Nginx实现负载均衡
在看这个知识点之前，先学会nginx的反向代理
先看nginx的反向代理，就看这个链接：https://blog.csdn.net/weixin_43689480/article/details/95860813
nginx实现负载均衡的过程
想要的结果就是：给 www.sina.com 添加多个tomcat服务器
首先安装两个tomcat服务器，都放到nginx服务器里面，两个端口分别是8081和8082
首先是下载tomcat，使用下面的命令
wget http://mirror.bit.edu.cn/apache/tomcat/tomcat-7/v7.0.94/bin/apache-tomcat-7.0.94.tar.gz
然后是加载这个压缩包
tar -xvf apache-tomcat-7.0.94.tar.gz
然后把apache-tomcat-7.0.94复制成两份，一份是tomcat8081，一份是tomcat8082，过程如下
cp -r apache-tomcat-7.0.94 tomcat8081
cp -r apache-tomcat-7.0.94 tomcat8082
然后通过Editplus远程连接修改tomcat8081里面的server.xml配置里面修改端口号(怎么通过EditPlus连接linux，看着篇文章：https://blog.csdn.net/weixin_43689480/article/details/95867289)，注意下面要修改三个端口号
<Server port="8006" shutdown="SHUTDOWN">
<Connector port="8081" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
<Connector port="8010" protocol="AJP/1.3" redirectPort="8443" />
<?xml version='1.0' encoding='utf-8'?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Note: A "Server" is not itself a "Container", so you may not
define subcomponents such as "Valves" at this level.
Documentation at /docs/config/server.html
-->
<Server port="8006" shutdown="SHUTDOWN">
<Listener className="org.apache.catalina.startup.VersionLoggerListener" />
<!-- Security listener. Documentation at /docs/config/listeners.html
<Listener className="org.apache.catalina.security.SecurityListener" />
-->
<!--APR library loader. Documentation at /docs/apr.html -->
<Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
<!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html -->
<Listener className="org.apache.catalina.core.JasperListener" />
<!-- Prevent memory leaks due to use of particular java/javax APIs-->
<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
<Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
<!-- Global JNDI resources
Documentation at /docs/jndi-resources-howto.html
-->
<GlobalNamingResources>
<!-- Editable user database that can also be used by
UserDatabaseRealm to authenticate users
-->
<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>
<!-- A "Service" is a collection of one or more "Connectors" that share
a single "Container" Note: A "Service" is not itself a "Container",
so you may not define subcomponents such as "Valves" at this level.
Documentation at /docs/config/service.html
-->
<Service name="Catalina">
<!--The connectors can use a shared executor, you can define one or more named thread pools-->
<!--
<Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
maxThreads="150" minSpareThreads="4"/>
-->
<!-- A "Connector" represents an endpoint by which requests are received
and responses are returned. Documentation at :
Java HTTP Connector: /docs/config/http.html (blocking & non-blocking)
Java AJP Connector: /docs/config/ajp.html
APR (HTTP/AJP) Connector: /docs/apr.html
Define a non-SSL HTTP/1.1 Connector on port 8080
-->
<Connector port="8081" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
<!-- A "Connector" using the shared thread pool-->
<!--
<Connector executor="tomcatThreadPool"
port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
-->
<!-- Define a SSL HTTP/1.1 Connector on port 8443
This connector uses the BIO implementation that requires the JSSE
style configuration. When using the APR/native implementation, the
OpenSSL style configuration is required as described in the APR/native
documentation -->
<!--
<Connector port="8443" protocol="org.apache.coyote.http11.Http11Protocol"
maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
clientAuth="false" sslProtocol="TLS" />
-->
<!-- Define an AJP 1.3 Connector on port 8009 -->
<Connector port="8010" protocol="AJP/1.3" redirectPort="8443" />
<!-- An Engine represents the entry point (within Catalina) that processes
every request. The Engine implementation for Tomcat stand alone
analyzes the HTTP headers included with the request, and passes them
on to the appropriate Host (virtual host).
Documentation at /docs/config/engine.html -->
<!-- You should set jvmRoute to support load-balancing via AJP ie :
<Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
-->
<Engine name="Catalina" defaultHost="localhost">
<!--For clustering, please take a look at documentation at:
/docs/cluster-howto.html (simple how to)
/docs/config/cluster.html (reference documentation) -->
<!--
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
-->
<!-- Use the LockOutRealm to prevent attempts to guess user passwords
via a brute-force attack -->
<Realm className="org.apache.catalina.realm.LockOutRealm">
<!-- This Realm uses the UserDatabase configured in the global JNDI
resources under the key "UserDatabase". Any edits
that are performed against this UserDatabase are immediately
available for use by the Realm. -->
<Realm className="org.apache.catalina.realm.UserDatabaseRealm"
resourceName="UserDatabase"/>
</Realm>
<Host name="localhost" appBase="webapps"
unpackWARs="true" autoDeploy="true">
<!-- SingleSignOn valve, share authentication between web applications
Documentation at: /docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.authenticator.SingleSignOn" />
-->
<!-- Access log processes all example.
