Load balanced High-Availability Apache Cluster

 Load balancers takes care of the load on a web server nodes and tried to direct request to the node with least amount on load  Many web applications make use of sessions, and if you are in a session on Apache node 1, you would lose that session if suddenly node 2 served your requests.  If an Apache nodes goes down, the load balancer realizes that and directs all incoming requests to the remaining node. Advantage Of Load Balancing

 Four nodes( two apache nodes and two load balancer nodes)  Five IP Addresses  One for each node  One for virtual IP address that will be shared by the load balancer. Requirements For Setup

 Apache node 1: webserver1.radford.edu (webserver1) - IP address: ; Apache document root: /var/www  Apache node 2: webserver2.radford.edu (webserver2) - IP address: ; Apache document root: /var/www  Load Balancer node 1: loadb1.radford.edu (loadb1) - IP address:  Load Balancer node 2: loadb2.radford.edu (loadb2) - IP address:  Virtual IP Address: (used for incoming requests) IP Address Schema

 Loadb1 / Loadb2  echo ip_vs_dh >> /etc/modules echo ip_vs_ftp >> /etc/modules echo ip_vs >> /etc/modules echo ip_vs_lblc >> /etc/modules echo ip_vs_lblcr >> /etc/modules echo ip_vs_lc >> /etc/modules echo ip_vs_nq >> /etc/modules echo ip_vs_rr >> /etc/modules echo ip_vs_sed >> /etc/modules echo ip_vs_sh >> /etc/modules echo ip_vs_wlc >> /etc/modules echo ip_vs_wrr >> /etc/modules Enable IPVS On The Load Balancers

 modprobe ip_vs_dh modprobe ip_vs_ftp modprobe ip_vs modprobe ip_vs_lblc modprobe ip_vs_lblcr modprobe ip_vs_lc modprobe ip_vs_nq modprobe ip_vs_rr modprobe ip_vs_sed modprobe ip_vs_sh modprobe ip_vs_wlc modprobe ip_vs_wrr

 vi /etc/apt/sources.list  Lines must be added  deb sarge main  deb-src sarge main  apt-get update  apt-get install ultramonkey Install Ultra Monkey On The Load Balancers

 Do you want to automatically load IPVS rules on boot? <-- No  Select a daemon method. <-- none UltraMonkey Setup

 vi /etc/sysctl.conf  Add the following lines to sysct1.conf file  Net.ipv4.ip_forward = 1  sysctl -p Enable Packet Forwarding On Load Balancers

 vi /etc/ha.d/ha.cf  Add to config file  logfacility local0  bcast eth0 # Linux  mcast eth  auto_failback off  node loadb1  node loadb2  respawn hacluster /usr/lib/heartbeat/ipfail  apiauth ipfail gid=haclient uid=hacluster Configure heartbeat And Idirectord

 uname -n  vi /etc/ha.d/haresources  loadb1 \  ldirectord::ldirectord.cf \  LVSSyncDaemonSwap::master \  IPaddr2:: /24/eth0/

 uname –n  vi /etc/ha.d/authkeys  auth 3  3 md5 somerandomstring  chmod 600 /etc/ha.d/authkeys

 vi /etc/ha.d/ldirectord.cf  checktimeout=10 checkinterval=2 autoreload=no logfile="local0" quiescent=yes virtual= :80 real= :80 gate real= :80 gate fallback= :80 gate service=http request="ldirector.html" receive="Test Page" scheduler=rr protocol=tcp checktype=negotiate

 update-rc.d heartbeat start stop  update-rc.d -f ldirectord remove  /etc/init.d/ldirectord stop  /etc/init.d/heartbeat start