常用JVM分析工具

发表于 分类于 阅读次数： 本文字数： 12k 阅读时长 ≈ 11 分钟

这篇文章是2020年在CSDN发表的，因为最近要使用其中工具，所以做文章迁移

以下工具是基于JDK11.0.5版本

命令行工具

jps

Java虚拟机进程状态工具

1
2
3
4
5
6
jps [options] [hostid]
  -q 显示进程ID
  -m 显示进程ID、主类名、传入主方法的参数
  -l 显示进程ID、全类名
  -v 显示进程ID、主类名、虚拟机参数
  -V 显示进程ID、主类名【默认】

jstat

Java虚拟机统计监控工具

1
2
3
4
5
6
7
8
9
jstat [ generalOption | outputOptions vmid [ interval [ s|ms ] [ count ] ] ]
  -generalOption通用信息，可传入-help(显示帮助信息) -version(显示版本信息[测试过，无效]) -options(显示可用的统计选项)
  -outputOptions一个或者多个输出选项，常用的如
  		-class 类加载的统计信息
  		-complier 即时编译器统计信息
  		-gc 垃圾收集器统计
  -vmid 本地虚拟机进程的话，则为对应进程ID(可通过jps查进程ID)。另外，也可以查看远程虚拟机进程
  -interval 统计的时间间隔，默认为微秒
  -count 总共统计次数

案例

~ jstat -class 1251

1
2
3
4
➜  ~ jstat -class 1251
加载的类 加载类的总大小   卸载的类     卸载类的总大小		 类加载和卸载总花费时间
Loaded  Bytes  				Unloaded  	Bytes     			Time   
  4426  8085.9      	182   			214.5       		5.79

~ jstat -gc 1251

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
➜  ~ jstat -gc 1251
 S0C    S1C    S0U    S1U      EC       EU        OC         OU       MC     MU    CCSC   CCSU   YGC     YGCT    FGC    FGCT     GCT   
 0.0    0.0    0.0    0.0   11264.0   2048.0   16384.0     7254.0   27440.0 26286.1 3200.0 2789.7      7    0.072  13      0.360    0.433
 
 各列含义：
|SOC    | 幸存区0大小(KB)|
|S1C    | 幸存区1大小(KB)|
|S0U    | 幸存区0使用大小(KB)|
|S1U    | 幸存区1使用大小(KB)|
|EC     | eden区空间大小(KB)|
|EU     | eden区空间使用大小(KB)|
|OC     | 老年代大小(KB)|
|OU     | 老年代使用大小(KB)|
|MC     | 元空间大小(KB)-1.8版本之后，用于存放方法区数据|
|MU     | 元空间使用大小(KB)|
|CCSC   | 压缩类空间大小(KB)|
|CCSU   | 压缩类空间使用大小(KB)|
|PC     | 永久区大小(KB)|
|PU     | 永久区使用大小(KB)|
|YGC    | 发生young GC次数|
|YGCT   | young GC所使用时间|
|FGC    | 发生full GC次数|
|FGCT   | full GC所使用时间|
|GCT    | 总共垃圾回收时间|

~ jstat -gcutil 1251

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
➜  ~ jstat -gcutil 1251
  S0     S1     E      O      M     CCS    YGC     YGCT    FGC    FGCT     GCT   
  0.00   0.00  27.27  44.27  95.79  87.18      7    0.072    13    0.360    0.433
  
 各列含义：
|S0     | 幸存区0使用百分比|
|S1     | 幸存区1使用百分比|
|E      | eden区使用百分比|
|O      | 老年代使用百分比|
|M      | 元空间使用百分比|
|CCS    | 压缩类空间使用百分比|
|YGC    | 发生young GC次数|
|YGCT   | young GC所使用时间|
|FGC    | 发生full GC次数|
|FGCT   | full GC所使用时间|
|GCT    | 总共垃圾回收时间|

jinfo

打印配置信息【重点其实是可以动态设置虚拟机参数】

1
2
3
jinfo [ option ] pid
  -flags 可以动态的设置或者取消或者变更JVM参数
  默认输出系统属性、JVM信息(官方目前推荐用jcmd替代jinfo，以减少影响当前进程性能)

