Arthas 是 Alibaba 开源的 Java 诊断工具
方式一：使用
arthas-boot（Linux推荐）
下载arthas-boot.jar，然后用java -jar的方式启动：
curl -O https://arthas.aliyun.com/arthas-boot.jar
java -jar arthas-boot.jar
如果下载速度比较慢，可以使用 aliyun 的镜像：
java -jar arthas-boot.jar --repo-mirror aliyun --use-http
方式二：全量安装（Windows推荐）
解压后，在文件夹里有arthas-boot.jar，直接用java -jar的方式启动：
java -jar arthas-boot.jar
打印帮助信息：
java -jar arthas-boot.jar -h
arthas是基于依赖JDK环境运行，要配置JDK环境变量，只有jre环境不行，启动时内部依赖jps命令，如果机器jps找不到命令，arthas无法启动。
直接运行arthas-boot.jar
C:\cvzhanshi\workspace\arthas-packaging-3.6.6-bin>java -jar arthas-boot.jar
[INFO] arthas-boot version: 3.6.6
[INFO] Process 10520 already using port 3658
[INFO] Process 10520 already using port 8563
[INFO] Found existing java process, please choose one and input the serial number of the process, eg : 1. Then hit ENTER.
* [1]: 10520 cn.cvzhanshi.TestApplication
[2]: 19600
[3]: 13604 org.jetbrains.idea.maven.server.RemoteMavenServer36
[4]: 11752 org.apache.zookeeper.server.quorum.QuorumPeerMain
[5]: 2376 org.jetbrains.jps.cmdline.Launcher
[6]: 24712 C:\cvzhanshi\environment\nacos\target\nacos-server.jar
[7]: 7656 org.jetbrains.jps.cmdline.Launcher
[8]: 15484 org.jetbrains.jps.cmdline.Launcher
[9]: 8124 org.jetbrains.jps.cmdline.Launcher
admin用户来执行：sudo su admin && java -jar arthas-boot.jar 或 sudo -u admin -EH java -jar arthas-boot.jar。~/logs/arthas/ 目录下的日志。java -jar arthas-boot.jar --repo-mirror aliyun --use-httpjava -jar arthas-boot.jar -h 打印更多参数信息。选择需要诊断的java进程的编号，回车，进入命令行。
.java文件为.class文件.class文件，redefine 到 JVM 里.class文件，retransform 到 JVM 里注意
请注意，这些命令，都通过字节码增强技术来实现的，会在指定类的方法中插入一些切面来实现数据统计和观测，因此在线上、预发使用时，请尽量明确需要观测的类、方法以及条件，诊断结束要执行
stop或将增强过的类执行reset命令。
Arthas 支持使用管道对上述命令的结果进行进一步的处理，如sm java.lang.String * | grep 'index'
当线上出现偶发的问题，比如需要 watch 某个条件，而这个条件一天可能才会出现一次时，异步后台任务就派上用场了，详情请参考这里
> 将结果重写向到日志文件，使用 & 指定命令是后台运行，session 断开不影响任务执行（生命周期默认为 1 天）[arthas@10520]$ help
NAME DESCRIPTION
help Display Arthas Help
auth Authenticates the current session
keymap Display all the available keymap for the specified connection.
sc Search all the classes loaded by JVM
sm Search the method of classes loaded by JVM
classloader Show classloader info
jad Decompile class
getstatic Show the static field of a class
monitor Monitor method execution statistics, e.g. total/success/failure count, average rt, fail rate, etc.
stack Display the stack trace for the specified class and method
thread Display thread info, thread stack
trace Trace the execution time of specified method invocation.
watch Display the input/output parameter, return object, and thrown exception of specified method invocation
tt Time Tunnel
jvm Display the target JVM information
memory Display jvm memory info.
perfcounter Display the perf counter information.
ognl Execute ognl expression.
mc Memory compiler, compiles java files into bytecode and class files in memory.
redefine Redefine classes. @see Instrumentation#redefineClasses(ClassDefinition...)
retransform Retransform classes. @see Instrumentation#retransformClasses(Class...)
dashboard Overview of target jvm's thread, memory, gc, vm, tomcat info.
dump Dump class byte array from JVM
heapdump Heap dump
options View and change various Arthas options
cls Clear the screen
reset Reset all the enhanced classes
version Display Arthas version
session Display current session information
sysprop Display, and change the system properties.
sysenv Display the system env.
vmoption Display, and update the vm diagnostic options.
logger Print logger info, and update the logger level
history Display command history
cat Concatenate and print files
base64 Encode and decode using Base64 representation
echo write arguments to the standard output
pwd Return working directory name
mbean Display the mbean information
grep grep command for pipes.
tee tee command for pipes.
profiler Async Profiler. https://github.com/jvm-profiling-tools/async-profiler
vmtool jvm tool
stop Stop/Shutdown Arthas server and exit the console.
