一、 环境描述
Linux server A (CentOS release 5.8 Final) 实IP:192.168.4.97 虚IP：192.168.4.96
Linux server B (CentOS release 5.8 Final) 实IP:192.168.4.99 虚IP：192.168.4.98
域名环境（DNS轮询解析到虚IP）：
server.osapub.com 192.168.4.96
server.osapub.com 192.168.4.98
二、 简单架构示意图
描述：前端两台NGINX做DNS轮询，通过虚IP漂移+HA监控脚本相结合，实现前端两台NGINX高可用，利用NGINX反向代理功能对后端varnish实现高可用集群。
三、软件环境搭建
3.1 编译安装nginx
?
#!/bin/bash
####nginx 环境安装脚本，注意环境不同可能导致脚本运行出错，如果环境不同建议手工一条一条执行指令。
#创建工作目录
mkdir -p /dist/{dist,src}
cd /dist/dist
#下载安装包
wget http://bbs.osapub.com/down/google-perftools-1.8.3.tar.gz &> /dev/null
wget http://bbs.osapub.com/down/libunwind-0.99.tar.gz &> /dev/null
wget http://bbs.osapub.com/down/pcre-8.01.tar.gz &> /dev/null
wget http://bbs.osapub.com/down/nginx-1.0.5.tar.gz &> /dev/null
#------------------------------------------------------------------------
# 使用Google的开源TCMalloc库，忧化性能
cd /dist/src
tar zxf ../dist/libunwind-0.99.tar.gz
cd libunwind-0.99/
## 注意这里不能加其它 CFLAGS加速编译参数
CFLAGS=-fPIC ./configure
make clean
make CFLAGS=-fPIC
make CFLAGS=-fPIC install
if [ "$?" == "0" ]; then
echo "libunwind-0.99安装成功." >> ./install_log.txt
else
echo "libunwind-0.99安装失败." >> ./install_log.txt
exit 1
fi
##----------------------------------------------------------
## 使用Google的开源TCMalloc库，提高MySQL在高并发情况下的性能
cd /dist/src
tar zxf ../dist/google-perftools-1.8.3.tar.gz
cd google-perftools-1.8.3/
CHOST="x86_64-pc-linux-gnu" CFLAGS="-march=nocona -O2 -pipe" CXXFLAGS="-march=nocona -O2 -pipe" \
./configure
make clean
make && make install
if [ "$?" == "0" ]; then
echo "google-perftools-1.8.3安装成功." >> ./install_log.txt
else
echo "google-perftools-1.8.3安装失败." >> ./install_log.txt
exit 1
fi
echo "/usr/local/lib" > /etc/ld.so.conf.d/usr_local_lib.conf
/sbin/ldconfig
################ 安装nginx ##########################
#安装Nginx所需的pcre库
cd /dist/src
tar zxvf ../dist/pcre-8.01.tar.gz
cd pcre-8.01/
CHOST="x86_64-pc-linux-gnu" CFLAGS="-march=nocona -O2 -pipe" CXXFLAGS="-march=nocona -O2 -pipe" \
./configure
make && make install
if [ "$?" == "0" ]; then
echo "pcre-8.01安装成功." >> ./install_log.txt
else
echo "pcre-8.01安装失败." >> ./install_log.txt
exit 1
fi
cd ../
## 安装Nginx
## 为优化性能，可以安装 google 的 tcmalloc ，之前己经安装过了
## 所以我们编译 Nginx 时，加上参数 --with-google_perftools_module
## 然后在启动nginx前需要设置环境变量 export LD_PRELOAD=/usr/local/lib/libtcmalloc.so
## 加上 -O2 参数也能优化一些性能
##
## 默认的Nginx编译选项里居然是用 debug模式的(-g参数)，在 auto/cc/gcc 文件最底下，去掉那个 -g 参数
## 就是将 CFLAGS="$CFLAGS -g" 修改为 CFLAGS="$CFLAGS" 或者直接删除这一行
cd /dist/src
rm -rf nginx-1.0.5
tar zxf ../dist/nginx-1.0.5.tar.gz
cd nginx-1.0.5/
sed -i 's#CFLAGS="$CFLAGS -g"#CFLAGS="$CFLAGS "#' auto/cc/gcc
make clean
CHOST="x86_64-pc-linux-gnu" CFLAGS="-march=nocona -O2 -pipe" CXXFLAGS="-march=nocona -O2 -pipe" \
