Configured in tomcat's server.xml

1. <Connectorport="8080"protocol="HTTP/1.1"connectionTimeout="20000"redirectPort="8443"maxSpareThreads="750"maxThreads="1000"minSpareTHreads="50"acceptCount="1000"maxProcessors="1000"URIEncoding="gbk"useBodyEncodingForURI="true"/>                的配置, 其中:

   acceptCount="1000" the maximum number of connections accepted

    maxProcessors="1000" Maximum number of active threads

   port="8080" service port

   protocol="HTTP/1.1" service protocol

   connectionTimeout="20000" The timeout unit is ms

   redirectPort="8443" When the redirect port  requires secure communication, the client request will be forwarded to the redirectPort port of SSL

   maxThreads: The maximum number of threads that Tomcat can create, each thread handles one request;  maxThreads determines the maximum thread threshold of tomcat, which needs to be set larger

   minSpareThreads: The minimum number of spare threads, the number of initialized threads when tomcat starts;

   maxSpareThreads: The maximum number of spare threads. Once the created threads exceed this value, Tomcat will close the socket threads that are no longer needed;

   
   

    URIEncoding="gbk" sets the default transcoding format of tomcat

   Check out the documentation in $TOMCAT_HOME/webapps/tomcat-docs/config/http.html for the following instructions: 
   URIEncoding: This specifies the character encoding used to decode the URI bytes, after %xx decoding the URL. If not specified, ISO- 8859-1 will be used. That is to say, if URIEncoding is not set, Tomcat will perform URL decoding according to ISO-8859-1 by default. ISO-8859-1 does not include Chinese characters, so Chinese characters must not be parsed correctly. .

   
   

   Reprint someone else's blog:

    

   1. Tomcat connection pool configuration 
        If Tomcat wants to withstand a large amount of concurrency, the number of connections must be increased. The general Tomcat Connector can be modified as follows: 
        

   <Connector port="80" protocol="HTTP/1.1" 
       connectionTimeout="60000" 
       redirectPort="8443"
       maxThreads="5000" 
       acceptCount="500"
       minSpareThreads="100"
       maxSpareThreads="5000"
       enableLookups="false"
       compression="on"
       compressionMinSize="2048"
       compressableMimeType="text/html,text/xml,text/javascript,text/css,text/plain"
       disableUploadTimeout="true"
       URIEncoding="UTF-8"/>

   其中几个关键的参数: 
   connectionTimeout:连接超时,毫秒为单位.对于高并发对实时要求不高的可以使适当增加该值 
   maxThreads:最大并发连接数 
   acceptCount:在超过最大连接数后,可以接受的排队数量 
   minSpareThreads:Tomcat初始化时默认创建的线程数,也是以后线程增加时一次增加的最小数量 
   maxSpareThreads:这个参数标识,一旦创建的线程数量超过这个值,Tomcat就会关闭不活动的线程 
   enableLookups:关闭DNS查询 
   在实现中,我们发现使用该配置,连接数上去之后很难下降,导致CPU一直维持在一个比较高的水平. 
   
   后来我们换了一种连接方式,采用线程池的方式,首先定义一个Executor: 

   <Executor name="tomcatThreadPool" 
           namePrefix="tomcatThreadPool-" 
           maxThreads="1000" 
           maxIdleTime="300000"
           minSpareThreads="200"/>

   
   参数的意义和上述相同 
   在Connector中使用定义的这个连接池: 
   

    

   <Connector executor="tomcatThreadPool"
              port="20003" protocol="HTTP/1.1"
              acceptCount="800"
              minProcessors="300"
              maxProcessors = "1000"
              redirectPort="8443"/>

    

   minProcessors,maxProcessors与上面的minSpareThreads,maxThreads意义差不多. 
   使用连接池以后,发现连接数上升后如果一段时间没有请求了,连接数会很快下降,CPU的消耗得到了有效的降低, 
   处理能力得到了增强.

   
   

   
   

   
   

   
   

   
   

   如何查看当前tomcat的连接数呢?

   假设服务器上开启了 2个tomcat实例,分别监听8040和8050端口

   netstat -na | grep ESTAB | grep 8040 | wc -l
   
   netstat -na | grep ESTAB | grep 8050 | wc -l

   
   

   二者之和,就是所有tomcat的连接数