CentOS7下配置Tomcat以APR模式+Tomcat Native运行

　　在慢速网络上Tomcat线程数开到300以上的水平，不配APR，基本上300个线程狠快就会用满，以后的请求就只好等待。但是配上APR之后，Tomcat将以JNI的形式调用Apache HTTP服务器的核心动态链接库来处理文件读取或网络传输操作，这时并发的线程数量明显下降，从原来的300可能会马上下降到只有几十，新的请求会毫无阻塞的进来。

　　Tomcat 可以使用 apr 来提供更好的伸缩性、性能和集成到本地服务器技术，用来提高 tomcat 的性能。而tomcat native在具体的运行平台上提供了一种优化技术，它本身是基于 ARP（Apache Portable（轻便） Runtime）技术。在我们应用了tomcat native后，tomcat在跟操作系统级别的交互方面可以做得更好，并且它更像apache一样，可以更好地作为一台 web server。tomcat 可以利用apache的apr接口，使用操作系统的部分本地操作，从而提升性能APR 提升的是静态页面处理能力。

(1).Tomcat的三种运行模式介绍

　　Tomcat 有三种 运行模式，bio、nio、apr。

　　bio(blocking I/O)，阻塞式I/O操作，表示Tomcat使用的是传统的Java I/O操作(即java.io包及其子包)，对于每一个请求都要创建一个线程来进行处理，所以开销较大不适合处理高并发的场景。Tomcat在默认情况下，就是以bio模式运行的。遗憾的是，就一般而言，bio模式是三种运行模式中性能最低的一种。我们可以通过Tomcat Manager来查看服务器的当前状态。

　　nio是Java SE 1.4及后续版本提供的一种新的I/O操作方式(即java.nio包及其子包)，基于缓冲区、并能提供非阻塞I/O操作的Java API实现，比传统的I/O处理方式（bio）有更高的并发运行性能。是Tomcat8的默认运行模式。

　　apr(Apache Portable Runtime/Apache可移植运行库)是Apache HTTP服务器的支持库。从操作系统级别解决异步I/O问题，大幅度提高服务器的并发处理性能，也是Tomcat生产环境运行的首选方式。要tomcat支持apr，必须安装apr和native，这样tomcat才可以利用apache的apr接口，使用操作系统的部分本地操作，从而提升性能。

(2).安装Tomcat Native

　　注意：Tomcat Native已经集成到Tomcat8安装目录下的bin目录。

　1）安装依赖包

　　注意：这里有个apr-devel，作为依赖apr也会被安装。

[root@youxi1 ~]# yum -y install apr-devel gcc gcc-c++ openssl-devel openssl　　

　2）解压Tomcat Native包，编译安装

[root@youxi1 ~]# tar zxf /usr/local/tomcat8.5/bin/tomcat-native.tar.gz -C /usr/local/src/
[root@youxi1 ~]# cd /usr/local/src/tomcat-native-1.2.18-src/native/
[root@youxi1 native]# ./configure --with-apr=/usr/ --with-java-home=/usr/local/jdk1.8.0_191 --with-ssl
[root@youxi1 native]# make && make install　　//编译安装
----------------------------------------------------------------------
Libraries have been installed in:　　//库安装在如下地址
/usr/local/apr/lib

If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the `-LLIBDIR'
flag during linking and do at least one of the following:
- add LIBDIR to the `LD_LIBRARY_PATH' environment variable
during execution
- add LIBDIR to the `LD_RUN_PATH' environment variable
during linking
- use the `-Wl,-rpath -Wl,LIBDIR' linker flag
- have your system administrator add LIBDIR to `/etc/ld.so.conf'

See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
----------------------------------------------------------------------
[root@youxi1 native]# echo $?
0

　　说明：./configure有两个参数需要注意下，--with-apr=/usr/提供的是查找apr的路径可以更详细的一点，--with-java-home后面跟随的地址要和"echo $JAVA_HOME"输出地址一致。

　3）根据安装完成后的提示操作

　　把库添加到/etc/ld.so.conf

[root@youxi1 native]# vim /etc/ld.so.conf
/usr/local/apr/lib    //添加该行
[root@youxi1 native]# ldconfig　　//重新加载
[root@youxi1 native]# echo "ldconfig" >> /etc/rc.local　　//这是开机自启文件的软链接，需要源文件有执行权限
[root@youxi1 native]# ll /etc/rc.local
lrwxrwxrwx. 1 root root 13 5月 14 09:12 /etc/rc.local -> rc.d/rc.local

　　配置环境变量

[root@youxi1 native]# vim /etc/profile.d/jdk8.sh　　//这是之前的JDK环境变量文件
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/apr/lib　　//新增一行
[root@youxi1 native]# . /etc/profile.d/jdk8.sh　　//刷新