其中每个命令都可以加-help或者-h选项，打印帮助信息
反编译类或方法
[arthas@10520]$ jad cn.cvzhanshi.TestApplication
ClassLoader:
+-sun.misc.Launcher$AppClassLoader@58644d46
+-sun.misc.Launcher$ExtClassLoader@1996cd68
Location:
/C:/cvzhanshi/workspace/BootTest/target/classes/
/*
* Decompiled with CFR.
*/
package cn.cvzhanshi;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class TestApplication {
public static void main(String[] args) {
/*10*/ SpringApplication.run(TestApplication.class, args);
}
}
Affect(row-cnt:2) cost in 874 ms.
反编译方法
[arthas@10520]$ jad cn.cvzhanshi.TestApplication getInitPara
打印方法的调用堆栈信息，当不知道某个方法从哪里被调用使时，推荐使用。
stack cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl listAllQuickCheck
可以指定添加表达式
target : the object
clazz : the object's class
method : the constructor or method
params : the parameters array of method
params[0..n] : the element of parameters array
returnObj : the returned object of method
throwExp : the throw exception of method
isReturn : the method ended by return
isThrow : the method ended by throwing exception
#cost : the execution time in ms of method invocation
如果某个方法有重载，可以指定 ‘params.length==2’，是否有返回值’isReturn==true’
| 参数名称 | 参数说明 |
|---|---|
| class-pattern | 类名表达式匹配 |
| method-pattern | 方法名表达式匹配 |
| condition-express | 条件表达式 |
| [E] | 开启正则表达式匹配，默认为通配符匹配 |
[n:] | 执行次数限制v |
这里重点要说明的是观察表达式，观察表达式的构成主要由 ognl 表达式组成，所以你可以这样写"{params,returnObj}"，只要是一个合法的 ognl 表达式，都能被正常支持。
检测指定方法的执行时间，分析性能问题常用。可以显示方法总耗时，方法内部每个方法的耗时
[arthas@22249]$ trace cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl listAllQuickCheck
Press Q or Ctrl+C to abort.
Affect(class count: 2 , method count: 2) cost in 453 ms, listenerId: 12
`---ts=2022-09-25 16:16:26;thread_name=https-jsse-nio-7443-exec-9;id=7c;is_daemon=true;priority=5;TCCL=org.apache.catalina.loader.ParallelWebappClassLoader@5e5d171f
`---[29.427293ms] cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl$$EnhancerBySpringCGLIB$$9a53710:listAllQuickCheck()
`---[29.269844ms] org.springframework.cglib.proxy.MethodInterceptor:intercept()
`---[27.574802ms] cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl:listAllQuickCheck()
+---[0.043715ms] cn.cvzhanshi.project.quickcheck.vo.ReturnVO:<init>() #1252
+---[0.045866ms] cn.cvzhanshi.project.system.cache.ICacheService:getQuickVOs() #1257
+---[0.017484ms] cn.cvzhanshi.project.system.cache.ICacheService:getQuickVOs() #1283
+---[0.335878ms] org.slf4j.Logger:info() #1288
+---[min=0.010004ms,max=0.021479ms,total=0.031483ms,count=2] cn.cvzhanshi.project.quickcheck.vo.QueryVO:getPage() #1290
+---[0.01918ms] cn.cvzhanshi.project.system.common.Page:getCheckType() #1290
+---[0.032272ms] cn.cvzhanshi.project.system.user.vo.UserVO:getPkOrg() #1297
+---[0.024467ms] cn.cvzhanshi.project.system.common.DataAuth:getSubUsers() #1297
+---[6.412332ms] cn.cvzhanshi.project.system.common.DataAuth:getAdminsInSameOrg() #1298
+---[0.027311ms] cn.cvzhanshi.project.system.common.DataAuth:getQueryConditions2() #1299
+---[0.014522ms] cn.cvzhanshi.project.quickcheck.vo.QueryVO:getConditions() #1315
+---[0.355064ms] org.slf4j.Logger:info() #1374
+---[0.019006ms] cn.cvzhanshi.project.quickcheck.vo.ReturnVO:setTotalCount() #1377
+---[0.139323ms] org.slf4j.Logger:info() #1378
+---[0.010446ms] cn.cvzhanshi.project.quickcheck.vo.QueryVO:getPage() #1379
+---[0.015853ms] cn.cvzhanshi.project.system.common.Page:getPageIndex() #1383
+---[0.017482ms] cn.cvzhanshi.project.system.common.Page:getPageSize() #1383
+---[0.118588ms] org.slf4j.Logger:info() #1384
+---[0.031007ms] cn.cvzhanshi.project.quickcheck.vo.ReturnVO:setQuickVOS() #1398
`---[0.125891ms] org.slf4j.Logger:info() #1420
| 参数名称 | 参数说明 |
|---|---|
| class-pattern | 类名表达式匹配 |
| method-pattern | 方法名表达式匹配 |
| condition-express | 条件表达式 |
| [E] | 开启正则表达式匹配，默认为通配符匹配 |
[n:] | 命令执行次数 |
#cost | 方法执行耗时 |
这里重点要说明的是观察表达式，观察表达式的构成主要由 ognl 表达式组成，所以你可以这样写"{params,returnObj}"，只要是一个合法的 ognl 表达式，都能被正常支持。
监控方法的入参，出参，返回值，异常信息。分析代码运行逻辑错误常用
[arthas@22249]$ watch cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl listAllQuickCheck
Press Q or Ctrl+C to abort.
