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
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；
