Http://linux.chinaunix.net/techdoc/net/2009/07/21/1125256.shtml
# Modprobe ip_vs
| LVS + keepalived for high-availability clusters |
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| Source: chinaunix blog Date: 2009.07.21 (comments in total) I want to comment |
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Operating System Platform: centos5.2
Software: LVS + keepalived
LVS + keepalived Introduction
LVS
LVS is short for Linux virtual server, which is a virtual server cluster system. This project was established by Dr. Zhang Wenyu in May 1998 and is one of the earliest free software projects in China. Currently, three IP Server Load balancer technologies are available (Vs/NAT, VS/TUN, and VS/DR );
Ten scheduling algorithms (RRR | WRR | LC | wlc | lblc | lblcr | DH | sh | sed | NQ ).
Keepalvied
Keepalived is mainly used for RealServer health check and Failover implementation between loadbalance host and backup host.
IP configuration information:
- LVS-DR-master 192.168.20.6
- LVS-DR-BACKUP 192.168.20.7
- LVS-DR-VIP 192.168.2.170
- WEB1-Realserver 192.168.2.171
- WEB2-Realserver 192.168.2.172
- Gateway 192.168.2.253
Install the LVS and keepalvied packages
1. Download related software packages
# Mkdir/usr/local/src/LVS
# Cd/usr/local/src/LVS
# Wget
Http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz
# Wget
Http://www.keepalived.org/software/keepalived-1.1.15.tar.gz
2. Install LVS and keepalived
- # Lsmod | grep ip_vs
- # Uname-R
- 2.6.18-53. el5pae
- # Ln-S/usr/src/kernels/2.6.18-53. el5PAE-i686 // usr/src/Linux
- # Tar zxvf ipvsadm-1.24.tar.gz
- # Cd ipvsadm-1.24
- # Make & make install
- # Find/-name ipvsadm # view the location of ipvsadm
- # Tar zxvf keepalived-1.1.15.tar.gz
- # Cd keepalived-1.1.15
- #./Configure & make install
- # Find/-name keepalived # view the location of keepalived
- # Cp/usr/local/etc/rc. d/init. d/keepalived/etc/rc. d/init. d/
- # Cp/usr/local/etc/sysconfig/keepalived/etc/sysconfig/
- # Mkdir/etc/keepalived
- # Cp/usr/local/etc/keepalived. CONF/etc/keepalived/
- # Cp/usr/local/sbin/keepalived/usr/sbin/
- # Service keepalived START | stop # Make the system startup service easy to manage.
4. Configure LVS for Load Balancing
1. LVS-DR, configure LVS script for Load Balancing
VI/usr/local/sbin/lvs-dr.sh
#! /Bin/bash
# Description: Start LVS of directorserver
# Written by: netseek
Http://www.linuxtone.org
GW = 192.168.2.253
# Website Director VIP.
Web_vip = 192.168.2.170
Web_rip1 = 192.168.2.171
Web_rip2 = 192.168.2.172
./Etc/rc. d/init. d/functions
Logger $0 called with $1
Case "$1" in
Start)
# Clear all iptables rules.
/Sbin/iptables-F
# Reset iptables counters.
/Sbin/iptables-z
# Clear all rules SADM rules/services.
/Sbin/ipvsadm-C
# Set lvs vip for Dr
/Sbin/ipvsadm -- set 30 5 60
/Sbin/ifconfig eth0: 0 $ web_vip broadcast $ web_vip netmask 255.255.255 up
/Sbin/route add-host $ web_vip Dev eth0: 0
/Sbin/ipvsadm-a-t $ web_vip: 80-s WRR-P 3
/Sbin/ipvsadm-a-t $ web_vip: 80-r $ web_rip1: 80-g-W 1
/Sbin/ipvsadm-a-t $ web_vip: 80-r $ web_rip2: 80-g-W 1
Touch/var/lock/subsys/ipvsadm>/dev/null 2> & 1
# Set ARP
/Sbin/arping-I eth0-C 5-S $ web_vip $ Gw>/dev/null 2> & 1
;;
Stop)
/Sbin/ipvsadm-C
/Sbin/ipvsadm-z
Ifconfig eth0: 0 down
Route del $ web_vip>/dev/null 2> & 1
Rm-RF/var/lock/subsys/ipvsadm>/dev/null 2> & 1
/Sbin/arping-I eth0-C 5-S $ web_vip $ GW
Echo "ipvsadm stoped"
;;
Status)
If [! -E/var/lock/subsys/ipvsadm]; then
Echo "ipvsadm is stoped"
Exit 1
Else
Ipvsadm-ln
Echo "...... wait SADM is OK ."
Fi
;;
*)
Echo "Usage: $0 {START | stop | status }"
Exit 1
Esac
Exit 0
2. Configure the RealServer script.
#! /Bin/bash
# Written by netseek
# Description: config RealServer Lo and apply noarp
Web_vip = 192.168.2.170
./Etc/rc. d/init. d/functions
Case "$1" in
Start)
Ifconfig lo: 0 $ web_vip netmask 255.255.255.255 broadcast $ web_vip
/Sbin/route add-host $ web_vip Dev lo: 0
Echo "1">/proc/sys/NET/IPv4/CONF/LO/arp_ignore
Echo "2">/proc/sys/NET/IPv4/CONF/LO/arp_announce
Echo "1">/proc/sys/NET/IPv4/CONF/All/arp_ignore
Echo "2">/proc/sys/NET/IPv4/CONF/All/arp_announce
Sysctl-P>/dev/null 2> & 1
Echo "RealServer start OK"
;;
Stop)
Ifconfig lo: 0 down
Route del $ web_vip>/dev/null 2> & 1
Echo "0">/proc/sys/NET/IPv4/CONF/LO/arp_ignore
Echo "0">/proc/sys/NET/IPv4/CONF/LO/arp_announce
Echo "0">/proc/sys/NET/IPv4/CONF/All/arp_ignore
Echo "0">/proc/sys/NET/IPv4/CONF/All/arp_announce
Echo "RealServer stoped"
;;
Status)
# Status of LVS-DR Real Server.
Islothere = '/sbin/ifconfig lo: 0 | grep $ web_vip'
Isrothere = 'netstat-Rn | grep "Lo: 0" | grep $ web_vip'
If [! "$ Islothere"-o! "Isrothere"]; then
# Either the route or the Lo: 0 device
# Not found.
Echo "LVS-DR Real Server stopped ."