./configure --user=www --group=www \
--prefix=/usr/local/nginx \
--with-http_stub_status_module \
--with-google_perftools_module
make && make install
if [ "$?" == "0" ]; then
echo "nginx-1.0.5安装成功." >> ./install_log.txt
else
echo "nginx-1.0.5安装失败." >> ./install_log.txt
exit 1
fi
cd ../
#创建Nginx日志目录
mkdir -p /data/logs
chmod +w /data/logs
chown -R www:www /data/logs
cd /usr/local/nginx/
mv conf conf_bak
ln -s /data/conf/nginx/ conf
echo 'export LD_PRELOAD=/usr/local/lib/libtcmalloc.so' > /root/nginx_start
echo 'ulimit -SHn 51200' >> /root/nginx_start
echo '/usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf' >> /root/nginx_start
echo '/usr/local/nginx/sbin/nginx -t' > /root/nginx_reload
echo 'kill -HUP `cat /usr/local/nginx/logs/nginx.pid`' >> /root/nginx_reload
chmod 700 /root/nginx_*3.2 编译安装varnish
#!/bin/bash
#进入工作目录
cd /dist/dist
#下载安装包
wget <a href="\"http://bbs.osapub.com/down/varnish-3.0.0.tar.gz\"" target="\"_blank\"">http://bbs.osapub.com/down/varnish-3.0.0.tar.gz</a> &> /dev/null
cd /dist/src
rm -fr varnish-3.0.0
export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
tar zxvf ../dist/varnish-3.0.0.tar.gz
cd varnish-3.0.0
#编译参数可以根据自己需要定制
./configure -prefix=/usr/local/varnish -enable-debugging-symbols -enable-developer-warnings -enable-dependency-tracking
make && make install
if [ "$?" == "0" ]; then
echo "varnish-3.0.0安装成功." >> ./install_log.txt
else
echo "varnish-3.0.0安装失败." >> ./install_log.txt
exit 1
fi
#设置启动、重启脚本
cat > /root/varnish_restart.sh <<EOF
#!/bin/bash
pkill varnish
pkill varnish
ulimit -SHn 51200
/usr/local/varnish/sbin/varnishd -n /data/varnish -f /usr/local/varnish/vcl.conf -a 0.0.0.0:81 -s malloc,12G -g www -u www -w 4000,12000,10 -T 127.0.0.1:3500 -p http_max_hdr=256 -p http_req_hdr_len=8192
EOF
cat > /root/varnish_start.sh <<EOF
#!/bin/bash
ulimit -SHn 51200
/usr/local/varnish/sbin/varnishd -n /data/varnish -f /usr/local/varnish/vcl.conf -a 0.0.0.0:81 -s malloc,12G -g www -u www -w 4000,12000,10 -T 127.0.0.1:3500 -p http_max_hdr=256 -p http_req_hdr_len=8192
EOF
chmod 755 /root/varnish*三、 配置varnish一些参数说明：
Backend servers
Varnish有后端（或称为源）服务器的概念。后端服务器是指Varnish提供加速服务的那台，通常提供内容。
第一件要做的事情是告诉Varnish，哪里能找到要加速的内容。
vcl_recv
vcl_recv是在请求开始时调用的。完成该子程序后，请求就被接收并解析了。用于确定是否需要服务请求，怎么服务，如果可用，使用哪个后端。
在vcl_recv中，你也可以修改请求。通常你可以修改cookie，或添加/移除请求头信息。
注意在vcl_recv中，只可以使用请求对象req。
vcl_fetch
vcl_fetch是在文档从后端被成功接收后调用的。通常用于调整响应头信息，触发ESI处理，万一请求失败就换个后端服务器。
在vcl_fecth中，你还可以使用请求对象req。还有个后端响应对象beresp。Beresp包含了后端的HTTP头信息。
varnish 3.X 配置参考文档：http://anykoro.sinaapp.com/?p=261
编辑：/usr/local/varnish/vcl.conf ，文件不存在则创建。注意：Server A 与server B 配置一致！
配置详情如下：
?
