jvm 命令

作者: 程序男保姆 | 来源:发表于2020-06-07 12:43 被阅读0次

JVM性能监控工具使用说明
JVM - 调优命令
jvm调优常用命令
JVM命令与调试工具
阿尔萨斯-jvm
JVM | 命令行工具
jvm系列(四):jvm调优-命令大全（jps jstat jm
jvm常用：命令、参数
jvm监控与调优之jdk命令行工具
Linux使用jstat命令查看jvm的GC情况

jps 虚拟机进程状况工具

查看虚拟机进程
jps 

24849 Jps
24119 JvmDemoApplication

查看虚拟机进程 有类路径
jps -l
24119 com.example.JvmDemoApplication
24888 sun.tools.jps.Jps

查看虚拟机进程 jvm启动参数
jps -v 

24119 JvmDemoApplication -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:52597,suspend=y,server=n -XX:TieredStopAtLevel=1 -Xverify:none -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true -javaagent:/Users/baidu/Library/Caches/IntelliJIdea2019.2/captureAgent/debugger-agent.jar -Dfile.encoding=UTF-8

查看虚拟机进程 省略主类名称
jps -q

22640
22560
24962
22581
24118
22550
24119
23420

查看虚拟机进程 传递给main 函数的参数
jps -m 

24119 JvmDemoApplication

查看虚拟机进程 过滤

jps -m | grep JvmDemoApplication

jstat 虚拟机统计信息监控工具

每1秒执行一次 执行10次
jstat -gcutil 22442 1000 10


监视类装载 卸载数量 总空间以及类装载所耗费的时间
jstat -class 19852

Loaded  Bytes  Unloaded  Bytes     Time   
  6284 11417.7        0     0.0       5.14

监视Java堆状况，包括eden区 两个survivor 老年代 永久代 已用空间 gc时间
jstat -gc 19852

 S0C    S1C    S0U    S1U      EC       EU        OC         OU       MC     MU    CCSC   CCSU   YGC     YGCT    FGC    FGCT     GCT   
1024.0 1024.0  0.0   480.7   8256.0   1311.1   20480.0    11421.2   34048.0 32236.6 4608.0 4178.4     49    0.199   1      0.051    0.250


与-gc相同 但输出内容为使用总空间占比
jstat -gcutil 22442

  S0     S1     E      O      M     CCS    YGC     YGCT    FGC    FGCT     GCT   
 58.57   0.00  35.79  51.70  94.45  91.94     46    0.190     1    0.029    0.218

与-gcutil 相同 但是会额外输出上次gc发生的原因
jstat -gccause 22442
  S0     S1     E      O      M     CCS    YGC     YGCT    FGC    FGCT     GCT    LGCC                 GCC                 
  0.00  76.81  34.42  52.46  94.77  92.37     47    0.196     1    0.029    0.225 Allocation Failure   No GC               


监视新生代
jstat -gcnew 22442

 S0C    S1C    S0U    S1U   TT MTT  DSS      EC       EU     YGC     YGCT  
1024.0 1024.0  599.7    0.0  2  15  512.0   8256.0   3120.4     46    0.190

监视新生代 最大使用情况
jstat -gcnew 22442

NGCMN      NGCMX       NGC      S0CMX     S0C     S1CMX     S1C       ECMX        EC      YGC   FGC 
10240.0   156992.0    10304.0  15680.0   1024.0  15680.0   1024.0   125632.0     8256.0    47     1

jinfo java 配置信息工具

 查看是否使用类 serial gc收集器
 jinfo -flag UseSerialGC 24902 

 -XX:-UseSerialGC


查看全部信息
 jinfo -flags 24902

Attaching to process ID 24902, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.181-b13
Non-default VM flags: -XX:CICompilerCount=2 -XX:InitialHeapSize=31457280 -XX:MaxHeapSize=482344960 -XX:MaxNewSize=160759808 -XX:MinHeapDeltaBytes=196608 -XX:NewSize=10485760 -XX:OldSize=20971520 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops 
Command line:

jmap java 内存映射工具

手动执行gc
jmap -histo:live pid

jmap -dump:live,file=dump_001.bin PID 
然后删掉dump_001.bin文件

 导出堆信息到文件b 格式为byte
 jmap -dump:format=b,file=/root/b.bin 28806

Dumping heap to /root/b1.bin ...
Heap dump file created

显示堆中对象统计信息

jmap -histo 2483

pid                类数量     实例数   
2483:             1             16  sun.reflect.generics.tree.VoidDescriptor
2484:             1             16  sun.security.provider.NativePRNG
2485:             1             16  sun.security.util.AlgorithmDecomposer
2486:             1             16  sun.security.util.DisabledAlgorithmConstraints$Constraints
2487:             1             16  sun.util.calendar.Gregorian
2488:             1             16  sun.util.locale.provider.AuxLocaleProviderAdapter$NullProvider
2489:             1             16  sun.util.locale.provider.CalendarDataUtility$CalendarWeekParameterGetter
2490:             1             16  sun.util.locale.provider.SPILocaleProviderAdapter
2491:             1             16  sun.util.locale.provider.TimeZoneNameUtility$TimeZoneNameGetter
2492:             1             16  sun.util.resources.LocaleData
2493:             1             16  sun.util.resources.LocaleData$LocaleDataResourceBundleControl
Total        251635       14990856
 

查看堆详细信息 具体回收器 参数配置 分代状况
（jstat -gc pid ,jstat -gcutil pid 打印简略信息）
 jmap -heap 28806

Attaching to process ID 28806, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.181-b13

using thread-local object allocation.
Mark Sweep Compact GC

Heap Configuration:
   MinHeapFreeRatio         = 40
   MaxHeapFreeRatio         = 70
   MaxHeapSize              = 482344960 (460.0MB)
   NewSize                  = 10485760 (10.0MB)
   MaxNewSize               = 160759808 (153.3125MB)
   OldSize                  = 20971520 (20.0MB)
   NewRatio                 = 2
   SurvivorRatio            = 8
   MetaspaceSize            = 21807104 (20.796875MB)
   CompressedClassSpaceSize = 1073741824 (1024.0MB)
   MaxMetaspaceSize         = 17592186044415 MB
   G1HeapRegionSize         = 0 (0.0MB)

Heap Usage:
#新生代内存使用情况 一个eden区域 + 一个Survivor区域
New Generation (Eden + 1 Survivor Space):
   capacity = 9502720 (9.0625MB) 容量
   used     = 4443024 (4.2371978759765625MB) 已使用
   free     = 5059696 (4.8253021240234375MB) 空闲
   46.75528690732759% used 使用百分比
# eden区域
Eden Space:
   capacity = 8454144 (8.0625MB)
   used     = 3649592 (3.4805221557617188MB)
   free     = 4804552 (4.581977844238281MB)
   43.16926704820737% used
# from space 区域 
From Space:
   capacity = 1048576 (1.0MB)
   used     = 793432 (0.7566757202148438MB)
   free     = 255144 (0.24332427978515625MB)
   75.66757202148438% used
# to space 区域
To Space:
   capacity = 1048576 (1.0MB)
   used     = 0 (0.0MB)
   free     = 1048576 (1.0MB)
   0.0% used
#老年代区域
tenured generation:
   capacity = 20971520 (20.0MB)
   used     = 10996744 (10.487312316894531MB)
   free     = 9974776 (9.512687683105469MB)
   52.436561584472656% used

11617 interned Strings occupying 1013400 bytes.