keepalived架设简单高可用的nginx的web服务器----那些你不知道的秘密

如果負載均衡軟件不使用LVS的話，那麼keepalived的配置是相當的簡單的，只需要配置好MASTER和SLAVE的vrrp相關配置就可以了，後端realServer的偵測就可以交給負載均衡軟件去做，比如我使用的負載均衡軟件是haproxy，個人認為比LVS更高效、更省資源、配置更簡單、條理更清晰。

下面來說說我在配置keepalived和nginx過程中遇到的一些問題，之所以會出現很多問題，關鍵就在於keepalived沒有配置文件查錯的機制，不管你的配置文件寫成了啥樣，你照樣可以成功啟動keepalived，它不會給你任務錯誤提示，就像它沒有出錯一樣，你查看進程時也不會覺得它異常，和普通的正常的進程一模一樣，因此一旦配置文件配置錯誤就很要命了。

test2 eth2:192.168.46.132192.168.46.132test3 eth2:192.168.46.133192.168.46.133

如果你使用LVS作為負載均衡器的話，需要讓編譯程序能找到你的linux內核所在目錄，要帶 --with-kernel-dir=/usr/src/linux參數編譯，因此你需要先安裝內核開發包：with-kernel-dir=/usr/src/linux參數編譯，因此你需要先安裝內核開發包：yum install kernel-devel這是CENTOS的安裝方法。接著為內核源文件目錄做一個軟鏈接：ln -s /usr/src/kernels/`uname -r` /usr/src/linux現在可以開始編譯了：./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/linuxwith-kernel-dir=/usr/src/linux如果不使用LVS，就不需要帶--with-kernel-dir參數，我用的是nginx，因此沒有指定此參數。with-kernel-dir參數，我用的是nginx，因此沒有指定此參數。configure結束，開始make時，出现了以下錯誤：/usr/include/stdint.h:41: error: conflicting types for‘int64_t’include/stdint.h:41: error: conflicting types forinclude/stdint.h:41: error: conflicting types for‘int64_t’/usr/src/linux/include/linux/types.h:126: error: previous declaration of ‘int64_t’ was hereinclude/linux/types.h:126: error: previous declaration of ‘int64_t’ was here/usr/include/stdint.h:56: error: conflicting types for‘uint64_t’include/stdint.h:56: error: conflicting types forinclude/stdint.h:56: error: conflicting types for‘uint64_t’/usr/src/linux/include/linux/types.h:124: error: previous declaration of ‘uint64_t’ was hereinclude/linux/types.h:124: error: previous declaration of ‘uint64_t’ was hereIn file included from /usr/include/stdlib.h:438,include/stdlib.h:438,在源目錄裡找到keepalived/libipvs-2.6/ip_vs.h文件，編輯它，把 #include
     
       移动到 #include
      
        的下面即可，再次make正常，make install安裝完畢。2.6/ip_vs.h文件，編輯它，把 #include
       
         移动到 #include2.6/ip_vs.h文件，編輯它，把 #include
        
          移动到 #include
         
           的下面即可，再次make正常，make install安裝完畢。
         
        
       
      
     

/etc/keepalived/keepalived.confglobal_defs {notification_email {root@localhost}notification_email_from root@localhostsmtp_server 127.0.0.1127.0.0.1smtp_connect_timeout 30router_id LVS_DEVEL}vrrp_script chk_http_port {script "/root/nginx_pid.sh"interval 2weight 2}vrrp_instance VI_1 {state MASTERinterfaceeth2virtual_router_id 51mcast_src_ip 192.168.46.132192.168.46.132priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.46.200/24}track_script {chk_http_port}}

[root@test3 init.d]# vim /etc/keepalived/keepalived.conf!Configuration File forkeepalivedforkeepalivedglobal_defs {notification_email {root@localhost}notification_email_from root@localhostsmtp_server 127.0.0.1127.0.0.1smtp_connect_timeout 30router_id LVS_DEVEL}vrrp_script chk_http_port {script "/root/nginx_pid.sh"interval 2weight 2}vrrp_instance VI_1 {state BACKUPinterfaceeth2virtual_router_id 51mcast_src_ip 192.168.46.133192.168.46.133priority 99advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.46.200/24}track_script {chk_http_port}}~

[root@test2 init.d]# vim /root/nginx_pid.sh#!/bin/bashA=`ps -C nginx --no-header |wc -l`if[ $A -eq 0];then[ $A -eq 0if[ $A -eq 0];thenkill -HUP `cat /usr/local/nginx/logs/nginx.pid`sleep 3if[ `ps -C nginx --no-header |wc -l` -eq 0];then[ `ps -C nginx --no-header |wc -l` -eq 0if[ `ps -C nginx --no-header |wc -l` -eq 0];thenkillall keepalivedfifi