一、简介
| 名称 | 功能 | 常用命令 |
|---|---|---|
| jps | 显示java程序 | jps -lv |
| jinfo | 显示java进程信息：pid、system Properties 及 arg[] | jinfo pid |
| jconsole | ||
| jstat | java实时监控工具:一般用来调优（gc） | jstat -gc pid 间隔 次数 |
| jstack | java实时监控工具:打印栈信息,一般用来调优、线程运行情况（锁） | jstack -l pid |
| jmap | 是打印堆内存信息，一般都是找BUG，如：死锁、对象大小等等，将数据存放下来，然后在本分析 | jmap -histo pid > 1.txt/jmap -dump:format=b,file=1.bin pid |
jmap、jstatck和jstat的区别是
- jmap:是打印堆内存信息，一般都是找BUG，如：死锁、对象大小等等，将数据存放下来，然后在本分析。
- jstack：获取JVM中线程的信息，用于查找性能点，死锁等。
- jstat:打印gc、class、compiler的实时信息，一般用来调优
二、jps [host]
列出主机上的进程(-v列出具体的信息)
[root@1 tomcat]# jps -v
13781 Jps -Denv.class.path=/usr/local/jdk1.7.0_79/lib:/usr/local/jdk1.7.0_79/jre/lib -Dapplication.home=/usr/local/jdk1.7.0_79 -Xms8m
17541 -- process information unavailable
14661 -- process information unavailable
12224 -- process information unavailable
26343 Bootstrap -Djava.util.logging.config.file=/data/project/dlmall_tomcat_8080/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.endorsed.dirs=/data/project/dlmall_tomcat_8080/endorsed -Dcatalina.base=/data/project/dlmall_tomcat_8080 -Dcatalina.home=/data/project/dlmall_tomcat_8080 -Djava.io.tmpdir=/data/project/dlmall_tomcat_8080/temp
28134 -- process information unavailable
8167 -- process information unavailable
19265 -- process information unavailable
14703 -- process information unavailable
13482 -- process information unavailable
15683 -- process information unavailable
1742 Bootstrap -Djava.util.logging.config.file=/data/project/dlmall_tomcat_8080/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.endorsed.dirs=/data/project/dlmall_tomcat_8080/endorsed -Dcatalina.base=/data/project/dlmall_tomcat_8080 -Dcatalina.home=/data/project/dlmall_tomcat_8080 -Djava.io.tmpdir=/data/project/dlmall_tomcat_8080/temp
1300 Bootstrap -Djava.util.logging.config.file=/data/project/usercenter_tomcat_10224/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.endorsed.dirs=/data/project/usercenter_tomcat_10224/endorsed -Dcatalina.base=/data/project/usercenter_tomcat_10224 -Dcatalina.home=/data/project/usercenter_tomcat_10224 -Djava.io.tmpdir=/data/project/usercenter_tomcat_10224/temp
9356 -- process information unavailable
14781 -- process information unavailable
15357 -- process information unavailable
15019 -- process information unavailable
16988 -- process information unavailable
6308 -- process information unavailable
三、jinfo 输出java进程的信息
[root@1 tomcat]# jinfo 15357
Attaching to process ID 15357, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 24.79-b02
Java System Properties:
java.runtime.name = Java(TM) SE Runtime Environment
java.vm.version = 24.79-b02
sun.boot.library.path = /usr/local/jdk1.7.0_79/jre/lib/amd64
shared.loader =
java.vendor.url = http://java.oracle.com/
java.vm.vendor = Oracle Corporation
path.separator = :
file.encoding.pkg = sun.io
java.vm.name = Java HotSpot(TM) 64-Bit Server VM
java.util.logging.config.file = /data/project/dlpublic_tomcat_10216/conf/logging.properties
tomcat.util.buf.StringCache.byte.enabled = true
sun.os.patch.level = unknown
sun.java.launcher = SUN_STANDARD
user.country = US
user.dir = /data/project
java.vm.specification.name = Java Virtual Machine Specification
java.runtime.version = 1.7.0_79-b15
org.apache.catalina.startup.TldConfig.jarsToSkip = tomcat7-websocket.jar
java.awt.graphicsenv = sun.awt.X11GraphicsEnvironment
os.arch = amd64
java.endorsed.dirs = /data/project/dlpublic_tomcat_10216/endorsed
line.separator =
java.io.tmpdir = /data/project/dlpublic_tomcat_10216/temp
java.vm.specification.vendor = Oracle Corporation
