Java 分析工具汇总
http://blog.csdn.net/fenglibing/article/details/6411999
jps
jps -mlvV
jmap -heap <pid> 查看jvm内存设置和使用情况
[root@datanode169 ~]# jmap -heap 29090 Attaching to process ID 29090, please wait... Debugger attached successfully. Server compiler detected. JVM version is 24.76-b04 using thread-local object allocation. Parallel GC with 8 thread(s) Heap Configuration: MinHeapFreeRatio = 0 MaxHeapFreeRatio = 100 MaxHeapSize = 402653184 (384.0MB) NewSize = 1310720 (1.25MB) MaxNewSize = 17592186044415 MB OldSize = 5439488 (5.1875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 268435456 (256.0MB) MaxPermSize = 268435456 (256.0MB) G1HeapRegionSize = 0 (0.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 66060288 (63.0MB) used = 50225360 (47.89863586425781MB) free = 15834928 (15.101364135742188MB) 76.02958073691717% used From Space: capacity = 5242880 (5.0MB) used = 5235920 (4.9933624267578125MB) free = 6960 (0.0066375732421875MB) 99.86724853515625% used To Space: capacity = 5242880 (5.0MB) used = 0 (0.0MB) free = 5242880 (5.0MB) 0.0% used PS Old Generation capacity = 85983232 (82.0MB) used = 22836088 (21.77819061279297MB) free = 63147144 (60.22180938720703MB) 26.558769039991425% used PS Perm Generation capacity = 268435456 (256.0MB) used = 12044040 (11.486091613769531MB) free = 256391416 (244.51390838623047MB) 4.486754536628723% used 4893 interned Strings occupying 424080 bytes. [root@datanode169 ~]#
jmap -histo <pid>
jmap -dump:live,format=b,file=szc.dump <pid>
利用top 和 jstack 分析
// 以线程3301 为例
# top -n 1 -Hp 3301
Tasks: 35 total, 0 running, 35 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.6%us, 0.2%sy, 0.0%ni, 98.1%id, 1.1%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 8076704k total, 7929456k used, 147248k free, 117748k buffers
Swap: 8190972k total, 17328k used, 8173644k free, 2669008k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3318 root 20 0 3312m 192m 10m S 2.0 2.4 0:02.24 java
3301 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3302 root 20 0 3312m 192m 10m S 0.0 2.4 0:01.93 java
3303 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.03 java
3304 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.02 java
3305 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3306 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.02 java
3307 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3308 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.02 java
3309 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3310 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.02 java
3311 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.12 java
3312 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3313 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3314 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3315 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.34 java
3316 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.36 java
3317 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3319 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.03 java
3329 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3330 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3353 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3432 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3433 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.02 java
3434 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.02 java
3435 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.01 java
3436 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3437 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3438 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3439 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3440 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3441 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
3442 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.04 java
3443 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.05 java
6106 root 20 0 3312m 192m 10m S 0.0 2.4 0:00.00 java
# jstack -l 3301
// 截取部分输出如下
"Thread-6" prio=10 tid=0x00007f1ee05d1800 nid=0xd68 waiting on condition [0x00007f1ecafc4000]
java.lang.Thread.State: TIMED_WAITING (sleeping)
at java.lang.Thread.sleep(Native Method)
可以看出 0xd68 是 3432 的16进制
1. 不同的 JAVA虚机的线程 DUMP的创建方法和文件格式是不一样的，不同的 JVM版本， dump信息也有差别。本文中，只以 SUN的 hotspot JVM 5.0_06 为例。
2. 在实际运行中，往往一次 dump的信息，还不足以确认问题。建议产生三次 dump信息，如果每次 dump都指向同一个问题，我们才确定问题的典型性。
参考 http://josh-persistence.iteye.com/blog/2161848?utm_source=tuicool&utm_medium=referral
