java占用CPU分析

2019-08-02 本文已影响0人 Al_不期而遇

找到对应进程的PID

[root@master1 rundeck]# top

top - 03:10:32 up 8:06, 2 users, load average: 0.08, 0.03, 0.05

Tasks: 243 total, 2 running, 241 sleeping, 0 stopped, 0 zombie

%Cpu(s): 0.1 us, 0.1 sy, 0.0 ni, 99.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st

KiB Mem : 3874956 total, 383964 free, 1264232 used, 2226760 buff/cache

KiB Swap: 4063228 total, 4063228 free, 0 used. 2329668 avail Mem

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

25136 root 20 0 4769720 940148 16168 S 0.6 24.3 3:56.49 java

25389 root 20 0 148200 2128 1420 R 0.6 0.1 0:00.07 top

1 root 20 0 43388 3644 2352 S 0.0 0.1 0:04.88 systemd

2 root 20 0 0 0 0 S 0.0 0.0 0:00.03 kthreadd

3 root 20 0 0 0 0 S 0.0 0.0 0:03.43 ksoftirqd/0

5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H

7 root rt 0 0 0 0 S 0.0 0.0 0:00.14 migration/0

8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh

9 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/0

10 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/1

11 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/2

12 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/3

13 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/4

显示线程列表，同时按照CPU占用高的线程排序

[root@master1 rundeck]# ps -mp 25136 -o THREAD,tid,time |sort -rn

USER %CPU PRI SCNT WCHAN USER SYSTEM TID TIME

root 5.9 - - - - - - 00:03:56

root 1.5 19 - futex_ - - 25148 00:01:01

root 1.5 19 - futex_ - - 25147 00:01:01

root 1.5 19 - futex_ - - 25138 00:01:01

root 0.2 19 - futex_ - - 25151 00:00:08

root 0.2 19 - futex_ - - 25149 00:00:11

root 0.0 19 - inet_c - - 25166 00:00:00

root 0.0 19 - futex_ - - 25195 00:00:00

root 0.0 19 - futex_ - - 25194 00:00:00

root 0.0 19 - futex_ - - 25193 00:00:00

root 0.0 19 - futex_ - - 25188 00:00:00

root 0.0 19 - futex_ - - 25187 00:00:01

root 0.0 19 - futex_ - - 25186 00:00:01

root 0.0 19 - futex_ - - 25185 00:00:01

root 0.0 19 - futex_ - - 25184 00:00:00

root 0.0 19 - futex_ - - 25183 00:00:00

root 0.0 19 - futex_ - - 25182 00:00:00

root 0.0 19 - futex_ - - 25181 00:00:01

root 0.0 19 - futex_ - - 25180 00:00:00

root 0.0 19 - futex_ - - 25179 00:00:00

root 0.0 19 - futex_ - - 25178 00:00:01

root 0.0 19 - futex_ - - 25177 00:00:00

root 0.0 19 - futex_ - - 25176 00:00:00

root 0.0 19 - futex_ - - 25175 00:00:00

root 0.0 19 - futex_ - - 25174 00:00:00

root 0.0 19 - futex_ - - 25173 00:00:00

root 0.0 19 - futex_ - - 25172 00:00:00

root 0.0 19 - futex_ - - 25171 00:00:00

root 0.0 19 - futex_ - - 25170 00:00:03

root 0.0 19 - futex_ - - 25168 00:00:00

root 0.0 19 - futex_ - - 25165 00:00:00

root 0.0 19 - futex_ - - 25163 00:00:00

root 0.0 19 - futex_ - - 25162 00:00:00

root 0.0 19 - futex_ - - 25161 00:00:00

root 0.0 19 - futex_ - - 25160 00:00:00

root 0.0 19 - futex_ - - 25158 00:00:00

root 0.0 19 - futex_ - - 25155 00:00:00

root 0.0 19 - futex_ - - 25154 00:00:01

root 0.0 19 - futex_ - - 25150 00:00:00

root 0.0 19 - futex_ - - 25146 00:00:00

root 0.0 19 - futex_ - - 25145 00:00:00

root 0.0 19 - futex_ - - 25144 00:00:00

root 0.0 19 - futex_ - - 25143 00:00:01

root 0.0 19 - futex_ - - 25142 00:00:03

root 0.0 19 - futex_ - - 25141 00:00:03

root 0.0 19 - futex_ - - 25140 00:00:03

root 0.0 19 - futex_ - - 25139 00:00:03

root 0.0 19 - futex_ - - 25136 00:00:00

root 0.0 19 - ep_pol - - 25167 00:00:00

root 0.0 19 - ep_pol - - 25164 00:00:00

将线程的PID转换为16进制

[root@master1 rundeck]# printf "%x\n" 25148

623c

使用jstack打印该进程下面的此线程的堆栈信息

[root@master1 rundeck]# jstack 25136 | grep "623c" -A 30

"C2 CompilerThread1" #6 daemon prio=9 os_prio=0 tid=0x00007ff4a41e6800 nid=0x623c waiting on condition [0x0000000000000000]

java.lang.Thread.State: RUNNABLE

"C2 CompilerThread0" #5 daemon prio=9 os_prio=0 tid=0x00007ff4a41d7000 nid=0x623b waiting on condition [0x0000000000000000]

java.lang.Thread.State: RUNNABLE

"Signal Dispatcher" #4 daemon prio=9 os_prio=0 tid=0x00007ff4a41d5000 nid=0x623a runnable [0x0000000000000000]

java.lang.Thread.State: RUNNABLE

"Finalizer" #3 daemon prio=8 os_prio=0 tid=0x00007ff4a41ab000 nid=0x6239 in Object.wait() [0x00007ff4941f0000]

java.lang.Thread.State: WAITING (on object monitor)

at java.lang.Object.wait(Native Method)

at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)

- locked <0x00000000c000d3d8> (a java.lang.ref.ReferenceQueue$Lock)

at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:165)

at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:216)

"Reference Handler" #2 daemon prio=10 os_prio=0 tid=0x00007ff4a41a6000 nid=0x6238 in Object.wait() [0x00007ff4942f1000]

java.lang.Thread.State: WAITING (on object monitor)

at java.lang.Object.wait(Native Method)

at java.lang.Object.wait(Object.java:502)

at java.lang.ref.Reference.tryHandlePending(Reference.java:191)

- locked <0x00000000c000d590> (a java.lang.ref.Reference$Lock)

at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)

"VM Thread" os_prio=0 tid=0x00007ff4a419c800 nid=0x6237 runnable

"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00007ff4a405e000 nid=0x6233 runnable

"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00007ff4a4060000 nid=0x6234 runnable

打印GC 信息

[root@master1 rundeck]# jstat -gcutil 25136 200 50

S0 S1 E O M CCS YGC YGCT FGC FGCT GCT

52.90 0.00 18.26 60.04 96.67 91.29 60 2.571 4 2.037 4.608

导出内存快照

[root@master1 rundeck]# jmap -dump:live,format=b,file=dump.hprof 25136

Dumping heap to /home/rundeck/rundeck/dump.hprof ...

Heap dump file created

寻找合适的工具分析内存。

java占用CPU分析

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