java.util.logging.manager = org.apache.juli.ClassLoaderLogManager
java.naming.factory.url.pkgs = org.apache.naming
os.name = Linux
sun.jnu.encoding = UTF-8
java.library.path = /usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
tomcat.util.scan.DefaultJarScanner.jarsToSkip = bootstrap.jar,commons-daemon.jar,tomcat-juli.jar,annotations-api.jar,el-api.jar,jsp-api.jar,servlet-api.jar,websocket-api.jar,catalina.jar,catalina-ant.jar,catalina-ha.jar,catalina-tribes.jar,jasper.jar,jasper-el.jar,ecj-*.jar,tomcat-api.jar,tomcat-util.jar,tomcat-coyote.jar,tomcat-dbcp.jar,tomcat-jni.jar,tomcat-spdy.jar,tomcat-i18n-en.jar,tomcat-i18n-es.jar,tomcat-i18n-fr.jar,tomcat-i18n-ja.jar,tomcat-juli-adapters.jar,catalina-jmx-remote.jar,catalina-ws.jar,tomcat-jdbc.jar,tools.jar,commons-beanutils*.jar,commons-codec*.jar,commons-collections*.jar,commons-dbcp*.jar,commons-digester*.jar,commons-fileupload*.jar,commons-httpclient*.jar,commons-io*.jar,commons-lang*.jar,commons-logging*.jar,commons-math*.jar,commons-pool*.jar,jstl.jar,taglibs-standard-spec-*.jar,geronimo-spec-jaxrpc*.jar,wsdl4j*.jar,ant.jar,ant-junit*.jar,aspectj*.jar,jmx.jar,h2*.jar,hibernate*.jar,httpclient*.jar,jmx-tools.jar,jta*.jar,log4j.jar,log4j-1*.jar,mail*.jar,slf4j*.jar,xercesImpl.jar,xmlParserAPIs.jar,xml-apis.jar,junit.jar,junit-*.jar,hamcrest*.jar,org.hamcrest*.jar,ant-launcher.jar,cobertura-*.jar,asm-*.jar,dom4j-*.jar,icu4j-*.jar,jaxen-*.jar,jdom-*.jar,jetty-*.jar,oro-*.jar,servlet-api-*.jar,tagsoup-*.jar,xmlParserAPIs-*.jar,xom-*.jar
java.class.version = 51.0
java.specification.name = Java Platform API Specification
sun.management.compiler = HotSpot 64-Bit Tiered Compilers
os.version = 3.10.0-229.el7.x86_64
user.home = /home/tomcat
org.apache.catalina.startup.ContextConfig.jarsToSkip =
user.timezone = Asia/Chungking
catalina.useNaming = true
java.awt.printerjob = sun.print.PSPrinterJob
file.encoding = UTF-8
java.specification.version = 1.7
catalina.home = /data/project/dlpublic_tomcat_10216
user.name = tomcat
java.class.path = /data/project/dlpublic_tomcat_10216/bin/bootstrap.jar:/data/project/dlpublic_tomcat_10216/bin/tomcat-juli.jar
java.naming.factory.initial = org.apache.naming.java.javaURLContextFactory
package.definition = sun.,java.,org.apache.catalina.,org.apache.coyote.,org.apache.jasper.,org.apache.naming.,org.apache.tomcat.
java.vm.specification.version = 1.7
sun.arch.data.model = 64
sun.java.command = org.apache.catalina.startup.Bootstrap start
java.home = /usr/local/jdk1.7.0_79/jre
user.language = en
java.specification.vendor = Oracle Corporation
awt.toolkit = sun.awt.X11.XToolkit
java.vm.info = mixed mode
java.version = 1.7.0_79
java.ext.dirs = /usr/local/jdk1.7.0_79/jre/lib/ext:/usr/java/packages/lib/ext
sun.boot.class.path = /usr/local/jdk1.7.0_79/jre/lib/resources.jar:/usr/local/jdk1.7.0_79/jre/lib/rt.jar:/usr/local/jdk1.7.0_79/jre/lib/sunrsasign.jar:/usr/local/jdk1.7.0_79/jre/lib/jsse.jar:/usr/local/jdk1.7.0_79/jre/lib/jce.jar:/usr/local/jdk1.7.0_79/jre/lib/charsets.jar:/usr/local/jdk1.7.0_79/jre/lib/jfr.jar:/usr/local/jdk1.7.0_79/jre/classes
server.loader =
java.vendor = Oracle Corporation
catalina.base = /data/project/dlpublic_tomcat_10216
file.separator = /
java.vendor.url.bug = http://bugreport.sun.com/bugreport/
common.loader = ${catalina.base}/lib,${catalina.base}/lib/*.jar,${catalina.home}/lib,${catalina.home}/lib/*.jar
sun.io.unicode.encoding = UnicodeLittle
sun.cpu.endian = little
package.access = sun.,org.apache.catalina.,org.apache.coyote.,org.apache.jasper.,org.apache.naming.resources.,org.apache.tomcat.