Documentation at: /docs/config/valve.html
Note: The pattern used is equivalent to using pattern="common" -->
<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>
然后通过Editplus远程连接修改tomcat8082里面的server.xml配置里面修改端口号(怎么通过EditPlus连接linux，看着篇文章：https://blog.csdn.net/weixin_43689480/article/details/95867289)，注意下面要修改三个端口号
<Server port="8007" shutdown="SHUTDOWN">
<Connector port="8082" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
<Connector port="8011" protocol="AJP/1.3" redirectPort="8443" />
<?xml version='1.0' encoding='utf-8'?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Note: A "Server" is not itself a "Container", so you may not
define subcomponents such as "Valves" at this level.
Documentation at /docs/config/server.html
-->
<Server port="8007" shutdown="SHUTDOWN">
<!-- Security listener. Documentation at /docs/config/listeners.html
<Listener className="org.apache.catalina.security.SecurityListener" />
-->
<!--APR library loader. Documentation at /docs/apr.html -->
<Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
<!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html -->
<Listener className="org.apache.catalina.core.JasperListener" />
<!-- Prevent memory leaks due to use of particular java/javax APIs-->
<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
<Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
<!-- Global JNDI resources
Documentation at /docs/jndi-resources-howto.html
-->
<GlobalNamingResources>
<!-- Editable user database that can also be used by
UserDatabaseRealm to authenticate users
-->
<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>
<!-- A "Service" is a collection of one or more "Connectors" that share
a single "Container" Note: A "Service" is not itself a "Container",
so you may not define subcomponents such as "Valves" at this level.
Documentation at /docs/config/service.html
-->
<Service name="Catalina">
<!--The connectors can use a shared executor, you can define one or more named thread pools-->
<!--
<Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
maxThreads="150" minSpareThreads="4"/>
-->
<!-- A "Connector" represents an endpoint by which requests are received
and responses are returned. Documentation at :
Java HTTP Connector: /docs/config/http.html (blocking & non-blocking)
Java AJP Connector: /docs/config/ajp.html
APR (HTTP/AJP) Connector: /docs/apr.html
Define a non-SSL HTTP/1.1 Connector on port 8080
-->
<Connector port="8082" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
<!-- A "Connector" using the shared thread pool-->
<!--
<Connector executor="tomcatThreadPool"
port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
-->
<!-- Define a SSL HTTP/1.1 Connector on port 8443
This connector uses the JSSE configuration, when using APR, the
connector should be using the OpenSSL style configuration
described in the APR documentation -->
<!--
<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
maxThreads="150" scheme="https" secure="true"
clientAuth="false" sslProtocol="TLS" />
-->
<!-- Define an AJP 1.3 Connector on port 8009 -->
<Connector port="8011" protocol="AJP/1.3" redirectPort="8443" />
<!-- An Engine represents the entry point (within Catalina) that processes
every request. The Engine implementation for Tomcat stand alone
analyzes the HTTP headers included with the request, and passes them
on to the appropriate Host (virtual host).
Documentation at /docs/config/engine.html -->
<!-- You should set jvmRoute to support load-balancing via AJP ie :
<Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
-->
<Engine name="Catalina" defaultHost="localhost">
<!--For clustering, please take a look at documentation at:
/docs/cluster-howto.html (simple how to)
/docs/config/cluster.html (reference documentation) -->
<!--
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
-->
<!-- Use the LockOutRealm to prevent attempts to guess user passwords
via a brute-force attack -->
<Realm className="org.apache.catalina.realm.LockOutRealm">
<!-- This Realm uses the UserDatabase configured in the global JNDI
resources under the key "UserDatabase". Any edits
that are performed against this UserDatabase are immediately
available for use by the Realm. -->
<Realm className="org.apache.catalina.realm.UserDatabaseRealm"
resourceName="UserDatabase"/>
</Realm>
<Host name="localhost" appBase="webapps"
unpackWARs="true" autoDeploy="true">
<!-- SingleSignOn valve, share authentication between web applications
Documentation at: /docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.authenticator.SingleSignOn" />
-->
<!-- Access log processes all example.