###########后台代理服务器########
backend server_osapub_com{
.host = "192.168.4.97";
.port = "82";
}
acl purge {
"localhost";
"127.0.0.1";
}
#############################################
sub vcl_recv {
#################BAN##########################begin
if (req.request == "BAN") {
# Same ACL check as above:
if (!client.ip ~ purge) {
error 405 "Not allowed.";
}
ban("req.http.host == " + req.http.host +
"&& req.url == " + req.url);
error 200 "Ban added";
}
#################BAN##########################end
###############配置域名##################################
if(req.http.host ~ "^server.osapub.com" ||req.http.host ~ ".osapub.com" ) {
#使用哪一组后台服务器
set req.backend = server_osapub_com;
}
##################################################
if (req.restarts == 0) {
if (req.http.x-forwarded-for) {
set req.http.X-Forwarded-For = req.http.X-Forwarded-For + ", " + client.ip;
}
else {
set req.http.X-Forwarded-For = client.ip;
}
}
if (req.http.Accept-Encoding) {
if (req.url ~ "\.(jpg|jpeg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|swf)$") {
remove req.http.Accept-Encoding;
} elsif (req.http.Accept-Encoding ~ "gzip") {
set req.http.Accept-Encoding = "gzip";}
elsif (req.http.Accept-Encoding ~ "deflate") {
set req.http.Accept-Encoding = "deflate";}
else {
remove req.http.Accept-Encoding;
}
}
if (req.http.Cache-Control ~ "no-cache") {
return (pass);
}
if (req.request != "GET" &&
req.request != "HEAD" &&
req.request != "PUT" &&
req.request != "POST" &&
req.request != "TRACE" &&
req.request != "OPTIONS" &&
req.request != "DELETE") {
return (pipe);
}
if (req.request != "GET" && req.request != "HEAD") {
return(pass);
}
if (req.http.Authorization || req.http.Cookie ||req.http.Authenticate) {
return (pass);
}
if (req.request == "GET" && req.url ~ "(?i)\.php($|\?)"){
return (pass);
}
if (req.url ~ "\.(css|jpg|jpeg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|swf)$") {
unset req.http.Cookie;
}
return (lookup);
}
sub vcl_fetch {
set beresp.grace = 5m;
if (beresp.status == 404 || beresp.status == 503 || beresp.status == 500 || beresp.status == 502) {
set beresp.http.X-Cacheable = "NO: beresp.status";
set beresp.http.X-Cacheable-status = beresp.status;
return (hit_for_pass);
}
#决定哪些头不缓存
if (req.url ~ "\.(php|shtml|asp|aspx|jsp|js|ashx)$") {
return (hit_for_pass);
}
if (req.url ~ "\.(jpg|jpeg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|swf)$") {
unset beresp.http.set-cookie;
}
if (beresp.ttl <= 0s) {
set beresp.http.X-Cacheable = "NO: !beresp.cacheable";
return (hit_for_pass);
}
else {
unset beresp.http.expires;
}
return (deliver);
}
sub vcl_deliver {
if (resp.http.magicmarker) {
unset resp.http.magicmarker;
set resp.http.age = "0";
}
# add cache hit data
if (obj.hits > 0) {
set resp.http.X-Cache = "HIT";
set resp.http.X-Cache-Hits = obj.hits;
}
else {
set resp.http.X-Cache = "MISS";
}
# hidden some sensitive http header returning to client, when the cache server received from backend server response
remove resp.http.X-Varnish;
remove resp.http.Via;
remove resp.http.Age;
remove resp.http.X-Powered-By;
remove resp.http.X-Drupal-Cache;
return (deliver);
}
sub vcl_error {
if (obj.status == 503 && req.restarts < 5) {
set obj.http.X-Restarts = req.restarts;
return (restart);
}
}
sub vcl_hit {
if (req.http.Cache-Control ~ "no-cache") {
if (! (req.http.Via || req.http.User-Agent ~ "bot|MSIE")) {
set obj.ttl = 0s;
return (restart);
}
}
return(deliver);
}配置完成后执行：/root/varnish_start.sh 如果启动成功则表示配置无误！
四、 配置nginx编辑： /usr/local/nginx/conf/nginx.conf ，nginx 的配置方法请参考网上文档资料。
Server A（192.168.4.97） nginx配置如下：
?
user www www;
worker_processes 16;
error_log /logs/nginx/nginx_error.log crit;
#Specifies the value for maximum file descriptors that can be opened by this process.
