nginx、tomcat下载安装本篇不提了，直接说步骤：
1 配置nginx配置文件：
nginx下conf文件夹中的nginx.conf 添加下面代码，
upstream web_apps{
server 127.0.0.1:8080 weight=1;
server 127.0.0.1:8989 weight=1;
}
server {
listen 80;
server_name localhost 127.0.0.1;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Requested-For $remote_addr;
proxy_set_header REMOTE-HOST $remote_addr;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
location / {
root html;
index index.html;
proxy_pass http://web_apps;
proxy_connect_timeout 600;
proxy_read_timeout 600;
}
}
2配置tomcat 配置文件：
修改tomcat下conf中 server.xml
多个tomcat 中有3地方要不能冲突：
<!-- 1-->
<Server port="19999" shutdown="SHUTDOWN">
<!-- 2 -->
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443"/>
<!-- 3 -->
<Connector port="9999" protocol="AJP/1.3" redirectPort="8443" />
port可以设大一点。
然后每个加上tomcat自带的session同步 找到<Engine name="Catalina" defaultHost="localhost">关键句下面添加
<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="228.0.0.4"
port="45564"
frequency="500"
dropTime="3000"/>
<Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
address="auto"
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.MessageDispatchInterceptor"/>
</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.ClusterSessionListener"/>
</Cluster>
然后把tomcat初始页码换一下方便测试效果，在apache-tomcat\webapps\ROOT 更改index.jsp内容为
<html>
<head>
<title> test</title>
</head>
<body>
SessionID is <%=session.getId()%>
<br/>
SessionIP is <%=request.getServerName()%>
<br/>
SessionPort is <%=request.getServerPort()%>
<!-- 端口号依次修改为：8080/8989-->
<h1>tomcat_8080</h1>
</body>
</html>
然后分别启动tomcat 和nginx 。
直接输入localhost就如下图
或者是这样：
tomcat服务器会被nginx切换 但sessionID没有变。
另外说个nginx个操作指令 ：cmd黑窗口进入nginx目录输入 nginx -s reload 会重新载入nginx的配置文件，不用重启nginx.
如果出现异常先去看log文件 tomcat和nginx日志很详细。比如我遇到的：
19-Jun-2019 10:42:12.779 警告 [main] org.apache.catalina.startup.Catalina.load Unable to load server configuration from [D:\apache-tomcat-9.0.17\conf\server.xml]
org.xml.sax.SAXParseException; systemId: file:/D:/apache-tomcat-9.0.17/conf/server.xml; lineNumber: 154; columnNumber: 113; Error at line [154] column [113]: [org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor]
at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:1855)
at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:1887)
at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1176)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:509)
at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:182)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1339)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2784)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:842)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:771)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1431)
at org.apache.catalina.startup.Catalina.load(Catalina.java:567)
at org.apache.catalina.startup.Catalina.load(Catalina.java:608)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:306)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:491)
Caused by: java.lang.ClassNotFoundException: org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.apache.tomcat.util.digester.ObjectCreateRule.begin(ObjectCreateRule.java:115)
at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1173)
... 20 more
这个包已过时不在了，配上去肯定不行。。
参考博客：
https://www.cnblogs.com/beyang/p/9122406.html
https://blog.csdn.net/qq_23832313/article/details/83578813
over~