案例

jinfo 6564(这个命令jdk1.8报各种错，暂未解决)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
➜  ~ jinfo 6564
Java System Properties:
#Mon Mar 23 23:47:56 CST 2020
gopherProxySet=false
socksProxyHost=127.0.0.1
awt.toolkit=sun.lwawt.macosx.LWCToolkit
http.proxyHost=127.0.0.1
java.specification.version=11
sun.cpu.isalist=
sun.jnu.encoding=UTF-8
java.class.path=/Users/laicreasy/github/peach/classical/target/test-classes\:/Users/laicreasy/github/peach/classical/target/classes\:/Users/laicreasy/.m2/repository/junit/junit/4.13/junit-4.13.jar\:/Users/laicreasy/.m2/repository/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar\:/Users/laicreasy/.m2/repository/org/apache/logging/log4j/log4j-api/2.13.1/log4j-api-2.13.1.jar\:/Users/laicreasy/.m2/repository/org/apache/logging/log4j/log4j-core/2.13.1/log4j-core-2.13.1.jar
https.proxyPort=8001
java.vm.vendor=Oracle Corporation
sun.arch.data.model=64
java.vendor.url=http\://java.oracle.com/
user.timezone=Asia/Shanghai
java.vm.specification.version=11
os.name=Mac OS X
sun.java.launcher=SUN_STANDARD
user.country=CN
sun.boot.library.path=/Library/Java/JavaVirtualMachines/jdk-11.0.5.jdk/Contents/Home/lib
sun.java.command=com.creasy.Concurrency
jdk.debug=release
sun.cpu.endian=little
user.home=/Users/laicreasy
user.language=en
java.specification.vendor=Oracle Corporation
java.version.date=2019-10-15
java.home=/Library/Java/JavaVirtualMachines/jdk-11.0.5.jdk/Contents/Home
file.separator=/
https.proxyHost=127.0.0.1
java.vm.compressedOopsMode=Zero based
line.separator=\n
java.specification.name=Java Platform API Specification
java.vm.specification.vendor=Oracle Corporation
java.awt.graphicsenv=sun.awt.CGraphicsEnvironment
sun.management.compiler=HotSpot 64-Bit Tiered Compilers
java.runtime.version=11.0.5+10-LTS
user.name=laicreasy
path.separator=\:
os.version=10.15.2
java.runtime.name=Java(TM) SE Runtime Environment
file.encoding=UTF-8
java.vm.name=Java HotSpot(TM) 64-Bit Server VM
java.vendor.version=18.9
java.vendor.url.bug=http\://bugreport.java.com/bugreport/
java.io.tmpdir=/var/folders/w9/1vphl83x0rz54l_x9p118n5w0000gn/T/
java.version=11.0.5
user.dir=/Users/laicreasy/github/peach/classical
os.arch=x86_64
socksProxyPort=1081
java.vm.specification.name=Java Virtual Machine Specification
java.awt.printerjob=sun.lwawt.macosx.CPrinterJob
sun.os.patch.level=unknown
java.library.path=/Users/laicreasy/Library/Java/Extensions\:/Library/Java/Extensions\:/Network/Library/Java/Extensions\:/System/Library/Java/Extensions\:/usr/lib/java\:.
java.vendor=Oracle Corporation
java.vm.info=mixed mode
java.vm.version=11.0.5+10-LTS
sun.io.unicode.encoding=UnicodeBig
java.class.version=55.0
http.proxyPort=8001

