Linux Java CPU 100%

1. Find the most resource-consuming process ID with top

[bin]# Top
Top-16:56:14 up 119 days, 6:17, 7 users, load average:2.04, 2.07, 2.09
tasks:256 Total, 1 running, 254 sleeping, 0 stopped, 1 zombie
Cpu (s): 5.0%us, 0.3%sy, 0.0%ni, 94.2%id, 0.4%wa, 0.0%hi, 0.0%si, 0.0%st
mem:8303056k Total, 7368528k used, 934528k free, 515232k buffers
Swap:www.qixoo.qixoo.com 16386260k Total, 27312k used, 16358948k free, 4670096k cached

PID USER PR NI VIRT RES SHR S%cpu%MEM time+ COMMAND
5244 Root 0 1940m 1.3g 10m S 205.3 15.8 260:31.88 java
7991 Root 0 2336 1020 704 R 2.0 0.0 0:00.01 Top

2. Querying the Java processes that consume the most resources

[bin]# top-p 5244-h
top-16:56:00 up 119 days, 6:17, 7 users, Load average:2.05, 2.08, 2.09
tasks:67 Total, 2 running, sleeping, 0 stopped, 0 zombie
Cpu (s): 25.8%us, 0.2%sy, 0.0%ni, 73.4%id, 0.5%wa, 0.0%hi, 0.1%si, 0.0%st
mem:8303056k Total, 7369024k used, 934032k free, 515220k buffers
swap:16386260k Total, 27312k used, 16358948k free, 4670100k cached

PID USER PR NI VIRT RES SHR S%cpu%MEM time+ COMMAND
5920 Root 0 1940m 1.3g 10m R 98.6 15.8 121:55.29 java
5925 Root 0 1940m 1.3g 10m R 98.6 15.8 121:21.41 java
7985 Root 0 1940m 1.3g 10m S 3.3 15.8 0:00.10 java
5246 Root 0 1940m 1.3g 10m S 1.0 15.8 1:02.50 Java
5247 Root 0 1940m 1.3g 10m S 1.0 15.8 1:02.35 Java
5248 Root 0 1940m 1.3g 10m S 1.0 15.8 1:02.38 Java

3. Print Java stack information

Execute under the bin of the JDK

[bin]# jstack 5244 >stack.txt

4. Convert the javapid of the cost source to 16 binary (5920 ext. 1720 to Baidu: Decimal to hex)

The PID corresponds to nid (16 binary) in the stack

To find the nid=1720 problem in Stack.txt

"Longtimetask Thread" daemon prio=10 tid=0x40916400 nid=0x1720 runnable [0x412fe000]
Java.lang.Thread.State:RUNNABLE
At Com.zving.tk.service.CreatePaperService.createPaper (createpaperservice.java:143)
At Com.zving.tk.service.CreatePaperService.execute (createpaperservice.java:55)
At Com.zving.framework.messages.LongTimeTask.run (longtimetask.java:154)

5. Find source code based on specific issues

6. Also take a look at the heap

Execution in the bin directory of the JDK

Jmap-heap 5244

Jmap-histo 5244

Linux Java CPU 100%