NGINX如何反向代理Tomcat并且实现Session保持

简介

LNMT=Linux+Nginx+MySQL+Tomcat;

Tomcat 服务器是一个免费的开放源代码的Web 应用服务器,属于轻量级应用服务器;

在中小型系统和并发访问用户不是很多的场合下被普遍使用,是开发和调试JSP 程序的首选;

 

架构需求

Tomcat实现JSP动态请求解析的基本架构

wKioL1NrqMnjx4uUAAKZ_TrMPLU912.jpg

说明:由后端Tomcat负责解析动态jsp请求,但为了提高响应性能,在同一主机内配置Nginx做反向代理,转发所有请求至tomcat即可;

完整的LNMT架构设计

wKiom1NrqReyIsVnAAXyNugPRuA080.jpg

说明:本篇博客主要讲解单台Haproxy到后端多台Tomcat服务器的实现;

 

安装配置

Tomcat安装配置

安装JDK

rpm -ivh jdk-7u9-linux-x64.rpm
vi /etc/profile.d/java.sh
    export JAVA_HOME=/usr/java/latest
    export PATH=$JAVA_HOME/bin:$PATH
. /etc/profile.d/java.sh

 

安装Tomcat

tar xf apache-tomcat-7.0.42.tar.gz -C /usr/local/
cd /usr/local/
ln -sv apache-tomcat-7.0.42/ tomcat
vi /etc/profile.d/tomcat.sh
    export CATALINA_HOME=/usr/local/tomcat
    export PATH=$CATALINA_HOME/bin:$PATH
. /etc/profile.d/tomcat.sh
# 编写服务脚本
vi /etc/init.d/tomcat
#!/bin/sh
# Tomcat init script for Linux.
#
# chkconfig: 2345 96 14
# description: The Apache Tomcat servlet/JSP container.
# JAVA_OPTS='-Xms64m -Xmx128m'
JAVA_HOME=/usr/java/latest
CATALINA_HOME=/usr/local/tomcat
export JAVA_HOME CATALINA_HOME
case $1 in
start)
  exec $CATALINA_HOME/bin/catalina.sh start ;;
stop)
  exec $CATALINA_HOME/bin/catalina.sh stop;;
restart)
  $CATALINA_HOME/bin/catalina.sh stop
  sleep 2
  exec $CATALINA_HOME/bin/catalina.sh start ;;
*)
  echo "Usage: `basename $0` {start|stop|restart}"
  exit 1
  ;;
esac
==========
chmod +x /etc/init.d/tomcat

配置Tomcat

cd /usr/local/tomcat/conf
vi server.xml
<?xml version='1.0' encoding='utf-8'?>
<Server port="8005" shutdown="SHUTDOWN">
  <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
  <Listener className="org.apache.catalina.core.JasperListener" />
  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
  <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
  <Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
  <GlobalNamingResources>
    <Resource name="UserDatabase" auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
  </GlobalNamingResources>
  <Service name="Catalina">
    <Connector port="9000" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
    <Engine name="Catalina" defaultHost="localhost">
      <Realm className="org.apache.catalina.realm.LockOutRealm">
        <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
               resourceName="UserDatabase"/>
      </Realm>
      <Host name="xxrenzhe.lnmmp.com"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">
            <Context path="" docBase="lnmmpapp" />
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="lnmmp_access_log." suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" />
      </Host>
      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log." suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" />
      </Host>
    </Engine>
  </Service>
</Server>
# 创建应用程序相关目录
cd /usr/local/tomcat/webapps/
mkdir -pv lnmmpapp/WEB-INF/{classes,lib}
cd lnmmpapp
vi index.jsp
<%@ page language="java" %>
<html>
  <head><title>Tomcat1</title></head># 在Tomcat2主机上替换为Tomcat2
  <body>
    <h1><font color="red">Tomcat1.lnmmp.com</font></h1>#  在Tomcat2主机上替换为Tomcat2.lnmmp.com,color修改为blue
    <table align="centre" border="1">
      <tr>
        <td>Session ID</td>
    <% session.setAttribute("lnmmp.com","lnmmp.com"); %>
        <td><%= session.getId() %></td>
      </tr>
      <tr>
        <td>Created on</td>
        <td><%= session.getCreationTime() %></td>
     </tr>
    </table>
  </body>
</html>