(3).配置APR

　1）修改conf/server.xml里的协议

　　这个协议是<service>标签里的<Connector>标签的参数protocol，默认协议是HTTP/1.1。我们将协议修改为org.apache.coyote.http11.Http11AprProtocol

[root@youxi1 native]# vim /usr/local/tomcat8.5/conf/server.xml
<Connector port="8080" protocol="org.apache.coyote.http11.Http11AprProtocol"　　//将HTTP/1.1修改为当前值
connectionTimeout="20000"
redirectPort="8443" />

　2）在bin/catalina.sh中引用apr

[root@youxi1 native]# vim /usr/local/tomcat8.5/bin/catalina.sh
# Register custom URL handlers
# Do this here so custom URL handles (specifically 'war:...') can be used in the
 security policy
JAVA_OPTS="$JAVA_OPTS -Djava.protocol.handler.pkgs=org.apache.catalina.webresour
ces"　　//这是第253行，在这下面添加一行参数
JAVA_OPTS="$JAVA_OPTS -Djava.library.path=/usr/local/apr/lib"　　//只要添加这一行

　　注意：只要添加一行。

　3）重启Tomcat

[root@youxi1 native]# ps aux | grep /usr/local/tomcat8.5/
root       1113  0.6 11.9 2327404 119308 ?      Sl   17:15   0:31 /usr/local/jdk1.8.0_191/bin/java -Djava.util.logging.config.file=/usr/local/tomcat8.5/conf/logging.properties
 -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources
 -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 -Dignore.endorsed.dirs= -classpath /usr/local/tomcat8.5/bin/bootstrap.jar:/usr/local/tomcat8.5/bin/tomcat-juli.jar
 -Dcatalina.base=/usr/local/tomcat8.5 -Dcatalina.home=/usr/local/tomcat8.5 -Djava.io.tmpdir=/usr/local/tomcat8.5/temp org.apache.catalina.startup.Bootstrap start
root       3078  0.0  0.1 112728  1004 pts/0    R+   18:30   0:00 grep --color=auto /usr/local/tomcat8.5/
[root@youxi1 native]# kill -9 1113
[root@youxi1 native]# !ps
ps aux | grep /usr/local/tomcat8.5/
root       3081  0.0  0.1 112728  1000 pts/0    R+   18:30   0:00 grep --color=auto /usr/local/tomcat8.5/
[root@youxi1 native]# /usr/local/tomcat8.5/bin/startup.sh
Using CATALINA_BASE:   /usr/local/tomcat8.5
Using CATALINA_HOME:   /usr/local/tomcat8.5
Using CATALINA_TMPDIR: /usr/local/tomcat8.5/temp
Using JRE_HOME:        /usr/local/jdk1.8.0_191
Using CLASSPATH:       /usr/local/tomcat8.5/bin/bootstrap.jar:/usr/local/tomcat8.5/bin/tomcat-juli.jar
Tomcat started.
[root@youxi1 native]# !ps
ps aux | grep /usr/local/tomcat8.5/
root       3091 94.6  7.2 2302932 72308 pts/0   Sl   18:31   0:04 /usr/local/jdk1.8.0_191/bin/java -Djava.util.logging.config.file=/usr/local/tomcat8.5/conf/logging.properties
 -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources
 -Djava.library.path=/usr/local/apr/lib -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 -Dignore.endorsed.dirs= -classpath /usr/local/tomcat8.5/bin/bootstrap.jar:/usr/local/tomcat8.5/bin/tomcat-juli.jar
 -Dcatalina.base=/usr/local/tomcat8.5 -Dcatalina.home=/usr/local/tomcat8.5 -Djava.io.tmpdir=/usr/local/tomcat8.5/temp org.apache.catalina.startup.Bootstrap start
root       3108  0.0  0.1 112728  1004 pts/0    R+   18:31   0:00 grep --color=auto /usr/local/tomcat8.5/

　4）查看日志是否支持native

[root@youxi1 ~]# cat /usr/local/tomcat8.5/logs/catalina.out | grep Native 
29-Jun-2019 17:47:25.635 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
29-Jun-2019 18:17:01.395 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
29-Jun-2019 18:24:08.267 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 09:40:11.168 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 11:45:02.398 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 11:45:24.769 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 11:54:19.711 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 11:59:23.422 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 12:11:33.778 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 12:32:55.610 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 14:33:56.449 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 17:15:19.203 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib]
30-Jun-2019 18:31:10.739 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent Loaded APR based Apache Tomcat Native library [1.2.18] using APR version [1.4.8].

　　看最后一行，只有出现这一行才代表成功了。

参考：https://www.cnblogs.com/zishengY/p/7101616.html?utm_source=itdadao&utm_medium=referral

　　　https://www.cnblogs.com/hackyo/p/6792349.html

　　　https://www.cnblogs.com/passedbylove/p/7489425.html