NGINX如何反向代理Tomcat并且实现Session保持

2022-02-21 21:05:26

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

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

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..tar.gz -C /usr/local/

cd /usr/local/

ln -sv apache-tomcat-7.0./ 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:

# 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 $ 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

  exec $CATALINA_HOME/bin/catalina.sh start ;;

*)

  echo "Usage: `basename $0` {start|stop|restart}"

  exit

  ;;

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="" 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="" protocol="HTTP/1.1"

               connectionTimeout=""

               redirectPort="" />

    <Connector port="" protocol="AJP/1.3" redirectPort="" />

    <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="">

      <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  ;

error_log  /var/log/nginx/nginx.error.log;

pid        /var/run/nginx.pid;

events {

    worker_connections  ;

}

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  ;

    fastcgi_cache_path /www/cache levels=: keys_zone=fcgicache:10m inactive=5m;

    server {

        listen       ;

        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       ;

        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 ;

gzip_buffers  8k;

gzip_http_version 1.1;

gzip_types text/plain text/css application/x-javascript text/xml application/xml;

gzip_disable msie6;

    }

    server {

        listen       ;

        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

    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/

    option                  redispatch

    retries

    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

listen stats

    mode http

    bind 0.0.0.0:

    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 *:

    mode http

    log global

    option httpclose

    option logasap

    option dontlognull

    capture request  header Host len

    capture request  header Referer len

    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: check maxconn

    server img-srv2 192.168.0.35: check maxconn

backend static_servers

    cookie node insert nocache

    option httpchk HEAD /health_check.html

    server static-srv1 192.168.0.25: check maxconn  cookie static-srv1

    server static-srv2 192.168.0.35: check maxconn  cookie static-srv2

backend dynamic_servers

    balance roundrobin

    server tomcat1 192.168.0.25: check maxconn

    server tomcat2 192.168.0.35: check maxconn

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: 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: check port

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

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: check maxconn  cookie tomcat1

    server tomcat2 192.168.0.35: check maxconn  cookie tomcat2

访问验证

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="" 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="" protocol="HTTP/1.1"

               connectionTimeout=""

               redirectPort="" />

    <Connector port="" protocol="AJP/1.3" redirectPort="" />

    <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="">

          <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=""

                        frequency=""

                        dropTime=""/>

            <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.

                      port=""

                      autoBind=""

                      selectorTimeout=""

                      maxThreads=""/>

            <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 ,  :: 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

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

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；

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