启动Tomcat服务

chkconfig --add tomcat
service tomcat start

Nginx配置

Nginx安装详见博文“如何测试Nginx的高性能

配置Nginx

vi /etc/nginx/nginx.conf
worker_processes  2;
error_log  /var/log/nginx/nginx.error.log;
pid        /var/run/nginx.pid;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
    default_type  application/octet-stream;
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';
    sendfile        on;
    keepalive_timeout  65;
    fastcgi_cache_path /www/cache levels=1:2 keys_zone=fcgicache:10m inactive=5m;
    server {
        listen       4040;
        server_name  xxrenzhe.lnmmp.com;
        access_log  /var/log/nginx/nginx-img.access.log  main;
root /www/lnmmp.com;
valid_referers none blocked xxrenzhe.lnmmp.com *.lnmmp.com;
if ($invalid_referer) {
rewrite ^/ http://xxrenzhe.lnmmp.com/404.html;
}
    }
    server {
        listen       80;
        server_name  xxrenzhe.lnmmp.com;
        access_log  /var/log/nginx/nginx-static.access.log  main;
        location / {
            root   /www/lnmmp.com;
            index  index.php index.html index.htm;
        }
gzip on;
gzip_comp_level 6;
gzip_buffers 16 8k;
gzip_http_version 1.1;
gzip_types text/plain text/css application/x-javascript text/xml application/xml;
gzip_disable msie6;
    }
    server {
        listen       8080;
        server_name  xxrenzhe.lnmmp.com;
        access_log  /var/log/nginx/nginx-tomcat.access.log  main;
        location / {
proxy_pass http://127.0.0.1:9000;  # 将全部动态请求都转发至后端tomcat
        }
    }
}

