HAProxy &Keepalived

HAProxy &Keepalived

       For configuring HA-Load balancer, You need 2 virtual/physical servers for the load-balancers and 2 virtual/physical servers to load-balance. In addition to the 4 IP addresses needed by the servers themselves, a fifth virtual IP address (VIP) is necessary. The two load-balancers and the VIP need to be in the same network segment.

HAProxy and keepalived. So, HAProxy will be used as load-balancing software, keepalived as high availability solution and apache as software to load-balance.

Load Balancer 1: haproxy1.psi.com, IP address: 192.168.0.25

Load Balancer 2: haproxy2.psi.com, IP address: 192.168.0.26

MGMT Server 1: mgmt1.psi.com, IP address: 192.168.0.21

MGMT Server 2: mgmt1.psi.com, IP address: 192.168.0.22

We also need a virtual IP address that floats between lb1 and lb2: 192.168.0.31

Here's a little diagram that shows our setup:

    shared IP=192.168.0.31
   192.168.0.25     192.168.0.26        192.168.0.21            192.168.0.22
 -------+--------- ---+--------------+-----------+-----------------+--------- ---+--------------+
    |                          |                      |       |                       |             |                        |
     +--+--+ +--+--+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+--
     | lb1 |                    | lb2 |                 |  http1  |                           |  http2  |
     +-----++-----+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+
     haproxy              haproxy                                  2 MGMT servers (Apache)
     keepalived        keepalived

HAProxy Configuration on server 1

HaProxy configuration-

   #Yum install haproxy

Copy the below configuration file below defaults and change the portnumber,name of the server& server ip by requirements

vi /etc/haproxy/haproxy.conf

listen cloudstack_ui_443(Port https-443,Http-8080)

bind *:443

mode http     

 balance source

server mgmt1.psi.com 192.168.0.21:443 cookie A check(Server name&IP address)

server mgmt2.psi.com 192.168.0.22:443 cookie B check(Server name&IP address)

      listen cloudstack_systemvm_8250(System VM-Mgmt server port port)

            bind *:8250

            mode tcp

            balance source

server mgmt1.psi.com 192.168.0.21:8250 maxconn 32 check (Servername&IP address)

server mgmt2.psi.com 192.168.0.22:8250 maxconn 32 check (Servername&IP address) 

Keepalived configuration on server 1(used for virtual ip creation)

        #Yum install keepalived

•         cp /etc/keepalived/keepalived.conf  /etc/keepalived/keepalived.conf.orig(Copy original file and keep it as a backup)

•         Open vi editor and copy below content in to configuration file(192.168.0.31 virtual ip)

vi /etc/keepalived/keepalived.conf

  vrrp_script chk_haproxy {

    script "killall -0 haproxy" # check the haproxy process

    interval 2 # every 2 seconds

    weight 2 # add 2 points if OK

 }

 vrrp_instance VI_1 {

     interface eth0 # interface to monitor

     state MASTER # MASTER on haproxy1, BACKUP on haproxy2

     virtual_router_id 77 

     priority 200 # 101 on haproxy1, 100 on haproxy2 

  virtual_ipaddress {     

    192.168.0.31 #dev eth0 # virtual ip address 

  }  

  track_script   {

      chk_haproxy 

  }

} 

HAProxy Configuration on server 2

HaProxy configuration-

   #Yum install haproxy

Copy the below configuration file below defaults and change the portnumber,name of the server& server ip by requirements

vi /etc/haproxy/haproxy.conf

listen cloudstack_ui_443(Port https-443,Http-8080)

bind *:443

mode http     

 balance source

server mgmt1.psi.com 192.168.0.21:443 cookie A check(Server name&IP address)

server mgmt2.psi.com 192.168.0.22:443 cookie B check(Server name&IP address)

      listen cloudstack_systemvm_8250(System VM-Mgmt server port port)

            bind *:8250

            mode tcp

            balance source

server mgmt1.psi.com 192.168.0.21:8250 maxconn 32 check (Servername&IP address)

server mgmt2.psi.com 192.168.0.22:8250 maxconn 32 check (Servername&IP address)

To check keep alive status: ip addr | grep eth0

Keepalived configuration on server 2(used for virtual ip creation)

        #Yum install keepalived

•         cp /etc/keepalived/keepalived.conf  /etc/keepalived/keepalived.conf.orig(Copy original file and keep it as a backup)

•         Open vi editor and copy below content in to configuration file(192.168.0.31 virtual ip)

vi /etc/keepalived/keepalived.conf

  vrrp_script chk_haproxy {

    script "killall -0 haproxy" # check the haproxy process

    interval 2 # every 2 seconds

    weight 2 # add 2 points if OK

 }

 vrrp_instance VI_1 {

     interface eth0 # interface to monitor

    state MASTER # MASTER on haproxy1, BACKUP on haproxy2

     virtual_router_id 77 

     priority 111 # 101 on haproxy1, 100 on haproxy2 

  virtual_ipaddress {     

    192.168.0.31 #dev eth0 # virtual ip address 

  }  

  track_script   {

      chk_haproxy 

  }

}

 To check keep alive status: ip addr | grep eth0