VM Flags:
-XX:CICompilerCount=3 -XX:ConcGCThreads=1 -XX:G1ConcRefinementThreads=4 -XX:G1HeapRegionSize=1048576 -XX:GCDrainStackTargetSize=64 -XX:InitialHeapSize=134217728 -XX:MarkStackSize=4194304 -XX:MaxHeapSize=2147483648 -XX:MaxNewSize=1287651328 -XX:MinHeapDeltaBytes=1048576 -XX:NonNMethodCodeHeapSize=5830732 -XX:NonProfiledCodeHeapSize=122913754 -XX:ProfiledCodeHeapSize=122913754 -XX:ReservedCodeCacheSize=251658240 -XX:+SegmentedCodeCache -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseFastUnorderedTimeStamps -XX:+UseG1GC 

VM Arguments:
jvm_args: -javaagent:/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar=49825:/Applications/IntelliJ IDEA.app/Contents/bin -Dfile.encoding=UTF-8 
java_command: com.creasy.Concurrency
java_class_path (initial): /Users/laicreasy/github/peach/classical/target/test-classes:/Users/laicreasy/github/peach/classical/target/classes:/Users/laicreasy/.m2/repository/junit/junit/4.13/junit-4.13.jar:/Users/laicreasy/.m2/repository/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar:/Users/laicreasy/.m2/repository/org/apache/logging/log4j/log4j-api/2.13.1/log4j-api-2.13.1.jar:/Users/laicreasy/.m2/repository/org/apache/logging/log4j/log4j-core/2.13.1/log4j-core-2.13.1.jar
Launcher Type: SUN_STANDARD

jmap

查看堆内存信息，可以生成dump文件

1
2
3
4
5
6
7
8
9
10
11
jmap [ option ] pid
常用如
	jmap -heap pid显示堆配置和使用情况
	jmap -clstats <pid>显示类加载器信息
    jmap -finalizerinfo <pid>打印等会finalization的对象信息
    jmap -histo[:live] <pid>堆中对象的统计，如果加上了[:live]，那么只统计当前存活的对象
    jmap -dump:<dump-options> <pid>生成堆转储快照
	    dump-options:
  	    -live        只包括当前存活的对象
    	-format=b     二进制格式
      	-file=<file>  保存的文件名

案例

~ jhsdb jmap –heap –pid 7157(jdk11下，jmap -heap pid无效)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
➜  ~ jhsdb jmap --heap --pid 7157
Attaching to process ID 7157, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 11.0.5+10-LTS

using thread-local object allocation.
Garbage-First (G1) GC with 4 thread(s)

Heap Configuration:
   MinHeapFreeRatio         = 40
   MaxHeapFreeRatio         = 70
   MaxHeapSize              = 2147483648 (2048.0MB)
   NewSize                  = 1363144 (1.2999954223632812MB)
   MaxNewSize               = 1287651328 (1228.0MB)
   OldSize                  = 5452592 (5.1999969482421875MB)
   NewRatio                 = 2
   SurvivorRatio            = 8
   MetaspaceSize            = 21807104 (20.796875MB)
   CompressedClassSpaceSize = 1073741824 (1024.0MB)
   MaxMetaspaceSize         = 17592186044415 MB
   G1HeapRegionSize         = 1048576 (1.0MB)

Heap Usage:
G1 Heap:
   regions  = 2048
   capacity = 2147483648 (2048.0MB)
   used     = 3145728 (3.0MB)
   free     = 2144337920 (2045.0MB)
   0.146484375% used
G1 Young Generation:
Eden Space:
   regions  = 4
   capacity = 15728640 (15.0MB)
   used     = 4194304 (4.0MB)
   free     = 11534336 (11.0MB)
   26.666666666666668% used
Survivor Space:
   regions  = 0
   capacity = 0 (0.0MB)
   used     = 0 (0.0MB)
   free     = 0 (0.0MB)
   0.0% used
G1 Old Generation:
   regions  = 0
   capacity = 118489088 (113.0MB)
   used     = 0 (0.0MB)
   free     = 118489088 (113.0MB)
   0.0% used

