版权声明：杨红岩 https://blog.csdn.net/snxamdf/article/details/89025908
- jps 查看 java 进程信息
- jstack 可查看java进程里的存活线程状态
- jmap 可查看java进程堆内存使用情况
- top linux 命令，可查看java某进程的线程
- jhat 可查看dump文件
- jps
- jps 简单列出java进程
[root@localhost app]# jps
5666 WatchdogServer
5746 XmlAppTransporterContext
5683 Bootstrap
10515 Jps
11929 XmlAppTransporterContext
11915 WatchdogServer- jstack
- jstack [pid] -> jstack 5666 列出指定进程下的线程情况
- jstack [pid] | grep '关键字' -> jstack 5666 | grep 'RUNNABLE' 同上带有过滤
[root@localhost app]# jstack 5666
2019-04-04 16:10:28
Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.181-b13 mixed mode):
"Attach Listener" #30 daemon prio=9 os_prio=0 tid=0x00007f7998002800 nid=0x6bf7 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"pool-4-thread-1" #29 prio=5 os_prio=0 tid=0x00007f798c04b000 nid=0x1664 waiting on condition [0x00007f79bd8d0000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000ca803bf8> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
at java.util.concurrent.ArrayBlockingQueue.take(ArrayBlockingQueue.java:403)
at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
"JMX client heartbeat 3" #28 daemon prio=5 os_prio=0 tid=0x00007f798c041800 nid=0x1663 waiting on condition [0x00007f79bd9d1000]
java.lang.Thread.State: TIMED_WAITING (sleeping)
at java.lang.Thread.sleep(Native Method)
at com.sun.jmx.remote.internal.ClientCommunicatorAdmin$Checker.run(ClientCommunicatorAdmin.java:175)
at java.lang.Thread.run(Thread.java:748)
"RMI RenewClean-[127.0.0.1:37134]" #27 daemon prio=5 os_prio=0 tid=0x00007f798c03f800 nid=0x165f in Object.wait() [0x00007f79bdad2000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)
- locked <0x00000000ca7faaf0> (a java.lang.ref.ReferenceQueue$Lock)
at sun.rmi.transport.DGCClient$EndpointEntry$RenewCleanThread.run(DGCClient.java:563)
at java.lang.Thread.run(Thread.java:748)
"input-stream-pool-1" #26 prio=5 os_prio=0 tid=0x00007f798c015800 nid=0x165b waiting on condition [0x00007f79bddde000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000ca7b5548> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
"input-stream-pool-0" #25 prio=5 os_prio=0 tid=0x00007f798c014000 nid=0x165a runnable [0x00007f79bdedf000]
java.lang.Thread.State: RUNNABLE
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:255)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:286)
at java.io.BufferedInputStream.read(BufferedInputStream.java:345)
- locked <0x00000000ca7c26c8> (a java.lang.UNIXProcess$ProcessPipeInputStream)
at com.creditease.ns4.gear.watchdog.monitor.process.WatchdogChildProcess.readInputStream(WatchdogChildProcess.java:85)
at com.creditease.ns4.gear.watchdog.monitor.process.WatchdogChildProcess.access$000(WatchdogChildProcess.java:38)
at com.creditease.ns4.gear.watchdog.monitor.process.WatchdogChildProcess$1.run(WatchdogChildProcess.java:127)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
"DestroyJavaVM" #24 prio=5 os_prio=0 tid=0x00007f79dc00b000 nid=0x1623 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
- jmap
- jmap -heap [pid] -> jmap -heap 5666 列出指定进程的堆内存使用情况
[root@localhost app]# jmap -heap 5666
Attaching to process ID 5666, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.181-b13
using parallel threads in the new generation.
using thread-local object allocation.