Else
Echo "LVS-DR running ."
Fi
;;
*)
# Invalid entry.
Echo "$0: Usage: $0 {START | status | stop }"
Exit 1
;;
Esac
Exit 0
Attach/etc/sysctl. conf on the RealServer:
# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl (8) and
# Sysctl. conf (5) for more details.
# Controls IP packet forwarding
Net. ipv4.ip _ forward = 1
# Controls source route verification
Net. ipv4.conf. Default. rp_filter = 1
# Do not accept Source Routing
Net. ipv4.conf. Default. accept_source_route = 0
# Controls the system request debugging functionality of the kernel
Kernel. sysrq = 0
# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
Kernel. core_uses_pid = 1
Net. ipv4.conf. Lo. arp_ignore = 1
Net. ipv4.conf. Lo. arp_announce = 2
Net. ipv4.conf. All. arp_ignore = 1
Net. ipv4.conf. All. arp_announce = 2
Or use secondary IP address.
# Vi/etc/sysctl. conf
Add the following content as shown above:
Net. ipv4.conf. Lo. arp_ignore = 1
Net. ipv4.conf. Lo. arp_announce = 2
Net. ipv4.conf. All. arp_ignore = 1
Net. ipv4.conf. All. arp_announce = 2
# Sysctl-P
# Ip addr add 61.164.122.8/32 Dev Lo
# IP add list to check whether it is bound
3. Start the LVS-Dr script and the RealServer startup. On the DR, you can view the current LVS status:
# Watch ipvsadm-ln
5. Use keepalvied to achieve load balancing and high availability
1. Configure keepalived. conf on the master server Load balancer.
# Vi/etc/keepalived. conf (Master Scheduler)
! Configuration file for keepalived
Global_defs {
Notification_email {
[Email protected]
[Email protected]
[Email protected]
}
Notification_email_from
[Email protected]
Smtp_server 127.0.0.1
Smtp_connect_timeout 30
Router_id lvs_devel
}
Vrrp_instance vi_1 {
State master
Interface eth0
Virtual_router_id 51
Priority100
Advert_int 1
Authentication {
Auth_type pass
Auth_pass 1111
}
Virtual_ipaddress {
192.168.2.170
}
}
Virtual_server 192.168.2.170 80 {
Delay_loop 6
Lb_algo WRR
Lb_kind Dr
Persistence_timeout 60
Protocol TCP
Real_server 192.168.2.171 80 {
Weight 3
Tcp_check {
Connect_timeout 10
Nb_get_retry 3
Delay_before_retry 3
Connect_port 80
}
}
Real_server 192.168.2.172 80 {
Weight 3
Tcp_check {
Connect_timeout 10
Nb_get_retry 3
Delay_before_retry 3
Connect_port 80
}
}
}
On the slave Scheduler:
# Vi/etc/keepalived. conf (Backup Scheduler)
! Configuration file for keepalived
Global_defs {
Notification_email {
[Email protected]
[Email protected]
[Email protected]
}
Notification_email_from
[Email protected]
Smtp_server 127.0.0.1
Smtp_connect_timeout 30
Router_id lvs_devel
}
Vrrp_instance vi_1 {
State backup
Interface eth0
Virtual_router_id 51
Priority 99
Advert_int 1
Authentication {
Auth_type pass
Auth_pass 1111
}
Virtual_ipaddress {
192.168.2.170
}
}
Virtual_server 192.168.2.170 80 {
Delay_loop 6
Lb_algo WRR
Lb_kind Dr
Persistence_timeout 60
Protocol TCP
Real_server 192.168.2.171 80 {
Weight 3
Tcp_check {
Connect_timeout 10
Nb_get_retry 3
Delay_before_retry 3
Connect_port 80
}
}
Real_server 192.168.2.172 80 {
Weight 3
Tcp_check {
Connect_timeout 10
Nb_get_retry 3
Delay_before_retry 3
Connect_port 80
}
}
}
2. Configure the backup server as above. Install LVS and then install keepalived. Then, configure/etc/keepalived. conf. You only need to change the red part.
3. VI/etc/rc. Local
#/Usr/local/sbin/lvs-dr.sh to annotate the lvs-dr.sh script.
#/Usr/local/sbin/lvs-dr.sh Stop LVS-Dr script
#/Etc/init. d/keepalived start the keepalived service, and keepalived can be configured with keepalived. conf.
Set files to achieve load balancing and high availability.
4. Check whether the LVS service is normal.
# Watch ipvsadm-ln
IP Virtual Server version 1.2.1 (size = 4096)
Prot localaddressort sched1_flags
-> Remoteaddressort forward weight activeconn inactconn
TCP 61.164.122.8: 80 WRR persistent 60
-> 61.164.122.10: 80 Route 3 0 0
-> 61.164.122.9: 80 Route 3 0 0
Copy code
# Tail-F/var/log/message: Listen to logs, check the status, and test whether LVS Server Load balancer and high availability are valid.
5. Stop the keepalived Service of the master server and check whether the bakcup server can take over the service normally.
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