dlpublic.root = /data/project/dlpublic_tomcat_10216/temp/0-ROOT/
sun.cpu.isalist =
VM Flags:
-Djava.util.logging.config.file=/data/project/dlpublic_tomcat_10216/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -XX:PermSize=64M -XX:MaxPermSize=128m -Xms512M -Xmx1024M -XX:MaxNewSize=64m -Djava.endorsed.dirs=/data/project/dlpublic_tomcat_10216/endorsed -Dcatalina.base=/data/project/dlpublic_tomcat_10216 -Dcatalina.home=/data/project/dlpublic_tomcat_10216 -Djava.io.tmpdir=/data/project/dlpublic_tomcat_10216/temp
四、jconsole
在CMD中使用jconsole 会使用jconsole的分析工具
五、jmap
用途：观察运行中的jvm物理内存的占用情况，包括Heap size, Perm size等等。
-heap：打印jvm heap的情况
-histo：打印jvm heap的直方图。其输出信息包括类名，对象数量，对象占用大小。
-histo：live ：同上，但是只答应存活对象的情况
-permstat：打印permanent generation heap情况
打印对象
[tomcat@1 ~]$ jmap -histo 6308 > 1.txt
[tomcat@1 ~]$ less 1.txt
num #instances #bytes class name
----------------------------------------------
1: 798603 60145800 [C
2: 138032 51259048 [B
3: 138630 22365576 <constMethodKlass>
4: 15705 17838152 <constantPoolKlass>
5: 138630 17761120 <methodKlass>
6: 100021 15367808 [I
7: 15705 11664816 <instanceKlassKlass>
8: 12995 9695776 <constantPoolCacheKlass>
9: 401014 9624336 java.lang.String
10: 117855 5835624 [Ljava.lang.Object;
11: 125178 4005696 java.util.HashMap$Entry
12: 50001 4000080 java.lang.reflect.Method
13: 82636 3966528 java.nio.HeapCharBuffer
14: 6165 3514376 <methodDataKlass>
15: 32845 3463040 [Ljava.util.HashMap$Entry;
16: 83804 3352160 java.util.LinkedHashMap$Entry
17: 24894 2904600 [S
18: 42082 2356592 java.util.LinkedHashMap
19: 30932 1979648 java.util.regex.Matcher
20: 16413 1547616 java.lang.Class
21: 56050 1345200 java.util.ArrayList
22: 24454 1202360 [[I
23: 24325 1167600 java.util.HashMap
24: 36116 1155712 java.util.Hashtable$Entry
25: 35515 1136480 java.util.concurrent.ConcurrentHashMap$HashEntry
26: 42637 1023288 java.lang.StringBuilder
27: 15876 1016064 java.net.URL
28: 40710 977040 java.util.concurrent.atomic.AtomicLong
29: 12530 902160 java.lang.reflect.Field
30: 17962 840968 [Ljava.lang.String;
31: 17976 719040 java.lang.ref.SoftReference
32: 21678 693696 java.lang.StackTraceElement
33: 21284 681088 java.lang.ref.WeakReference
34: 27898 669552 java.io.ObjectInputStream$HandleTable$HandleList
35: 16683 667320 java.util.TreeMap$Entry
36: 8901 640872 java.lang.reflect.Constructor
37: 29741 618280 [Ljava.lang.Class;
7042: 1 16 sun.reflect.GeneratedMethodAccessor201
7043: 1 16 org.apache.commons.collections.iterators.EmptyOrderedMapIterator
7044: 1 16 com.google.inject.internal.guava.collect.$Iterators$1
7045: 1 16 sun.reflect.GeneratedMethodAccessor736
7046: 1 16 jenkins.branch.NoTriggerOrganizationFolderProperty$Dispatcher
7047: 1 16 jenkins.model.GlobalNodePropertiesConfiguration$$FastClassByGuice$$e6707da1
7048: 1 16 sun.reflect.GeneratedMethodAccessor29
7049: 1 16 hudson.cli.ListPluginsCommand$$FastClassByGuice$$9650998a
7050: 1 16 sun.reflect.GeneratedMethodAccessor438
7051: 1 16 sun.reflect.GeneratedMethodAccessor474
7052: 1 16 sun.reflect.GeneratedMethodAccessor699