启动服务

service nginx start

Haproxy安装配置

yum -y install haproxy
vi /etc/haproxy/haproxy.cfg
global
    log         127.0.0.1 local2
    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user         haproxy
    group       haproxy
    daemon
defaults
    mode                   http
    log                     global
    option                  httplog
    option                  dontlognull
    option http-server-close
    option forwardfor except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 30000
listen stats
    mode http
    bind 0.0.0.0:1080
    stats enable
    stats hide-version
    stats uri     /haproxyadmin?stats
    stats realm   Haproxy\ Statistics
    stats auth    admin:admin
    stats admin if TRUE
frontend http-in
    bind *:80
    mode http
    log global
    option httpclose
    option logasap
    option dontlognull
    capture request  header Host len 20
    capture request  header Referer len 60
    acl url_img         path_beg       -i /images
    acl url_img          path_end       -i .jpg .jpeg .gif .png
    acl url_dynamic      path_end       -i .jsp .do
    use_backend img_servers if url_img
    use_backend dynamic_servers if url_dynamic
    default_backend static_servers
backend img_servers
    balance roundrobin
    server img-srv1 192.168.0.25:4040 check maxconn 6000
    server img-srv2 192.168.0.35:4040 check maxconn 6000
backend static_servers
    cookie node insert nocache
    option httpchk HEAD /health_check.html
    server static-srv1 192.168.0.25:80 check maxconn 6000 cookie static-srv1
    server static-srv2 192.168.0.35:80 check maxconn 6000 cookie static-srv2
backend dynamic_servers
    balance roundrobin
    server tomcat1 192.168.0.25:8080 check maxconn 1000
    server tomcat2 192.168.0.35:8080 check maxconn 1000
server <name> <address>[:port] [param*]
为后端声明一个server,因此,不能用于defaults和frontend区段。
<name>:为此服务器指定的内部名称,其将出现在日志及警告信息中;如果设定了"http-send-server-name",它还将被添加至发往此服务器的请求首部中;
<address>:此服务器的的IPv4地址,也支持使用可解析的主机名,只不过在启动时需要解析主机名至相应的IPv4地址;
[:port]:指定将连接请求所发往的此服务器时的目标端口,其为可选项;未设定时,将使用客户端请求时的同一相端口;
[param*]:为此服务器设定的一系参数;其可用的参数非常多,具体请参考官方文档中的说明,下面仅说明几个常用的参数;
服务器或默认服务器参数:
backup:设定为备用服务器,仅在负载均衡场景中的其它server均不可用于启用此server;
check:启动对此server执行健康状态检查,其可以借助于额外的其它参数完成更精细的设定,如:
inter <delay>:设定健康状态检查的时间间隔,单位为毫秒,默认为2000;也可以使用fastinter和downinter来根据服务器端状态优化此时间延迟;
rise <count>:设定健康状态检查中,某离线的server从离线状态转换至正常状态需要成功检查的次数;
fall <count>:确认server从正常状态转换为不可用状态需要检查的次数;
cookie <value>:为指定server设定cookie值,此处指定的值将在请求入站时被检查,第一次为此值挑选的server将在后续的请求中被选中,其目的在于实现持久连接的功能;
maxconn <maxconn>:指定此服务器接受的最大并发连接数;如果发往此服务器的连接数目高于此处指定的值,其将被放置于请求队列,以等待其它连接被释放;
maxqueue <maxqueue>:设定请求队列的最大长度;
observe <mode>:通过观察服务器的通信状况来判定其健康状态,默认为禁用,其支持的类型有“layer4”和“layer7”,“layer7”仅能用于http代理场景;
redir <prefix>:启用重定向功能,将发往此服务器的GET和HEAD请求均以302状态码响应;需要注意的是,在prefix后面不能使用/,且不能使用相对地址,以免造成循环;例如:
server srv1 172.16.100.6:80 redir http://imageserver.magedu.com check
weight <weight>:权重,默认为1,最大值为256,0表示不参与负载均衡;
检查方法:
option httpchk
option httpchk <uri>
option httpchk <method> <uri>
option httpchk <method> <uri> <version>:不能用于frontend段,例如:
backend https_relay
mode tcp
option httpchk OPTIONS * HTTP/1.1\r\nHost:\ www.magedu.com
server apache1 192.168.1.1:443 check port 80

启动服务

service haproxy start

本地DNS解析设置

xxrenzhe.lnmmp.com A 172.16.25.109 # 配置为haproxy的IP地址即可

访问验证

wKioL1Nrq1nB5OdXAALLOgv4fJM431.jpg

wKiom1Nrq6SCsO8mAALN8_JzTYI243.jpg

说明:由于前端Haproxy调度动态请求是roundrobin算法,故每次刷新都会轮询分配到不同的Tomcat节点上,且每次获得的session都是不一样的;

实现session绑定

将同一用户的请求调度至后端同一台Tomcat上,不至于一刷新就导致session丢失;

修改Tomcat配置

vi /usr/local/tomcat/conf/server.xml
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1"> # 在Tomcat2上替换为tomcat2

 

 

修改Haproxy配置

vi /etc/haproxy/haproxy.cfg
backend dynamic_servers
    cookie node insert nocache
    balance roundrobin
    server tomcat1 192.168.0.25:8080 check maxconn 1000 cookie tomcat1
    server tomcat2 192.168.0.35:8080 check maxconn 1000 cookie tomcat2

访问验证

wKioL1NrrEOyj3ffAALgfNO9W3A279.jpg

说明:当第一次访问成功后,再次刷新并不会改变分配的Tomcat节点和session信息,说明session绑定成功;

 

实现session保持

Tomcat支持Session集群,可在各Tomcat服务器间复制全部session信息,当后端一台Tomcat服务器宕机后,Haproxy重新调度用户请求后,在其它正常的Tomcat服务上依然存在用户原先的session信息;

Session集群可在Tomcat服务器规模(一般10台以下)不大时使用,否则会导致复制代价过高;

