JAVA进程CPU占用率分析方法
1:? 首先把JDK Linux版本上传到服务器上.
2:? 使用命令 jstack PID 命令打印出CPU占用过高进程的线程栈.
3: 使用top -H -p PID 命令查看对应进程是哪个线程占用CPU过高. 比如:
top - 17:23:50 up 12 days,? 1:44,? 8 users,? load average: 4.85, 3.56, 3.76
Tasks: 556 total,?? 1 running, 555 sleeping,?? 0 stopped,?? 0 zombie
Cpu(s):? 7.4%us,? 4.4%sy,? 0.4%ni, 71.6%id, 15.5%wa,? 0.0%hi,? 0.6%si,? 0.0%st
Mem:???? 32072M total,??? 31972M used,????? 100M free,????? 265M buffers
Swap:???? 2047M total,?????? 81M used,???? 1965M free,??? 23734M cached
? PID USER????? PR? NI? VIRT? RES? SHR S %CPU %MEM??? TIME+? COMMAND
17363 webserve? 20?? 0 4475m 2.9g? 10m R?? 54? 9.4 163:29.84 java
16452 webserve? 20?? 0 4475m 2.9g? 10m S??? 6? 9.4?? 6:03.00 java
11283 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.35 java
11284 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.41 java
11285 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:20.89 java
11288 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.18 java
11291 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.04 java
11280 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:20.66 java
11281 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.41 java
11282 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.26 java
11286 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.36 java
11287 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.43 java
11289 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.80 java
11290 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:22.13 java
11292 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4?? 7:21.35 java
11293 webserve? 20?? 0 4475m 2.9g? 10m S??? 2? 9.4? 24:29.70 java
18727 webserve? 20?? 0 4475m 2.9g? 10m S??? 1? 9.4?? 3:08.50 java
18812 webserve? 20?? 0 4475m 2.9g? 10m S??? 1? 9.4?? 3:05.80 java
18829 webserve? 20?? 0 4475m 2.9g? 10m S??? 1? 9.4?? 3:03.32 java
19888 webserve? 20?? 0 4475m 2.9g? 10m S??? 1? 9.4?? 3:04.66 java
比如上面信息就可以看到 17363 线程CPU使用较高, 把这个值转换为 16 进制, 然后在第2步打印的
线程栈中进行搜索, 就可以知道这个线程栈是做什么的了.
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1 top??
得到最高的pid
2? 查看pid子进程
top -H -p PID
3 查看子进程的详情
./jstack -F? pid