~ jmap -histo:live 7588

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
➜  ~ jmap -histo:live 7588
 num     #instances         #bytes  class name (module)
-------------------------------------------------------
   1:          7610         607736  [B (java.base@11.0.5)
   2:          7069         169656  java.lang.String (java.base@11.0.5)
   3:          1201         146592  java.lang.Class (java.base@11.0.5)
   4:          3640         116480  java.util.HashMap$Node (java.base@11.0.5)
   5:          1166          98920  [Ljava.lang.Object; (java.base@11.0.5)
   6:           379          53792  [Ljava.util.HashMap$Node; (java.base@11.0.5)
   7:            12          50104  [C (java.base@11.0.5)
   8:           332          41120  [I (java.base@11.0.5)
   9:          1232          39424  java.util.concurrent.ConcurrentHashMap$Node (java.base@11.0.5)
  10:           645          25800  java.util.LinkedHashMap$Entry (java.base@11.0.5)
  11:           392          18816  java.util.HashMap (java.base@11.0.5)
  12:            46          17440  [Ljava.util.concurrent.ConcurrentHashMap$Node; (java.base@11.0.5)
  13:           289          13792  [Ljava.lang.String; (java.base@11.0.5)
...
 511:             1             16  sun.nio.fs.NativeBuffers$1 (java.base@11.0.5)
 512:             1             16  sun.util.calendar.Gregorian (java.base@11.0.5)
 513:             1             16  sun.util.cldr.CLDRBaseLocaleDataMetaInfo (java.base@11.0.5)
 514:             1             16  sun.util.locale.InternalLocaleBuilder$CaseInsensitiveChar (java.base@11.0.5)
 515:             1             16  sun.util.locale.provider.TimeZoneNameUtility$TimeZoneNameGetter (java.base@11.0.5)
 516:             1             16  sun.util.resources.LocaleData$LocaleDataStrategy (java.base@11.0.5)
 517:             1             16  sun.util.resources.cldr.provider.CLDRLocaleDataMetaInfo (jdk.localedata@11.0.5)
Total         30567        1623664

~ jmap -dump:live,format=b,file=heap.bin 7588

1
2
➜  ~ jmap -dump:live,format=b,file=heap.bin 7588 
Heap dump file created

jhat

java堆分析工具，上述dump文件可以通过这个工具进行分析。这个工具会启动一个小型http服务器，可以通过浏览器查看分析结果。JDK11已经去掉了这个工具，直接用visual vm可视化工具分析

案例

jhat heap.bin

1
2
3
4
5
6
7
8
9
10
➜  ~ jhat heap.bin
Reading from heap.bin...
Dump file created Tue Mar 24 02:06:41 CST 2020
Snapshot read, resolving...
Resolving 30513 objects...
Chasing references, expect 6 dots......
Eliminating duplicate references......
Snapshot resolved.
Started HTTP server on port 7000
Server is ready.

打开浏览器，http://localhost:7000/ 即可看到分析信息

jstack

打印线程栈信息，如可用来分析死循环、死锁等

1
2
3
jstack [ option ] pid
	-m 打印Java和C++栈信息
	-l 额外打印关于锁的信息

案例

jstack -l 7588

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
➜  ~ jstack -l 7588
2020-03-24 02:38:42
Full thread dump Java HotSpot(TM) 64-Bit Server VM (11.0.5+10-LTS mixed mode):

Threads class SMR info:
_java_thread_list=0x00007fb213e2d690, length=11, elements={
0x00007fb215805800, 0x00007fb21404a800, 0x00007fb21483a000, 0x00007fb21404f000,
0x00007fb21501d800, 0x00007fb214064000, 0x00007fb215018000, 0x00007fb2140d3000,
0x00007fb214943000, 0x00007fb214810000, 0x00007fb214150800
}