配置实现

vi /usr/local/tomcat/conf/server.xml # 完整配置
<?xml version='1.0' encoding='utf-8'?>
<Server port="8005" shutdown="SHUTDOWN">
  <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
  <Listener className="org.apache.catalina.core.JasperListener" />
  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
  <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
  <Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
  <GlobalNamingResources>
    <Resource name="UserDatabase" auth="Container"
              type="org.apache.catalina.UserDatabase"
              description="User database that can be updated and saved"
              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
              pathname="conf/tomcat-users.xml" />
  </GlobalNamingResources>
  <Service name="Catalina">
    <Connector port="9000" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
    <Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1"># 在Tomcat2主机上替换为tomcat2
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
                 channelSendOptions="8">
          <Manager className="org.apache.catalina.ha.session.DeltaManager"
                   expireSessionsOnShutdown="false"
                   notifyListenersOnReplication="true"/>
          <Channel className="org.apache.catalina.tribes.group.GroupChannel">
            <Membership className="org.apache.catalina.tribes.membership.McastService"
                        address="228.25.25.4"
                        port="45564"
                        frequency="500"
                        dropTime="3000"/>
            <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
                      address="192.168.0.25"# 在Tomcat2主机上替换为192.168.0.35
                      port="4000"
                      autoBind="100"
                      selectorTimeout="5000"
                      maxThreads="6"/>
            <Sender className="org.apache.catalina.tribes.transport.ReplicationTransmitter">
              <Transport className="org.apache.catalina.tribes.transport.nio.PooledParallelSender"/>
            </Sender>
            <Interceptor className="org.apache.catalina.tribes.group.interceptors.TcpFailureDetector"/>
            <Interceptor className="org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor"/>
          </Channel>
          <Valve className="org.apache.catalina.ha.tcp.ReplicationValve"
                 filter=""/>
          <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/>
          <Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer"
                    tempDir="/tmp/war-temp/"
                    deployDir="/tmp/war-deploy/"
                    watchDir="/tmp/war-listen/"
                    watchEnabled="false"/>
          <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/>
          <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/>
        </Cluster>
      <Realm className="org.apache.catalina.realm.LockOutRealm">
        <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
               resourceName="UserDatabase"/>
      </Realm>
      <Host name="xxrenzhe.lnmmp.com"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">
            <Context path="" docBase="lnmmpapp" />
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="lnmmp_access_log." suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" />
      </Host>
      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">
        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log." suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" />
      </Host>
    </Engine>
  </Service>
</Server>
cd /usr/local/tomcat/webapps/lnmmpapp/WEB-INF/
cp /usr/local/tomcat/conf/web.xml .
vi web.xml # 添加如下一行,无需放置于任何容器中
<distributable\>

查看日志

# tailf /usr/local/tomcat/logs/catalina.out
May 08, 2014 11:08:13 PM org.apache.catalina.ha.tcp.SimpleTcpCluster memberAdded
INFO: Replication member added:org.apache.catalina.tribes.membership.MemberImpl[tcp://{192, 168, 0, 35}:4000,{192, 168, 0, 35},4000, alive=1029, securePort=-1, UDP Port=-1, id={106 35 -62 -54 -28 61 74 -98 -86 -11 -69 104 28 -114 32 -69 }, payload={}, command={}, domain={}, ]
# 查看到如上信息,则说明session集群已生效,tomcat1已检测到tomcat2节点的存在

 

访问验证

第一次访问

wKioL1NrraHj1dGrAAKnUnDbem8056.jpg

然后停止tomcat1的nginx服务(service nginx stop),再次访问

wKiom1NrriChIXusAALXeQXr7wo656.jpg

说明:虽然因为tomcat1故障,导致用户请求被调度到了tomcat2节点上,但Session ID并未发生改变,即session集群内的所有节点都保存有全局的session信息,很好的实现了用户访问的不中断;

posted @ 2014-05-09 10:54 想想宝宝 阅读(...) 评论(...) 编辑 收藏
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