nginx+tomcat+memcache实现负载均衡

实验环境

redhat6.5
iptables和selinux关闭
Server2：172.25.254.2:tomcat1,nginx,memcached
Server1：172.25.254.1:tomcat2,memcached

Tomcat1(T1)将session存储在 memcached2 (T2)上。只有当 M2不可用时,T1才将 session 存储在 memcached1 上(M1是T1 failoverNode)。使用这种配置的好处是,当T1和M1同时崩溃时也不会丢失 session会话,避免单点故障。

 

 

 

server1,server2：
[root@server1 ~]# tar zxf jdk-7u79-linux-x64.tar.gz -C /usr/local
[root@server1 ~]# ln -s /usr/local/jdk1.7.0_79/ /usr/local/jdk
[root@server1 ~]# vim /etc/profile

 export JAVA_HOME=/usr/local/jdk
 export CLASSPATH=.:$JAVA_HOME/lib:$JAVA_HOME/jre/lib   
 export PATH=$PATH:$JAVA_HOME/bin   //$PATH系统原变量
[root@server5 ~]# source /etc/profile
测试java:
[root@server1 ~]# which java
/usr/local/jdk/bin/java
[root@server1 ~]# which javac
/usr/local/jdk/bin/javac
[root@server1 ~]# vim test.java
public class test
{
        public static void main(String[] args)
        {
                System.out.println("hello world");
        }
}
[root@server1~]# javac test.java
[root@server1 ~]# java test
hello world

安装tomcat：
[root@server1 ~]# tar zxf apache-tomcat-7.0.37.tar.gz
[root@server1 ~]# mv apache-tomcat-7.0.37 /usr/local/tomcat
[root@server1 ~]# cd /usr/local/tomcat/apache-tomcat-7.0.37
[root@server1 apache-tomcat-7.0.37]# mv * ..
[root@server1 apache-tomcat-7.0.37]# cd
[root@server1 ~]# mv jar /usr/local/tomcat/lib/
[root@server1 ~]# cd /usr/local/tomcat/lib/jar
[root@server1 jar]# mv * ..
[root@server1 jar]# cd ..
[root@server1 lib]# ls  //查看含有如下文件
asm-3.2.jar                  memcached-session-manager-tc7-1.6.3.jar
kryo-1.04.jar                            
minlog-1.2.jar
kryo-serializers-0.10.jar                
msm-kryo-serializer-1.6.3.jar
memcached-session-manager-1.6.3.jar      
reflectasm-1.01.jar
spymemcached-2.7.3.jar
[root@server1 lib]# vim /usr/local/tomcat/conf/context.xml
 ......
 34  35         memcachedNodes="n1:172.25.254.1:11211,n2:172.25.254.2:11211"
 36         failoverNodes="n1"  //在server2上此项设置为“n2”
 37         requestUriIgnorePattern=".*\.(ico|png|gif|jpg|css|js)$"
 38         transcoderFactoryClass="de.javakaffee.web.msm.serializer.kryo.KryoTransco    derFactory"
 39 />
 ......

[root@server1 lib]# /usr/local/tomcat/bin/startup.sh  //开启tomcat

安装memcached:server1,server2
[root@server1 ~]# yum install memcached -y
[root@server1 ~]# /etc/init.d/memcached start  //开启memcached服务 

在server2上源码编译安装nginx，上篇已经详细讲解

安装完成具体配置

 

[root@server2 conf]# vim nginx.conf
  2 user nginx nginx;
  3 worker_processes  1;
 12 events {
 13     worker_connections  1024;
 17 http {
 18     include       mime.types;
 19     default_type  application/octet-stream;
 20         upstream tomcat{
 21                 sticky;  
 22                 server 172.25.254.1:8080;
 23                 server 172.25.254.2:8080;
 24         }
 32     sendfile        on;
 33     tcp_nopush     on;
 36     keepalive_timeout  65;
 37
 38     gzip  on;
 39
 40     server {
 41         listen       80;
 42         server_name  tomcat;
 48         location / {
 49             root   html;
 50             index  index.html index.htm;
 51         }
 57         error_page   500 502 503 504  /50x.html;
 58         location = /50x.html {
 59             root   html;
 60         }
 61         location ~ \.jsp$ {
 62                 proxy_pass http://tomcat;
 63         }
// nginx-sticky-module 为 nginx 的第三方模块,使 nginx 支持 sticky 模式,所谓 sticky 模式就是指同一个用户的访问请求都被发送到同一个 tomcat 实例上处理。
[root@server2 ~]# nginx -t

 

测试：

静态测试：

[root@server1 ~]# cd /usr/local/tomcat/webapps/ROOT/
[root@server1 ROOT]# vim ying.jsp
The time is:<%=new java.util.Date() %>

动态测试：

[root@server1 ROOT]# vim test.jsp  //T1和T2都添加
<%@ page contentType="text/html; charset=GBK" %>
<%@ page import="java.util.*" %>


Server Info:
<%
out.println(request.getLocalAddr() + " : " + request.getLocalPort()+"
");%>
<%
out.println("
ID " + session.getId()+"
");
String dataName = request.getParameter("dataName");
if (dataName != null && dataName.length() > 0) {
String dataValue = request.getParameter("dataValue");
session.setAttribute(dataName, dataValue);
}
out.print("Session list");
Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String)e.nextElement();
String value = session.getAttribute(name).toString();
out.println( name + " = " + value+"
");
System.out.println( name + " = " + value);
}
%>

name:


key:

测试：
[root@server1 ~]# cd /usr/local/tomcat/logs
[root@server1 logs]# cat catalina.out  //查看日志显示session加载好了
INFO: MemcachedSessionService finished initialization, sticky true, operation timeout 1000, with node ids [n1] and failover node ids [n2]

 说明：down掉当前正在响应的 tomcat实例，nginx会自动把用户的请求调度到另一个tomcat实例上,同时session 也没有丢掉。