实验目标：
实现通过haproxy轮询调度（RR）反代至两台lamp时，用户会话ID保持不变。
版本：
haproxy-1.5.4-3.el6.x86_64，yum安装
memcached-1.4.15-9.el7_2.1.x86_64，yum安装
LAMP：httpd-2.4.9、mariadb-5.5.36-linux-x86_64、php-5.4.26，都是编译安装。
php的memcache扩展模块：memcache-2.2.7，编译安装
PHP安装：（其他安装略过）
编译成php-fpm
./configure --prefix=/usr/local/php-5.2.26 --with-mysql=/usr/local/mysql --with-openssl --with-mysqli=/usr/local/mysql/bin/mysql_config --enable-mbstring --with-freetype-dir --with-jpeg-dir --with-png-dir --with-zlib --with-libxml-dir=/usr --enable-xml --enable-sockets --enable-fpm --with-mcrypt --with-config-file-path=/etc --with-config-file-scan-dir=/etc/php-5.2.26 --with-bz2
memcache 扩展模块安装
tar xf memcache-2.2.7.tgz
cd memcache-2.2.7
/usr/local/php-5.2.26/bin/phpize
Configuring for:
PHP Api Version: 20100412
Zend Module Api No: 20100525
Zend Extension Api No: 220100525
./configure --with-php-config=/usr/local/php/bin/php-config --enable-memcache
make && make install
上述安装完后会有类似以下的提示：
Installing shared extensions: /usr/local/php-5.2.26/lib/php/extensions/no-debug-non-zts-20100525/memcache.so
编辑/etc/php.ini，在“Dynamic Extensions”相关的位置添加如下一行来载入memcache扩展：
extension=/usr/local/php/lib/php/extensions/no-debug-non-zts-20090626/memcache.so
httpd虚拟机配置：（只展示其中一台的配置）
cat /etc/httpd-2.4.9/extra/httpd-vhosts.conf:
<VirtualHost 192.168.1.30:80>
DocumentRoot "/www/test1.com"
ErrorLog "logs/dummy-test1.com-error_log"
CustomLog "logs/dummy-test1.com-access_log" common
<Directory /www/test1.com>
require all granted
</Directory>
ProxyRequests Off
ProxyPassMatch ^/(.*\.php)$ fcgi://192.168.1.30:9000/www/test1.com/$1
</VirtualHost>
httpd启用PHP及启动导入虚拟机配置：
启动以下两个模块：
LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_fcgi_module modules/mod_proxy_fcgi.so
修改：
DirectoryIndex index.php index.html
添加：
Include /etc/httpd-2.4.9/extra/httpd-vhosts.conf
AddType application/x-httpd-php-source .phps
AddType application/x-httpd-php .php
测试php与memcache的连接是否成功：
cat /www/test1/01.php:
<?php
$mem = new Memcache;
$mem->connect("192.168.1.25", 11211) or die("Could not connect");
$version = $mem->getVersion();
echo "Server's version: ".$version."<br/>\n";
$mem->set('hellokey', 'Hello World', 0, 600) or die("Failed to save data at the memcached server");
echo "Store data in the cache (data will expire in 600 seconds)<br/>\n";
$get_result = $mem->get('hellokey');
cho "$get_result is from memcached server.";
?>访问此01.php，出现“Hello World is from memcached server”时，说明表memcache与php连接成功。
修改/etc/php.ini，把会话保存到memcache中。
session.save_handler = memcache
session.save_path="tcp://192.168.1.25:11211"
haproxy配置：
frontend main *:80
default_backend app
backend app
balance roundrobin
server app1 192.168.1.13:80 check
server app2 192.168.1.30:80 check
测试会话保存是否成功：
192.168.1.13（lamp）的测试脚本：/www/test1.com/02.php
<?php
session_start();
if (!isset($_SESSION['admin'])) {
$_SESSION['TEST'] = 'wan';
}
print $_SESSION['admin'];
print "\n";
print session_id();
print "\n";
print "===> 192.168.1.13 web server";
?>192.168.1.30（lamp）的测试脚本：/www/test1.com/02.php
<?php
session_start();
if (!isset($_SESSION['admin'])) {
$_SESSION['TEST'] = 'wan';
}
print $_SESSION['admin'];
print "\n";
print session_id();
print "\n";
echo "===> 192.168.1.30 web server"
?>区别在于最后一行print 显示lamp本身的IP地址。
浏览器访问02.php