7053: 1 16 hudson.plugins.deploy.DeployPublisher$DescriptorImpl$$FastClassByGuice$$ef30e0c4
7054: 1 16 hudson.matrix.DefaultMatrixExecutionStrategyImpl$DescriptorImpl$$FastClassByGuice$$ce3ec170
7055: 1 16 org.jenkinsci.bytecode.Transformer
7056: 1 16 net.sf.json.util.JavaIdentifierTransformer$UnderscoreJavaIdentifierTransformer
7057: 1 16 java.security.ProtectionDomain$1
7058: 1 16 org.sonatype.plexus.components.sec.dispatcher.DefaultSecDispatcher$__sisu12$$FastClassByGuice$$6869d82e
7059: 1 16 hudson.plugins.emailext.plugins.trigger.FailureTrigger$DescriptorImpl$$FastClassByGuice$$9cb01b39
7060: 1 16 sun.reflect.GeneratedMethodAccessor804
Total 3662258 295584784
打印堆中的信息
[tomcat@1 ~]$ jmap -heap 6308
Attaching to process ID 6308, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 24.79-b02
using thread-local object allocation.
Parallel GC with 4 thread(s)
Heap Configuration:
MinHeapFreeRatio = 0
MaxHeapFreeRatio = 100
MaxHeapSize = 1073741824 (1024.0MB)
NewSize = 1310720 (1.25MB)
MaxNewSize = 134217728 (128.0MB)
OldSize = 5439488 (5.1875MB)
NewRatio = 2
SurvivorRatio = 8
PermSize = 268435456 (256.0MB)
MaxPermSize = 536870912 (512.0MB)
G1HeapRegionSize = 0 (0.0MB)
Heap Usage:
PS Young Generation
Eden Space:
capacity = 110100480 (105.0MB)
used = 7671208 (7.315834045410156MB)
free = 102429272 (97.68416595458984MB)
6.96746099562872% used
From Space:
capacity = 12058624 (11.5MB)
used = 6324288 (6.03131103515625MB)
free = 5734336 (5.46868896484375MB)
52.44618291440217% used
To Space:
capacity = 11534336 (11.0MB)
used = 0 (0.0MB)
free = 11534336 (11.0MB)
0.0% used
PS Old Generation
capacity = 402653184 (384.0MB)
used = 101235008 (96.54522705078125MB)
free = 301418176 (287.45477294921875MB)
25.14198621114095% used
PS Perm Generation
capacity = 268435456 (256.0MB)
used = 88806056 (84.69205474853516MB)
free = 179629400 (171.30794525146484MB)
33.082833886146545% used
38659 interned Strings occupying 4321264 bytes.
打印内存信息，生成2进制文件，用来分析
[tomcat@1 ~]$ jmap -dump:format=b,file=1.bin 6308
Dumping heap to /home/tomcat/1.bin ...
Heap dump file created
##会生成一个2进制文件，然后可以加载到本地来分析。
六、jstat
- jstat：java实时监控工具，一般用来调优（gc）
- 命令
jstat -<option> [-t] [-h<lines>] <vmid> [<interval> [<count>]]
- 参数
-class：统计class loader行为信息
-compile：统计编译行为信息
-gc：统计jdk gc时heap信息
-gccapacity：统计不同的generations（不知道怎么翻译好，包括新生区，老年区，permanent区）相应的heap容量情况
-gccause：统计gc的情况，（同-gcutil）和引起gc的事件
-gcnew：统计gc时，新生代的情况
-gcnewcapacity：统计gc时，新生代heap容量
-gcold：统计gc时，老年区的情况
-gcoldcapacity：统计gc时，老年区heap容量
-gcpermcapacity：统计gc时，permanent区heap容量
-gcutil：统计gc时，heap情况
- 打印class的实时数据
打印pid=6308的实时class信息，没1000ms打印一次，总共打印5次
[tomcat@1 ~]$ jstat -class 6308 1000 5
Loaded Bytes Unloaded Bytes Time
18861 34897.7 3122 3776.6 11.91
18861 34897.7 3122 3776.6 11.91
18861 34897.7 3122 3776.6 11.91
18861 34897.7 3122 3776.6 11.91
18861 34897.7 3122 3776.6 11.91
- 打印实时编译的class
[tomcat@1 ~]$ jstat -compiler 6308
Compiled Failed Invalid Time FailedType FailedMethod
3780 1 0 120.26 2 com/xxx/xxx run
- 打印gc的信息参数信息
S0C：Current survivor space 0 capacity (当前S0的大小).
