====== LoadBalancing avec KeepAlived LVS ======
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===== Server Applicatifs ( Apache / FTP ) =====

==== Configuration kernel nécessaire pour le mode de loadbalancing des serveurs LVS ====


  # vi /etc/sysctl.conf

  # Useful for LVS loadbalancing on the same network
  net.ipv4.conf.all.arp_ignore=1
  net.ipv4.conf.all.arp_announce=2
  net.ipv4.conf.eth0.arp_ignore=1
  net.ipv4.conf.eth0.arp_announce=2

==== Configuration d'un tunnel IPIP pour la VIP (géré par les serveurs LVS) ====

* Debian

  # vi /etc/network/interfaces
  
  auto tunl0
  iface tunl0 inet static
      address 192.168.1.99 (<<< nouvelle vip créée)
      netmask 255.255.255.255
      broascast 192.168.1.255

  # ifup tunl0

* Red-Hat

  # vi /etc/sysconfig/network-scripts/ifcfg-tunl0
  
  DEVICE=tunl0
  IPADDR=192.168.1.99
  NETMASK=255.255.255.255
  BROADCAST=192.168.1.255
  ONBOOT=yes
  TYPE=IPIP

  # ifup tunl0

  # ifconfig tunl0
  tunl0 Link encap:IPIP Tunnel HWaddr 
  inet addr:192.168.1.99 Mask:255.255.255.255
  UP RUNNING NOARP MTU:1480 Metric:1
  RX packets:273 errors:0 dropped:0 overruns:0 frame:0
  TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
  collisions:0 txqueuelen:0 
  RX bytes:11328 (11.0 KiB) TX bytes:0 (0.0 b)

===== Serveur: LVS =====

==== Configuration kernel ====

  # vi /etc/sysctl.conf
  
  # for LVS tun
  net.ipv4.ip_forward=1

==== Packages Nécessaire ====

  # apt-get install keepalived

==== Configuration de la VIP VLZ ====

Ceci et le fichier de configuration du serveur LVS_1 (server MASTER) le serveur LVS_2 à le même fichier de configuration hormis "state MASTER" à changer par "state BACKUP"

  # cat /etc/keepalived/keepalived.conf

  ! Configuration File for keepalived
  
  global_defs {
   notification_email {
   postmaster@your-domain
   }
   notification_email_from postmaster@your-domain
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_XXX
  }
  
  vrrp_sync_group VG1 {
   group {
   VI_1
   }
  }
  
  vrrp_instance VI_1 {
   state MASTER
   interface eth0
   garp_master_delay 10
   smtp_alert
   virtual_router_id 51
   priority 100
   advert_int 1
   authentication {
   auth_type PASS
   auth_pass 1111
   }
   virtual_ipaddress {
   192.168.1.99
   }
  }
  
  virtual_server 192.168.1.99 80 {
   delay_loop 6
   lb_algo rr
   lb_kind TUN
   persistence_timeout 600
   protocol TCP
  
   real_server 192.168.1.2 80 {
   weight 100
   TCP_CHECK {
   connect_port 80
   connect_timeout 3
   }
   }
   real_server 192.168.1.3 80 {
   weight 100
   TCP_CHECK {
   connect_port 80
   connect_timeout 3
   }
   }
  }

===== Commandes utile pour voir l'état des VIP =====

  # ipvsadm -l
  IP Virtual Server version 1.2.1 (size=4096)
  Prot LocalAddress:Port Scheduler Flags
   -> RemoteAddress:Port Forward Weight ActiveConn InActConn
  TCP 192.168.1.99:www rr persistent 600
   -> 192.168.1.2:www Tunnel 100 0 0
   -> 192.168.1.3:www Tunnel 100 0 0

  # ipvsadm -Ln --stats
  IP Virtual Server version 1.2.1 (size=4096)
  Prot LocalAddress:Port               Conns   InPkts  OutPkts  InBytes OutBytes
    -> RemoteAddress:Port
  TCP  192.168.1.99:80                     0        0        0        0        0
    -> 192.168.1.2:80                      0        0        0        0        0
    -> 192.168.1.3:80                      0        0        0        0        0