@[TOC]
[root@localhost ~]# jps -lvm
7457 org.apache.catalina.startup.Bootstrap start start -Djava.util.logging.config.file=/application/tomcat/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= -Dcatalina.base=/application/tomcat -Dcatalina.home=/application/tomcat -Djava.io.tmpdir=/application/tomcat/temp
7525 org.apache.catalina.startup.Bootstrap start start -Djava.util.logging.config.file=/application/tomcat_8082/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= -Dcatalina.base=/application/tomcat_8082 -Dcatalina.home=/application/tomcat_8082 -Djava.io.tmpdir=/application/tomcat_8082/temp
9144 sun.tools.jps.Jps -lvm -Denv.class.path=.:/application/jdk/lib:/application/jdk/jre/lib:/application/jdk/lib/tools.jar -Dapplication.home=/application/jdk1.8.0_60 -Xms8m
7482 org.apache.catalina.startup.Bootstrap start start -Djava.util.logging.config.file=/application/tomcat_8081/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= -Dcatalina.base=/application/tomcat_8081 -Dcatalina.home=/application/tomcat_8081 -Djava.io.tmpdir=/application/tomcat_8081/temp
[root@localhost ~]# jmap -heap 7457
Attaching to process ID 7457, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.60-b23
using thread-local object allocation.
Mark Sweep Compact GC
Heap Configuration:
MinHeapFreeRatio = 40
MaxHeapFreeRatio = 70
MaxHeapSize = 255852544 (244.0MB)
NewSize = 5570560 (5.3125MB)
MaxNewSize = 85262336 (81.3125MB)
OldSize = 11206656 (10.6875MB)
NewRatio = 2
SurvivorRatio = 8
MetaspaceSize = 21807104 (20.796875MB)
CompressedClassSpaceSize = 1073741824 (1024.0MB)
MaxMetaspaceSize = 17592186044415 MB
G1HeapRegionSize = 0 (0.0MB)
Heap Usage: #监控的话关注这一列
New Generation (Eden + 1 Survivor Space):
capacity = 12779520 (12.1875MB)
used = 11689352 (11.147834777832031MB)
free = 1090168 (1.0396652221679688MB)
91.46941356169872% used
Eden Space: #监控的话关注这一列
capacity = 11403264 (10.875MB)
used = 11059616 (10.547271728515625MB)
free = 343648 (0.327728271484375MB)
96.98640669899426% used
From Space: #监控的话关注这一列
capacity = 1376256 (1.3125MB)
used = 629736 (0.6005630493164062MB)
free = 746520 (0.7119369506835938MB)
45.75718470982143% used
To Space: #监控的话关注这一列
capacity = 1376256 (1.3125MB)
used = 0 (0.0MB)
free = 1376256 (1.3125MB)
0.0% used
tenured generation: #监控的话关注这一列
capacity = 28164096 (26.859375MB)
used = 18313224 (17.46485137939453MB)
free = 9850872 (9.394523620605469MB)
65.02329774760035% used
21146 interned Strings occupying 1882520 bytes.
[root@localhost ~]# jstack -l 7457
系统负载高,tomcat 占用 CPU 较高
#修改bin/catalina.sh
[root@localhost tomcat]# vim bin/catalina.sh
#注意不能分行写会报错找不到命令,要写在一行上
CATALINA_OPTS="$CATALINA_OPTS"
-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=12345
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jxmremote.ssl=false
-Djava.rmi.server.hostname="192.168.81.210"
#正确写法
CATALINA_OPTS="$CATALINA_OPTS -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=12345 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jxmremote.ssl=false -Djava.rmi.server.hostname=192.168.81.210"
#说明
CATALINA_OPTS="$CATALINA_OPTS" #修改tomcat启动参数
-Dcom.sun.management.jmxremote #开启tomcat远程管理功能
-Dcom.sun.management.jmxremote.port=12345 #远程管理功能,除了12345端口,还会生成2个随机端口,我们可以开放所有端口
Dcom.sun.management.jmxremote.authenticat=false #是否在监控时需要认证
-Dcom.sun.management.jmxremote.ssl=false #是否开启ssl连接
-Djava.rmi.server.hostname="192.168.81.210" #设置tomcat所在服务器的ip
配置完成后重启tomcat即可
使用ps命令可以看到输出的信息多了我们写入的几行
[root@localhost tomcat]# ps aux | grep java
root 17786 5.7 10.6 2306592 105860 pts/1 Sl 15:52 0:08 /application/jdk/bin/java
-Djava.util.logging.config.file=/application/tomcat/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
-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=12345
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jxmremote.ssl=false
-Djava.rmi.server.hostname=192.168.81.210
-Dignore.endorsed.dirs=
-classpath /application/tomcat/bin/bootstrap.jar:/application/tomcat/bin/tomcat-juli.jar
-Dcatalina.base=/application/tomcat
-Dcatalina.home=/application/tomcat
-Djava.io.tmpdir=/application/tomcat/temp org.apache.catalina.startup.Bootstrap start
使用ss/netstat 命令可以看到多出啦的三个端口
[root@localhost tomcat]# ss -lnptu | grep java
tcp LISTEN 0 100 :::8080 :::* users:(("java",pid=17786,fd=56))
#我们制定的
tcp LISTEN 0 50 :::12345 :::* users:(("java",pid=17786,fd=22))
#随机的1
tcp LISTEN 0 50 :::46272 :::* users:(("java",pid=17786,fd=21))
#随机的2
tcp LISTEN 0 50 :::46081 :::* users:(("java",pid=17786,fd=24))
tcp LISTEN 0 1 ::ffff:127.0.0.1:8005 :::* users:(("java",pid=17786,fd=65))
领取专属 10元无门槛券
私享最新 技术干货