"main" #1 prio=5 os_prio=31 cpu=314.71ms elapsed=2576.00s tid=0x00007fb215805800 nid=0x2703 runnable  [0x000070000439c000]
   java.lang.Thread.State: RUNNABLE
	at java.io.FileInputStream.readBytes(java.base@11.0.5/Native Method)
	at java.io.FileInputStream.read(java.base@11.0.5/FileInputStream.java:279)
	at java.io.BufferedInputStream.fill(java.base@11.0.5/BufferedInputStream.java:252)
	at java.io.BufferedInputStream.read(java.base@11.0.5/BufferedInputStream.java:271)
	- locked <0x00000007801261e8> (a java.io.BufferedInputStream)
	at com.creasy.Concurrency.main(Concurrency.java:24)

   Locked ownable synchronizers:
	- None

"Reference Handler" #2 daemon prio=10 os_prio=31 cpu=0.36ms elapsed=2575.95s tid=0x00007fb21404a800 nid=0x3403 waiting on condition  [0x0000700004ab1000]
   java.lang.Thread.State: RUNNABLE
	at java.lang.ref.Reference.waitForReferencePendingList(java.base@11.0.5/Native Method)
	at java.lang.ref.Reference.processPendingReferences(java.base@11.0.5/Reference.java:241)
	at java.lang.ref.Reference$ReferenceHandler.run(java.base@11.0.5/Reference.java:213)

   Locked ownable synchronizers:
	- None

"Finalizer" #3 daemon prio=8 os_prio=31 cpu=0.46ms elapsed=2575.95s tid=0x00007fb21483a000 nid=0x4903 in Object.wait()  [0x0000700004bb4000]
   java.lang.Thread.State: WAITING (on object monitor)
	at java.lang.Object.wait(java.base@11.0.5/Native Method)
	- waiting on <0x00000007801218f8> (a java.lang.ref.ReferenceQueue$Lock)
	at java.lang.ref.ReferenceQueue.remove(java.base@11.0.5/ReferenceQueue.java:155)
	- waiting to re-lock in wait() <0x00000007801218f8> (a java.lang.ref.ReferenceQueue$Lock)
	at java.lang.ref.ReferenceQueue.remove(java.base@11.0.5/ReferenceQueue.java:176)
	at java.lang.ref.Finalizer$FinalizerThread.run(java.base@11.0.5/Finalizer.java:170)

   Locked ownable synchronizers:
	- None

...

"VM Thread" os_prio=31 cpu=150.43ms elapsed=2575.96s tid=0x00007fb214002800 nid=0x4d03 runnable  

"GC Thread#0" os_prio=31 cpu=12.00ms elapsed=2575.99s tid=0x00007fb215005000 nid=0x2d03 runnable  

"GC Thread#1" os_prio=31 cpu=6.44ms elapsed=2425.77s tid=0x00007fb215896000 nid=0x4207 runnable  

"GC Thread#2" os_prio=31 cpu=8.37ms elapsed=2425.77s tid=0x00007fb214075000 nid=0x5f03 runnable  

"G1 Main Marker" os_prio=31 cpu=0.91ms elapsed=2575.99s tid=0x00007fb214022800 nid=0x5203 runnable  

"G1 Conc#0" os_prio=31 cpu=0.04ms elapsed=2575.99s tid=0x00007fb215005800 nid=0x5003 runnable  

"G1 Refine#0" os_prio=31 cpu=0.71ms elapsed=2575.99s tid=0x00007fb215836800 nid=0x3103 runnable  

"G1 Young RemSet Sampling" os_prio=31 cpu=386.00ms elapsed=2575.99s tid=0x00007fb214041800 nid=0x3203 runnable  
"VM Periodic Task Thread" os_prio=31 cpu=2000.79ms elapsed=2575.55s tid=0x00007fb214149800 nid=0x5b03 waiting on condition  

JNI global refs: 18, weak refs: 0

可视化工具

jconsole

可以监控CPU、内存、线程等情况

~jconsole

在这里插入图片描述

Visual VM

Visual VM是一款All-in-One的Java分析工具，堆栈信息、线程信息等都可以分析，而且还支持装插件。但jdk1.9之后默认JDK不再支持，可以通过https://visualvm.github.io/download.html这里下载

在1.8环境下执行

~ jvisualvm

在这里插入图片描述

reference：

相关文章