Concurrent Mark-Sweep GC
Heap Configuration:
MinHeapFreeRatio = 40
MaxHeapFreeRatio = 70
MaxHeapSize = 1073741824 (1024.0MB)
NewSize = 174456832 (166.375MB)
MaxNewSize = 174456832 (166.375MB)
OldSize = 899284992 (857.625MB)
NewRatio = 2
SurvivorRatio = 8
MetaspaceSize = 21807104 (20.796875MB)
CompressedClassSpaceSize = 1073741824 (1024.0MB)
MaxMetaspaceSize = 17592186044415 MB
G1HeapRegionSize = 0 (0.0MB)
Heap Usage:
New Generation (Eden + 1 Survivor Space):
capacity = 157024256 (149.75MB)
used = 9306376 (8.875251770019531MB)
free = 147717880 (140.87474822998047MB)
5.926712367291841% used
Eden Space:
capacity = 139591680 (133.125MB)
used = 9306376 (8.875251770019531MB)
free = 130285304 (124.24974822998047MB)
6.666855789686033% used
From Space:
capacity = 17432576 (16.625MB)
used = 0 (0.0MB)
free = 17432576 (16.625MB)
0.0% used
To Space:
capacity = 17432576 (16.625MB)
used = 0 (0.0MB)
free = 17432576 (16.625MB)
0.0% used
concurrent mark-sweep generation:
capacity = 899284992 (857.625MB)
used = 2130744 (2.0320358276367188MB)
free = 897154248 (855.5929641723633MB)
0.2369375691749563% used
4999 interned Strings occupying 395840 bytes.- jmap -histo[:live] [pid] -> jmap -histo:live 5666 关键字live列出存活对象
num #instances #bytes class name
----------------------------------------------
1: 8633 556016 [C
2: 2168 245408 java.lang.Class
3: 8621 206904 java.lang.String
4: 544 188632 [B
5: 1896 101440 [Ljava.lang.Object;
6: 551 48488 java.lang.reflect.Method
7: 873 48064 [I
8: 1382 44224 java.util.HashMap$Node
9: 1303 41696 java.util.concurrent.ConcurrentHashMap$Node
10: 203 23200 [Ljava.util.HashMap$Node;
11: 1143 18288 java.lang.Object
12: 390 15600 java.lang.ref.SoftReference
13: 429 14880 [Ljava.lang.String;
14: 41 14704 [Ljava.util.concurrent.ConcurrentHashMap$Node;
15: 395 12640 java.util.Hashtable$Entry
16: 221 12376 java.lang.invoke.MemberName
17: 480 11608 [Ljava.lang.Class;
18: 239 11472 java.util.HashMap
19: 341 10912 sun.misc.FDBigInteger
20: 24 9024 java.lang.Thread
21: 219 8760 java.util.LinkedHashMap$Entry
22: 291 6984 java.lang.Long
23: 206 6592 java.lang.invoke.LambdaForm$Name
24: 74 6528 [Ljava.util.WeakHashMap$Entry;
25: 102 6528 java.net.URL
26: 158 6320 java.lang.invoke.MethodType
27: 96 5760 [Ljava.lang.ref.SoftReference;
28: 71 5680 java.lang.reflect.Constructor
29: 229 5496 javax.management.ImmutableDescriptor
30: 50 5448 [Ljava.util.Hashtable$Entry;
31: 167 5344 java.lang.invoke.MethodType$ConcurrentWeakInternSet$WeakEntry
32: 166 5312 com.sun.jmx.mbeanserver.ConvertingMethod
33: 126 5040 java.util.WeakHashMap$Entry
34: 279 4464 java.lang.Integer
35: 67 4288 javax.management.openmbean.OpenMBeanAttributeInfoSupport
36: 256 4096 java.lang.Byte
37: 256 4096 java.lang.Short
38: 102 4080 java.lang.ref.Finalizer
39: 123 3936 java.lang.ref.WeakReference
40: 92 3680 java.util.TreeMap$Entry
41: 71 3408 java.util.WeakHashMap
42: 71 3408 java.util.logging.LogManager$LoggerWeakRef
43: 68 3264 java.lang.invoke.LambdaForm
44: 73 3248 [Ljava.lang.invoke.LambdaForm$Name;
45: 173 3144 [Lcom.sun.jmx.mbeanserver.MXBeanMapping;
46: 94 3008 java.lang.ref.ReferenceQueue
47: 54 2968 [Ljavax.management.MBeanAttributeInfo;- class name 列说明
B byte
C char
D double
F float
I int
J long
Z boolean
[ 数组，如[I表示int[] [L+类名 其他对象- jmap -dump:format=b,file=[filename] [pid] -> jmap -dump:format=b,file=./dump.dat 5666 给指定进程生成dump
- jhat -port 9999 ./dump.dat 查看生成的dump，浏览器打开：http://localhost:9999
上面图片是引用其他文章-Other Queries 最后一项支持OQL（对象查询语言）