S1C：Current survivor space 1 capacity (KB).
S0U：Current survivor space 0 utilization (KB)(当前S0的可用大小).
S1U：Current survivor space 1 utilization(KB).
EC：Current eden space capacity(KB).
EU：Eden space utilization(KB).
OC：Current old space capacity(KB).
OU：Old space utilization (KB).
PC：Current permanent space capacity (KB).
PU：Permanent space utilization (KB).
YGC：Number of young generation GC Events.
YGCT：Young generation garbage collection time.
FGC：Number of full GC events.
FGCT：Full garbage collection time.
GCT：Total garbage collection time.
- 打印gc的信息（百分比）
[tomcat@1 ~]$ jstat -gcutil 6308 1000 5
S0 S1 E O P YGC YGCT FGC FGCT GCT
0.00 3.13 24.21 26.43 33.11 987 13.012 3 2.524 15.536
0.00 3.13 24.21 26.43 33.11 987 13.012 3 2.524 15.536
0.00 3.13 24.21 26.43 33.11 987 13.012 3 2.524 15.536
0.00 3.13 24.21 26.43 33.11 987 13.012 3 2.524 15.536
0.00 3.13 24.21 26.43 33.11 987 13.012 3 2.524 15.536
- 打印gc数据(具体)
[tomcat@1 ~]$ jstat -gc 6308 1000 5
S0C S1C S0U S1U EC EU OC OU PC PU YGC YGCT FGC FGCT GCT
12288.0 14336.0 7776.0 0.0 102400.0 1417.3 393216.0 103757.4 262144.0 86786.8 984 12.989 3 2.524 15.513
12288.0 14336.0 7776.0 0.0 102400.0 1473.8 393216.0 103757.4 262144.0 86786.8 984 12.989 3 2.524 15.513
12288.0 14336.0 7776.0 0.0 102400.0 1491.6 393216.0 103757.4 262144.0 86786.8 984 12.989 3 2.524 15.513
12288.0 14336.0 7776.0 0.0 102400.0 1495.8 393216.0 103757.4 262144.0 86786.8 984 12.989 3 2.524 15.513
12288.0 14336.0 7776.0 0.0 102400.0 1510.6 393216.0 103757.4 262144.0 86786.8 984 12.989 3 2.524 15.513
- 打印perm、new、old的信息
[tomcat@1 ~]$ jstat -gccapacity 6308 1000 5
NGCMN NGCMX NGC S0C S1C EC OGCMN OGCMX OGC OC PGCMN PGCMX PGC PC YGC FGC
131072.0 131072.0 131072.0 14336.0 14848.0 101376.0 393216.0 917504.0 393216.0 393216.0 262144.0 524288.0 262144.0 262144.0 987 3
131072.0 131072.0 131072.0 14336.0 14848.0 101376.0 393216.0 917504.0 393216.0 393216.0 262144.0 524288.0 262144.0 262144.0 987 3
131072.0 131072.0 131072.0 14336.0 14848.0 101376.0 393216.0 917504.0 393216.0 393216.0 262144.0 524288.0 262144.0 262144.0 987 3
131072.0 131072.0 131072.0 14336.0 14848.0 101376.0 393216.0 917504.0 393216.0 393216.0 262144.0 524288.0 262144.0 262144.0 987 3
131072.0 131072.0 131072.0 14336.0 14848.0 101376.0 393216.0 917504.0 393216.0 393216.0 262144.0 524288.0 262144.0 262144.0 987 3
七、jstack
- jstack：打印栈信息，java实时监控工具，一般用来调优（锁）
- 命令
jstack [-l] <pid>
- 参数
-l：列出当前java应用的线程状态
- 用 top列出CPU消耗高的java应用
[tomcat@idanlu-kaifa-63 ~]$ top
top - 13:59:44 up 63 days, 21:46, 5 users, load average: 0.15, 0.15, 0.19
Tasks: 169 total, 1 running, 168 sleeping, 0 stopped, 0 zombie
%Cpu(s): 1.7 us, 1.3 sy, 0.0 ni, 96.9 id, 0.0 wa, 0.0 hi, 0.1 si, 0.0 st
KiB Mem : 40070540 total, 586648 free, 32520668 used, 6963224 buff/cache
KiB Swap: 2097148 total, 2120 free, 2095028 used. 7169184 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
4062 tomcat 20 0 3039200 568372 4936 S 1.0 1.4 1358:19 java
16372 tomcat 20 0 3290404 699572 23480 S 1.0 1.7 5:11.30 java
16657 tomcat 20 0 3072308 650000 23460 S 1.0 1.6 7:00.49 java
17701 tomcat 20 0 3544120 1.195g 12040 S 0.7 3.1 1:39.45 java
19372 tomcat 20 0 3056204 295384 5860 S 0.7 0.7 41:29.62 java
28021 tomcat 20 0 3774392 1.215g 11832 S 0.7 3.2 58:19.12 java
- 用 top -Hl pid 显示应用中的线程运行状态
[tomcat@idanlu-kaifa-63 ~]$ top -Hp 4062
top - 14:02:19 up 63 days, 21:49, 5 users, load average: 0.09, 0.14, 0.18