worker_rlimit_nofile 65500;
events
{
use epoll;
worker_connections 65500;
}
http
{
include mime.types;
default_type application/octet-stream;
server_names_hash_bucket_size 128;
client_header_buffer_size 64k;
large_client_header_buffers 4 64k;
client_max_body_size 10m;
server_tokens off;
expires 1h;
sendfile on;
tcp_nopush on;
keepalive_timeout 60;
tcp_nodelay on;
fastcgi_connect_timeout 200;
fastcgi_send_timeout 300;
fastcgi_read_timeout 600;
fastcgi_buffer_size 128k;
fastcgi_buffers 4 64k;
fastcgi_busy_buffers_size 128k;
fastcgi_temp_file_write_size 128k;
fastcgi_temp_path /dev/shm;
gzip on;
gzip_min_length 2048;
gzip_buffers 4 16k;
gzip_http_version 1.1;
gzip_types text/plain text/css application/xml application/x-javascript ;
log_format access '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" $http_x_forwarded_for';
################# include ###################
upstream varnish_server {
server 127.0.0.1:81 weight=2 max_fails=3 fail_timeout=30s;
server 192.168.4.99:81 weight=2 max_fails=3 fail_timeout=30s;
ip_hash;
}
server
{
listen 80;
server_name 192.168.4.96 192.168.4.98;
index index.html index.htm index.php index.aspx;
location /
{
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_connect_timeout 200;
proxy_send_timeout 300;
proxy_read_timeout 500;
proxy_buffer_size 256k;
proxy_buffers 4 128k;
proxy_busy_buffers_size 256k;
proxy_temp_file_write_size 256k;
proxy_temp_path /dev/shm;
proxy_pass http://varnish_server;
expires off;
access_log /logs/nginx/192.168.4.96.log access;
}
}
server
{
listen 82;
server_name 192.168.4.97;
index index.html index.htm index.php;
root /data/web/awstats/www;
location ~ .*\.php$
{
include fcgi.conf;
fastcgi_pass 127.0.0.1:10080;
fastcgi_index index.php;
expires off;
}
access_log /logs/nginx/awstats.osapub.com.log access;
}
}server B （192.168.4.99）配置如下：
?
user www www;
worker_processes 16;
error_log /logs/nginx/nginx_error.log crit;
#Specifies the value for maximum file descriptors that can be opened by this process.
worker_rlimit_nofile 65500;
events
{
use epoll;
worker_connections 65500;
}
http
{
include mime.types;
default_type application/octet-stream;
server_names_hash_bucket_size 128;
client_header_buffer_size 64k;
large_client_header_buffers 4 64k;
client_max_body_size 10m;
server_tokens off;
expires 1h;
sendfile on;
tcp_nopush on;
keepalive_timeout 60;
tcp_nodelay on;
fastcgi_connect_timeout 200;
fastcgi_send_timeout 300;
fastcgi_read_timeout 600;
fastcgi_buffer_size 128k;
fastcgi_buffers 4 64k;
fastcgi_busy_buffers_size 128k;
fastcgi_temp_file_write_size 128k;
fastcgi_temp_path /dev/shm;
gzip on;
gzip_min_length 2048;
gzip_buffers 4 16k;
gzip_http_version 1.1;
gzip_types text/plain text/css application/xml application/x-javascript ;
log_format access '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" $http_x_forwarded_for';
################# include ###################
upstream varnish_server {
server 127.0.0.1:81 weight=2 max_fails=3 fail_timeout=30s;
server 192.168.4.97:81 weight=2 max_fails=3 fail_timeout=30s;
ip_hash;
}
server
{
listen 80;
server_name 192.168.4.96 192.168.4.98;
index index.html index.htm index.php index.aspx;
location /
{
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_connect_timeout 200;
proxy_send_timeout 300;
proxy_read_timeout 500;
proxy_buffer_size 256k;
proxy_buffers 4 128k;
proxy_busy_buffers_size 256k;
proxy_temp_file_write_size 256k;
proxy_temp_path /dev/shm;
proxy_pass http://varnish_server;
expires off;
access_log /logs/nginx/192.168.4.98.log access;
}
}
server
{
listen 82;
server_name 192.168.4.99;
index index.html index.htm index.php;
root /data/web/awstats/www;
location ~ .*\.php$
{
include fcgi.conf;
fastcgi_pass 127.0.0.1:10080;
fastcgi_index index.php;
expires off;
}
access_log /logs/nginx/awstats.osapub.com.log access;
}
}启动nginx:
/root/nginx_start
启动正常会监听80，82端口！
五、 运行nginx ha脚本
server A 的脚本下载地址：http://bbs.osapub.com/down/server_a_ha.tar.gz解压力后得到三个脚本：
nginx_watchdog.sh
nginxha.sh
nginx_ha1.sh
server B 的脚本下载地址：http://bbs.osapub.com/down/server_b_ha.tar.gz解压力后得到三个脚本：
nginx_watchdog.sh
nginxha.sh
nginx_ha2.sh
注意：脚本建议放到：/data/sh/ha 目录下，否则需要修改nginxha.sh 里面的程序路径！
六、 测试1，测试之前先把nginx 负载去掉,可以在前面加#号暂时注释，只保留本机解析，确保测试结果准确。
2，修改本机host文件
添加：192.168.4.99 server.osapub.com 到末尾，保存后访问。
3，正常结果显示如下：
到这里整个架构基本能运行起来了，根据大家的实际需求，对配置文件进行调优，HA脚本也可以进一步调优，关于报警，请参考社区自动安装mutt报警的脚本！
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