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NGINX如何反向代理Tomcat并且实现Session保持

2016-07-29 00:00 966 查看
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-7.0.42.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 "%r" %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 "%r" %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









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





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 "%r" %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 "%r" %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





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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