运维-JVM监控之线程问题

jstack主要用来查看某个Java进程内的线程堆栈信息

1、ps -ef |grep 应用名称 --获取pid

2、top -Hp pid --找出该进程内最耗费CPU的线程

例：top -Hp 31385

 PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND                                                                                                

31499 admin     20   0 3795904 591760  14224 S  0.3  3.7   1:12.22 java                                                                                                   

31385 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:00.00 java                                                                                                   

31388 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:19.00 java                                                                                                   

31389 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:01.29 java                                                                                                   

31390 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:01.31 java                                                                                                   

31391 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:02.11 java                                                                                                   

31392 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:00.02 java                                                                                                   

31393 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:00.04 java                                                                                                   

31394 admin     20   0 3795904 591760  14224 S  0.0  3.7   0:00.00 java                                                                                                   

31395 admin     20   0 3795904 591760  14224 S  0.0  3.7   1:09.64 java

TIME列就是各个Java线程耗费的CPU时间。

3、printf "%x\n" 线程id --将线程id转化为十六进制

例：printf "%x\n" 31499

       7b0b

4、jstack pid | grep 十六进制线程id --查询堆栈信息

例：jstack 31385|grep 7b0b
"MQ-AsyncArrayDispatcher-Thread-31385#-1244857759#-1596142409#9048915282620395" #72 daemon prio=5 os_prio=0 tid=0x00007f6c058ea800 nid=0x7b0b in Object.wait()  [0x00007f6be22a1000]

定位：线程名为MQ-AsyncArrayDispatcher-.....，wait()方法。