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 "%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="">
<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 "%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 , :: 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；