keepalived是由C语言编写的路由软件，是lvs的扩展项目，主要用作RealServer的健康状态检查以及LoadBalance主机和BackUP主机之间failover的实现。keepalived是一个类似于layer3, 4 & 7交换机制的软件，也就是我们平时说的第3层、第4层和第7层交换。本文主要介绍了其安装过程供大家参考。
1、获取安装软件
下载地址：http://www.keepalived.org/download.html
可以直接下载最新的版本1.2.13，也可以通过wget自动下载
# wget http://www.keepalived.org/software/keepalived-1.2.13.tar.gz
2、安装前提
a、确保ipvs已经被安装#如下，执行ipvsadm检查ipvs是否已经安装(当前大多数Linux缺省已安装)
[root@HKBO ~]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
#检查当前加载的内核模块，看是否存在ip_vs模块
[root@HKBO ~]# lsmod|grep ip_vs
ip_vs 122113 0
b、安装相应的依赖包
# yum -y install gcc gcc-c++ gcc-g77 ncurses-devel bison libaio-devel \
> cmake libnl* libpopt* popt-static openssl-devel
3、安装keepalived
[root@HKBO ~]# more /etc/issueCentOS release 5.9 (Final)# mkdir /usr/local/keepalived# cd /usr/local/src# wget http://www.keepalived.org/software/keepalived-1.2.13.tar.gz# tar -xvf keepalived-1.2.13.tar.gz # cd keepalived-1.2.13# ./configure --disable-fwmark --prefix=/usr/local/keepalived ...............Keepalived configuration------------------------Keepalived version : 1.2.13Compiler : gccCompiler flags : -g -O2 -DETHERTYPE_IPV6=0x86ddExtra Lib : -lssl -lcrypto -lcrypt Use IPVS Framework : YesIPVS sync daemon support : YesIPVS use libnl : Nofwmark socket support : NoUse VRRP Framework : YesUse VRRP VMAC : NoSNMP support : NoSHA1 support : NoUse Debug flags : No# make && make install# ls /usr/local/keepalived/ #查看安装完成后，生成了4个目录bin etc sbin share# cd /usr/local/keepalived/etc[root@HKBO etc]# tree.|-- keepalived| |-- keepalived.conf #keepalived的配置样例| `-- samples| |-- client.pem| |-- dh1024.pem| |-- keepalived.conf.HTTP_GET.port| |-- keepalived.conf.IPv6| |-- keepalived.conf.SMTP_CHECK| |-- keepalived.conf.SSL_GET| |-- keepalived.conf.fwmark| |-- keepalived.conf.inhibit| |-- keepalived.conf.misc_check| |-- keepalived.conf.misc_check_arg| |-- keepalived.conf.quorum| |-- keepalived.conf.sample| |-- keepalived.conf.status_code| |-- keepalived.conf.track_interface| |-- keepalived.conf.virtual_server_group| |-- keepalived.conf.virtualhost| |-- keepalived.conf.vrrp| |-- keepalived.conf.vrrp.localcheck| |-- keepalived.conf.vrrp.lvs_syncd| |-- keepalived.conf.vrrp.routes| |-- keepalived.conf.vrrp.scripts| |-- keepalived.conf.vrrp.static_ipaddress| |-- keepalived.conf.vrrp.sync| |-- root.pem| `-- sample.misccheck.smbcheck.sh|-- rc.d| `-- init.d| `-- keepalived`-- sysconfig `-- keepalived# cd /usr/local/keepalived/sbin# ./keepalived --help #获取keepalived的一些帮助Usage: ./keepalived [OPTION...] -f, --use-file=FILE Use the specified configuration file -P, --vrrp Only run with VRRP subsystem -C, --check Only run with Health-checker subsystem -l, --log-console Log messages to local console -D, --log-detail Detailed log messages -S, --log-facility=[0-7] Set syslog facility to LOG_LOCAL[0-7] -V, --dont-release-vrrp Don't remove VRRP VIPs and VROUTEs on daemon stop -I, --dont-release-ipvs Don't remove IPVS topology on daemon stop -R, --dont-respawn Don't respawn child processes -n, --dont-fork Don't fork the daemon process -d, --dump-conf Dump the configuration data -p, --pid=FILE Use specified pidfile for parent process -r, --vrrp_pid=FILE Use specified pidfile for VRRP child process -c, --checkers_pid=FILE Use specified pidfile for checkers child process -v, --version Display the version number -h, --help Display this help message# mkdir /etc/keepalived/# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ # cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/# ln -s /usr/local/keepalived/sbin/keepalived /sbin/# service keepalived restartStopping keepalived: [FAILED]Starting keepalived: [ OK ]# service keepalived statuskeepalived (pid 12092) is running...