Threads: 60 total, 0 running, 60 sleeping, 0 stopped, 0 zombie
%Cpu(s): 1.5 us, 1.3 sy, 0.0 ni, 97.1 id, 0.1 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 40070540 total, 583372 free, 32521324 used, 6965844 buff/cache
KiB Swap: 2097148 total, 2120 free, 2095028 used. 7168508 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
4127 tomcat 20 0 3039200 568372 4936 S 0.3 1.4 4:10.92 java
4062 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:00.00 java
4070 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:08.77 java
4071 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:05.45 java
4072 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:05.46 java
4073 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:05.38 java
4074 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:05.38 java
4075 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 2:25.77 java
4076 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:00.02 java
4077 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:00.03 java
4078 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:00.00 java
4079 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:14.96 java
4080 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:12.26 java
4081 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:00.00 java
4082 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 36:12.95 java
4089 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:42.04 java
4090 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:00.72 java
4091 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 1:16.72 java
4092 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:00.03 java
4093 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 0:01.84 java
4094 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 3:57.18 java
4095 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 3:55.29 java
4096 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 3:56.72 java
4097 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 4:04.82 java
4098 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 3:53.77 java
4099 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 4:48.47 java
4100 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 2:38.50 java
4102 tomcat 20 0 3039200 568372 4936 S 0.0 1.4 1164:36 java
- 选取运行CPU高，时长长的线程tid。转换为16位
[tomcat@idanlu-kaifa-63 ~]$ printf "%x\n" 4102
101f
- 用jstack -l pid> 1.txt 打印应用的线程情况，间隔一段时间，多打印几次。查找相关 nid
"notify-remoting-reactor-0" prio=10 tid=0x00007f03ed0b3000 nid=0x101f runnable [0x00007f03e0ad1000]
java.lang.Thread.State: RUNNABLE
at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:79)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:87)
- locked <0x00000000e0f4a698> (a sun.nio.ch.Util$2)
- locked <0x00000000e0f4a688> (a java.util.Collections$UnmodifiableSet)
- locked <0x00000000e0f4a570> (a sun.nio.ch.EPollSelectorImpl)
at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:98)
at com.taobao.gecko.core.nio.impl.Reactor.select(Reactor.java:334)
at com.taobao.gecko.core.nio.impl.Reactor.run(Reactor.java:236)
【推荐】国内首个AI IDE，深度理解中文开发场景，立即下载体验Trae
【推荐】编程新体验，更懂你的AI，立即体验豆包MarsCode编程助手
【推荐】抖音旗下AI助手豆包，你的智能百科全书，全免费不限次数
【推荐】轻量又高性能的 SSH 工具 IShell：AI 加持，快人一步
· winform 绘制太阳，地球，月球 运作规律
· 超详细：普通电脑也行Windows部署deepseek R1训练数据并当服务器共享给他人
· 上周热点回顾（3.3-3.9）
· AI 智能体引爆开源社区「GitHub 热点速览」
· 写一个简单的SQL生成工具