recently started tomcat, the aliyun server, which has been unable to start. I studied it carefully in my spare time.
It is found that the debug port of the current application is in conflict with the debug port of other applications.

netstat -na|grep 8888

Sure enough there is a record trying to find the PID and kill it, plus the parameter showing the pid.

netstat -nap|grep 8888

The results show that.

tcp        0      0 0.0.0.0:8888                0.0.0.0:*                   LISTEN      -

1. Check the process information according to the process name, take the tomcat process name as an example, and check the corresponding process id of 1095(or use ps-aux | grep to check the memory occupation and other information of tomcat)
ps -ef | grep tomcat
2. View the process occupied port according to the process ID and view the corresponding port as 8080 (if you do not have the netstat command, install it using Yum-y Install net-tools).
netstat -nap | grep 1095
3. Check the corresponding process according to the port, and check the process ID occupying port 8080, which is 1095
netstat -tunlp | grep 8080
4. Check the process information according to the process ID, and check the process information with the process ID 1095
ps -ef | grep 1095
5. Kill the process according to the process ID. Kill the process with the process ID of 1095
kill -9 1095