients to know about the presence (or disappearance!) of peer processes on other machines and to easily exchange messages with them.
Step 1: Pre-Configuration Requirements
Assign hostname httpd-primary to primary node with IP address 192.168.230.138 to eth0. Assign hostname httpd-slave to slave node with IP address 192.168.230.139 to eth0.
[root@httpd-primary ~]# cat /etc/hosts
127.0.0.1 localhost
192.168.230.138 httpd-primary
192.168.230.139 httpd-slave
Primary Server: httpd-primary
[root@httpd-primary ~]# uname -n
httpd-primary
Secondary Server: httpd-slave
[root@httpd-slave ~]# uname -n
httpd-slave
192.168.230.150 is the virtual IP address that will be used for our httpd webserver. Configure httpd on both server is ‘httpd-primary’ and ‘httpd-slave’
Now lets install Heartbeat on both servers.
Step 2: Install EPEL repo.
[root@httpd-primary ~]# wget \
http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
Change the ‘https’ to ‘http’ in ‘epel.repo’, if you get an error when you do a ‘yum install heartbeat’
[root@httpd-primary ~]# vim /etc/yum.repos.d/epel.repo
[root@httpd-primary ~]# yum install heartbeat
Step 3: Heartbeat configuration
[root@httpd-primary ~]# cp /usr/share/doc/heartbeat-3.0.4/authkeys /etc/ha.d/
[root@httpd-primary ~]# cp /usr/share/doc/heartbeat-3.0.4/ha.cf /etc/ha.d/
[root@httpd-primary ~]# cp /usr/share/doc/heartbeat-3.0.4/haresources /etc/ha.d/
Step 4:
[root@httpd-primary ~]# vi /etc/ha.d/authkeys
Then add the following lines:
auth 2
2 sha1 anyRandomKeyHere
Step 5: Change the permission of the authkeys file:
chmod 600 /etc/ha.d/authkeys
Step 6: Moving to our second file (ha.cf) which is the most important. So edit the ha.cf file with vi:
vi /etc/ha.d/ha.cf
Add the following lines in the ha.cf file:
logfile /var/log/ha-log
logfacility local0
keepalive 2
deadtime 30
initdead 120
bcast eth0
udpport 694
auto_failback on
node httpd-primary
node httpd-slave
Step 7: update haresources
vi /etc/ha.d/haresources
Add the following line:
httpd-primary 192.168.230.150 httpd
Step 8: Copy the /etc/ha.d/ directory from httpd-primary to httpd-slave:
scp -r /etc/ha.d/ root@httpd-slave:/etc/
Step 9: As we want httpd highly enabled let’s start configuring httpd:
vi /etc/httpd/conf/httpd.conf
Add this line in httpd.conf:
Listen 192.168.230.150:80
Step 10: Copy the /etc/httpd/conf/httpd.conf file from httpd-primary to httpd-slave:
scp /etc/httpd/conf/httpd.conf root@httpd-slave:/etc/httpd/conf/
Step 11: Create the file index.html on both nodes (httpd-primary & httpd-slave):
On httpd-primary:
echo "`uname -n` apache test server" > /var/www/html/index.html
On httpd-slave:
echo "`uname -n` apache test server" > /var/www/html/index.html
Step 11. Now start heartbeat on the primary httpd-primary and slave httpd-slave:
/etc/init.d/heartbeat start
Step 12. Open web-browser and type in the URL:
http://192.168.230.150
It will show 'httpd-primary apache test server'.
Step 13. Now stop the hearbeat daemon on httpd-primary:
/etc/init.d/heartbeat stop
In your browser type in the URL
http://192.168.230.150 and press enter.
It will show 'httpd-slave apache test server'.
We don’t need to create a virtual network interface and assign an IP address (192.168.230.150) to it. Heartbeat will do this for you, and start the service (httpd) itself. So don’t worry about this.
NOTE :
A. I had issues due to port access for testing disable ‘iptables’ if you face any issues. Here are the entries requires for iptables.
iptables -A OUTPUT -o lo -p udp -m udp -d 192.168.230.138 --dport 694 -j ACCEPT
iptables -A INPUT -i lo -p udp -m udp -d 192.168.230.138 --dport 694 -j ACCEPT
iptables -A OUTPUT -o eth0 -p udp -m udp -d 192.168.230.138 --dport 694 -j ACCEPT
iptables -A INPUT -i eth0 -p udp -m udp -d 192.168.230.138 --dport 694 -j ACCEPT
iptables -A OUTPUT -o lo -p udp -m udp -d 192.168.230.139 --dport 694 -j ACCEPT
iptables -A INPUT -i lo -p udp -m udp -d 192.168.230.139 --dport 694 -j ACCEPT
iptables -A OUTPUT -o eth0 -p udp -m udp -d 192.168.230.139 --dport 694 -j ACCEPT
iptables -A INPUT -i eth0 -p udp -m udp -d 192.168.230.139 --dport 694 -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp -m tcp -d 192.168.230.138 --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp -m tcp -d 192.168.230.138 --dport 80 -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp -m tcp -d 192.168.230.139 --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp -m tcp -d 192.168.230.139 --dport 80 -j ACCEPT
service iptables save
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