# chkconfig keepalived on# ip addr1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:50:56:84:04:2c brd ff:ff:ff:ff:ff:ff inet 192.168.1.66/24 brd 192.168.1.255 scope global eth0 inet 192.168.200.16/32 scope global eth0 inet 192.168.200.17/32 scope global eth0 inet 192.168.200.18/32 scope global eth0 inet6 fe80::250:56ff:fe84:42c/64 scope link valid_lft forever preferred_lft forever3: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0
4、有关keepalived.conf的配置项
[root@HKBO keepalived]# more keepalived.conf! Configuration File for keepalived#全局定义块，包含邮件定义部分，global_defs { notification_email { acassen@firewall.loc failover@firewall.loc sysadmin@firewall.loc } notification_email_from Alexandre.Cassen@firewall.loc smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id LVS_DEVEL //负载均衡器标识，在一个网络内，它应该是唯一的}#VRRP实例定义块，负责负载均衡器之间的失败切换vrrp_instance VI_1 { state MASTER //只有MASTER和BACKUP 2种状态，主为MASTER，从为BACKUP，使用大写 interface eth0 //监控的网络接口 virtual_router_id 51 //同一实例下virtual_router_id必须相同 priority 100 //定义优先级，数字越大，优先级越高 advert_int 1 //MASTER与BACKUP负载均衡器之间同步检查的时间间隔，单位是秒 authentication { //验证类型和密码 auth_type PASS auth_pass 1111 } virtual_ipaddress { //虚拟ip地址virtual_ipaddress,可以定义多个 192.168.200.16 192.168.200.17 192.168.200.18 }}#虚拟服务器定义块virtual_server 192.168.200.100 443 { //定义虚拟服务器 delay_loop 6 //delay_loop，健康检查时间间隔，单位是秒 lb_algo rr //负载调度算法，这里设置为rr，即轮询算法，互联网应用常使用wlc或rr lb_kind NAT //负载均衡转发规则。一般包括DR,NAT,TUN3种，在我的方案中，都使用DR的方式 nat_mask 255.255.255.0 //子网掩码 persistence_timeout 50 //会话保持时间，单位是秒（可以适当延长时间以保持session） protocol TCP //转发协议类型，有tcp和udp两种 real_server 192.168.201.100 443 { //真实服务器IP及端口 weight 1 //默认为1,0为失效 SSL_GET { url { path / digest ff20ad2481f97b1754ef3e12ecd3a9cc } url { path /mrtg/ digest 9b3a0c85a887a256d6939da88aabd8cd } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } }}virtual_server 10.10.10.2 1358 { delay_loop 6 lb_algo rr lb_kind NAT persistence_timeout 50 protocol TCP sorry_server 192.168.200.200 1358 real_server 192.168.200.2 1358 { weight 1 HTTP_GET { url { path /testurl/test.jsp digest 640205b7b0fc66c1ea91c463fac6334d } url { path /testurl2/test.jsp digest 640205b7b0fc66c1ea91c463fac6334d } url { path /testurl3/test.jsp digest 640205b7b0fc66c1ea91c463fac6334d } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.200.3 1358 { weight 1 HTTP_GET { url { path /testurl/test.jsp digest 640205b7b0fc66c1ea91c463fac6334c } url { path /testurl2/test.jsp digest 640205b7b0fc66c1ea91c463fac6334c } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } }}
5、配置主备keepalived