Documentation at: /docs/config/valve.html
Note: The pattern used is equivalent to using pattern="common" -->
<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>
然后把tomact8081里面的webapps文件夹里面的ROOT文件夹里面的index.jsp变成下面这样，此时可以看到下面输入的内容是8081
<%--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
--%>
<%@ page session="false" %>
<%
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy");
request.setAttribute("year", sdf.format(new java.util.Date()));
request.setAttribute("tomcat7Url", "http://tomcat.apache.org/");
request.setAttribute("tomcat7DocUrl", "/docs/");
request.setAttribute("tomcat7ExamplesUrl", "/examples/");
%>
<html lang="en">
<head>
<title><%=request.getServletContext().getServerInfo() %>title>
<link href="favicon.ico" rel="icon" type="image/x-icon" />
<link href="favicon.ico" rel="shortcut icon" type="image/x-icon" />
<link href="tomcat.css" rel="stylesheet" type="text/css" />
head>
<body>
<h1>tomcat8081index.jsp<h1>
body>
html>
然后把tomact8082里面的webapps文件夹里面的ROOT文件夹里面的index.jsp变成下面这样，此时可以看到下面输入的内容是8082
<%--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
--%>
<%@ page session="false" %>
<%
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy");
request.setAttribute("year", sdf.format(new java.util.Date()));
request.setAttribute("tomcat7Url", "http://tomcat.apache.org/");
request.setAttribute("tomcat7DocUrl", "/docs/");
request.setAttribute("tomcat7ExamplesUrl", "/examples/");
%>
<html lang="en">
<head>
<title><%=request.getServletContext().getServerInfo() %>title>
<link href="favicon.ico" rel="icon" type="image/x-icon" />
<link href="favicon.ico" rel="shortcut icon" type="image/x-icon" />
<link href="tomcat.css" rel="stylesheet" type="text/css" />
head>
<body>
<h1>tomcat8082index.jsp<h1>
body>
html>
然后就是启动tomcat8081和tomcat8082，启动如下所示
/root/tomcat8081/bin/startup.sh
/root/tomcat8082/bin/startup.sh
然后访问http://47.91.248.236:8081/ 路径结果如下，成功了
然后访问http://47.91.248.236:8082/ 路径结果如下，成功了
然后我们配置本地电脑里面的host文件变成下面这样
# Copyright (c) 1993-2009 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host
# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost
47.91.248.236 www.sina.com
然后通过EditPlus配置nginx服务器里面的conf文件夹里面的nginx.conf配置文件，配置完之后记得要重启nginx服务器
怎么通过EditPlus操作nginx服务器里面的nginx.conf配置文件，看这个链接：https://blog.csdn.net/weixin_43689480/article/details/95867289
然后讲解下面的配置：就比如下面的 # tomcat1注释，当访问www.sina.com 的时候，就会访问host文件，然后就会去找47.91.248.236 这个ip对应的linux服务器，然后www.sina.com 默认的端口就是80，所以访问www.sina.com 的时候，就会被下面的蓝色代码给捕获到，然后下面的蓝色代码里面的server就会找到蓝色代码里面的upstream tomcat1里面的server 47.91.248.236:8081和server 47.91.248.236:8082，然后呢因为我们配置配置权重，所以当第一次访问www.sina.com 这个域名的时候，就会先找到8081端口的tomcat服务器，然后当第二次访问www.sina.com 这个域名的时候，就会先找到8082端口的tomcat服务器，然后当第三次访问www.sina.com 这个域名的时候，就会先找到8081端口的tomcat服务器，然后当第四次访问www.sina.com 这个域名的时候，就会先找到8082端口的tomcat服务器，
user root;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/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"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
# tomcat1注释开始
upstream tomcat1 {
server 47.91.248.236:8081;
server 47.91.248.236:8082;
}
server {
listen 80;
server_name www.sina.com;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
proxy_pass http://tomcat1;
index index.html index.htm;
}
}
# tomcat1注释结束
}
然后我们访问 www.sina.com
第一次访问
第二次访问
从上面的结果可以看出来nginx的负载均衡搞定了
Nginx的负载均衡怎么实现不同服务器的访问次数不同
就是用下面的weight属性就好了，默认的每一个服务器的weight都是1，然后weigth的值越大，表示访问该服务器的次数越高，所以如果好一点的服务器，那么我么就把这个服务器的weight的值变大一些，如果服务器差一些，那么就把这个服务器的weight的值变小一些
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/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"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
upstream tomcat1 {
server 47.91.248.236:8081;
server 47.91.248.236:8082 weight 2;
}
server {
listen 80;
server_name www.sina.com.cn;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
proxy_pass http://tomcat1;
index index.html index.htm;
}
}
}
能看到这里的同学，就帮忙点个赞吧，Thanks♪(･ω･)ﾉ