Tomcat优化

-----------------------------------------------------服务器优化-----------------------------------------------------------------------------------------------------------------------

Tomcat优化:

	1.内存优化(JVM优化)
    vi ./bin/catalina.sh  --> JAVA_OPTS="-server -Xms2048M -Xmx2048M -XX:HeapDumpOnOutOfMemoryError  -XX:HeapDumpPath=$CATALINA_HOME/logs/heap.dump"
    
2.并发优化
    ${tomcat}/webapps/docs/config/http.html:查看参数--->maxConnectons:最大连接数;acceptCount:队列长度(达到最大连接数时,有新连接进来,则进入队列);maxThreads:工作线程(最大请求处理线程数);minSpareThreads:最小空闲的工作线程
    
    压缩的参数不配置,配置在nginx中

3.其他优化
    ${tomcat}/webapps/docs/config/host.html:查看参数--->autoDeploy:Tomcat运行时定期检查
    ${tomcat}/webapps/docs/config/http.html:查看参数--->enableLookups:false
    ${tomcat}/webapps/docs/config/context.html:查看参数--->reloadable:false
    禁用server.xml中AJP的connector
    
    
iptables -nL  -->查看防火墙开启的端口
iptables -F   -->关闭防火墙
kill -9 进程号-->杀死进程
ps -ef|grep java-->查询java进程

    
4.APR优化(适合大并发场景):http://apr.apache.org/  -->下载apr-1.6.3.tar.gz,apr-iconv-1.2.2.tar.gz,apr-util-1.6.1.tar.gz,openssl-1.0.1s.tar.gz
        安装依赖库--->yum install apr* openssl-devel gcc make
        a.安装apr-1.6.3.tar.gz
            tar -zvxf apr-1.6.3.tar.gz
            cd apr-1.6.3
            ./configure --prefix=/usr/local/apr
            make
            make install
        b.安装apr-iconv-1.2.2.tar.gz
            tar -zvxf apr-iconv-1.2.2.tar.gz
            cd apr-iconv-1.2.2
            ./configure --prefix=/usr/local/apr-iconv --with-apr=/usr/local/apr
            make
            make install
        c.yum install expat-devel
        d.安装apr-util-1.6.1.tar.gz
            tar -zvxf apr-util-1.6.1.tar.gz
            cd apr-util-1.6.1
            ./configure --prefix=/usr/local/apr-util  --with-apr=/usr/local/apr
            make
            make install
        e.安装openssl-1.0.1s.tar.gz
            tar -zvxf openssl-1.0.1s.tar.gz
            cd openssl-1.0.1s
            ./config --prefix=/usr/local/openssl
            vi Makefile
            将原来的CFLAG=  -DOPENSSL_THREADS  -->修改为 CFLAG= -fPIC -DOPENSSL_THREADS
            make
            make install
        f.进入tomcat的bin目录
            tar -zvxf tomcat-native.tar.gz
            cd tomcat-native-1.2.17-src
            cd native
            ./configure --with-apr=/usr/local/apr  --with-ssl=/usr/local/openssl
            make
            make install
        g.修改tomcat,使用apr
            修改server.xml:
                将<Connector port="8080" protocol="HTTP/1.1" ..../>修改为protocol="org.apache.coyote.http11.Http11AprProtocol"
                <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on">--->on修改为off
                
            修改catalina.sh:
                注意->开启apr之后,jvm用到的native内存会增大,因此要适当的调大Metaspace空间,添加jvm选项:--XX:MetaspaceSize=128m
                修改为JAVA_OPTS="-server -Xms2048M -Xmx2048M --XX:MetaspaceSize=128M -XX:HeapDumpOnOutOfMemoryError  -XX:HeapDumpPath=$CATALINA_HOME/logs/heap.dump  --Djava.library.path=/usr/local/apr/lib"