a、配置主备keepalived#主，以下主要列出keepalived.conf差异部分vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.220 192.168.1.230 }}#备，以下主要列出keepalived.conf差异部分vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.220 192.168.1.230 }}b、测试主备keepalived#启动主服务器上的keepalived服务[root@MASTER ~]# service keepalived startStarting keepalived: [ OK ][root@SZ-SYS-APP01 ~]# ip addr1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:50:56:84:1f:37 brd ff:ff:ff:ff:ff:ff inet 192.168.1.65/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.220/32 scope global eth0 #可以看到220和230的虚IP inet 192.168.1.230/32 scope global eth0 inet6 fe80::250:56ff:fe84:1f37/64 scope link valid_lft forever preferred_lft forever3: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0#启动备用服务器上的keepalived服务[root@BACKUP ~]# service keepalived startStarting keepalived: [ OK ]#下面的查询结果中，虚IP220和230并为出现在备用服务器[root@HKBO ~]# ip addr1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:50:56:84:04:2c brd ff:ff:ff:ff:ff:ff inet 192.168.1.66/24 brd 192.168.1.255 scope global eth0 inet6 fe80::250:56ff:fe84:42c/64 scope link valid_lft forever preferred_lft forever3: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0#关闭主服务上的keepalived服务，观察vip是否会漂移到备用服务 [root@MASTER ~]# service keepalived stopStopping keepalived: [ OK ][root@MASTER ~]# ip addr #关闭后，该命令可以看到220和230的虚IP已经不存在于主服务器1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:50:56:84:1f:37 brd ff:ff:ff:ff:ff:ff inet 192.168.1.65/24 brd 192.168.1.255 scope global eth0 inet6 fe80::250:56ff:fe84:1f37/64 scope link valid_lft forever preferred_lft forever3: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0#此时在备用服务器上查看到了漂移的vip地址[root@BACKUP ~]# ip addr1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:50:56:84:04:2c brd ff:ff:ff:ff:ff:ff inet 192.168.1.66/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.220/32 scope global eth0 inet 192.168.1.230/32 scope global eth0 inet6 fe80::250:56ff:fe84:42c/64 scope link valid_lft forever preferred_lft forever3: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0#如果再次启动主服务器上的keepalived服务，则会vip自动漂移到主服务器，不再验证。#Author : Leshami#Blog ：http://blog.csdn.net/leshami
6、配置双主keepalived
双主的keepalived方式实际上是互为主备，以避免单点故障#配置主备keepalivedMasterA: 192.168.1.65, VirtualIP: 192.168.1.220MasterB: 192.168.1.66, VirtualIP: 192.168.1.230#主，以下主要列出keepalived.conf差异部分vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.220 }}vrrp_instance VI_2 { state BACKUP interface eth0 virtual_router_id 52 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.230 }}#备，以下主要列出keepalived.conf差异部分vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.220 }}vrrp_instance VI_2 { state MASTER interface eth0 virtual_router_id 52 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.230 }}#从上面的配置文件中可以看出，实际上是增加了一个vrrp实例#验证过程略
7、编译时的错误No SO_MARK
#如果在编译时碰到了No SO_MARK错误，如下# ./configure checking for gcc... gccchecking whether the C compiler works... yeschecking for C compiler default output file name... a.outchecking for suffix of executables... checking whether we are cross compiling... nochecking for suffix of object files... o ...........checking for nl_socket_alloc in -lnl-3... nochecking for nl_socket_modify_cb in -lnl... noconfigure: WARNING: keepalived will be built without libnl support.checking for kernel version... 2.6.18checking for IPVS syncd support... yeschecking for kernel macvlan support... nochecking whether SO_MARK is declared... noconfigure: error: No SO_MARK declaration in headers#可以通过增加disable-fwmark参数来解决--disable-fwmark compile without SO_MARK support