Affect(class count: 2 , method count: 2) cost in 325 ms, listenerId: 13
method=cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl.listAllQuickCheck location=AtExit
ts=2022-09-25 16:20:52; [cost=26.88488ms] result=@ArrayList[
@Object[][isEmpty=false;size=2],
@QuickCheckServiceImpl[cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl@1d93574],
@ReturnVO[ReturnVO(totalCount=12, quickVOS=[QuickVO [pkTemplate=null, pkQuick=10, pkCode=12, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=10, pkCode=12, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=9, pkCode=11, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=9, pkCode=11, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=8, pkCode=10, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=7, pkCode=8, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=null], QuickVO [pkTemplate=null, pkQuick=6, pkCode=7, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=5, pkCode=6, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=4, pkCode=5, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=3, pkCode=4, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=2, pkCode=3, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=], QuickVO [pkTemplate=null, pkQuick=1, pkCode=1, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]])],
]
location=AtExit，标识正常结束，AtExceptionExit异常退出
如果只想打印入参和出参，可以添加’{params,returnObj}'。
如果想打印更详细的参数内部信息，可以执行 -x选项，-x 2标识展开参数内部一层属性，例如：
[arthas@22249]$ watch cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl listAllQuickCheck '{params,returnObj}' -x 2
Press Q or Ctrl+C to abort.
Affect(class count: 2 , method count: 2) cost in 317 ms, listenerId: 15
method=cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl.listAllQuickCheck location=AtExit
ts=2022-09-25 16:27:00; [cost=27.125728ms] result=@ArrayList[
@Object[][
@UserVO[UserVO(username=admin, remark=超级管理员)],
@QueryVO[QueryVO(conditions=null, page=Page(pageIndex=0, pageSize=15, checkType=0), dataAuthConditions=null)],
],
@ReturnVO[
serialVersionUID=@Long[2869465919425993293],
totalCount=@Integer[12],
quickVOS=@ArrayList[isEmpty=false;size=12],
],
]
再深一层，指定-x 3
[arthas@22249]$ watch cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl listAllQuickCheck '{params,returnObj}' -x 3
Press Q or Ctrl+C to abort.
Affect(class count: 2 , method count: 2) cost in 313 ms, listenerId: 16
method=cn.cvzhanshi.project.quickcheck.service.impl.QuickCheckServiceImpl.listAllQuickCheck location=AtExit
ts=2022-09-25 16:30:58; [cost=29.749962ms] result=@ArrayList[
@Object[][
@UserVO[
serialVersionUID=@Long[1],
IS_SYS_INIT=@String[Y],
NOT_SYS_INIT=@String[N],
IS_FROZEN=@String[Y],
NOT_FROZEN=@String[N],
USER_NAME_MAX_LENGTH=@Integer[50],
USER_PASSWORD_MAX_LENGTH=@Integer[30],
USER_REMARK_MAX_LENGTH=@Integer[500],
USER_SVNGIT_URL_MAX_LENGTH=@Integer[1000],
USER_PASSWORD_MIN_LENGTH=@Integer[8],
USER_EMAIL_MAX_LENGTH=@Integer[200],
USER_PHONE_MAX_LENGTH=@Integer[50],
pkUser=@Long[1],
username=@String[admin],
displayName=null,
password=null,
phone=null,
email=null,
remark=@String[超级管理员],
pkOrg=@Long[1],
orgName=@String[系统默认],
roleName=null,
pkRole=null,
isFirst=@Integer[0],
isInit=@String[Y],
leader=null,
leaderName=null,
roles=@ArrayList[isEmpty=false;size=1],
roleList=null,
svnGits=null,
isFrozen=null,
isDel=null,
type=@Integer[1],
isAdmin=@Boolean[true],
disabled=null,
enablePlatform=@Integer[0],
authorities=@UnmodifiableSet[isEmpty=false;size=177],
accountNonExpired=@Boolean[true],
accountNonLocked=@Boolean[true],
credentialsNonExpired=@Boolean[true],
enabled=@Boolean[true],
includeDeleted=null,
license=null,
captcha=null,
orgChains=null,
],
@QueryVO[
serialVersionUID=@Long[4880479368610906456],
conditions=null,
page=@Page[Page(pageIndex=0, pageSize=15, checkType=0)],
dataAuthConditions=null,
],
],
@ReturnVO[
serialVersionUID=@Long[2869465919425993293],
totalCount=@Integer[12],
quickVOS=@ArrayList[
@QuickVO[QuickVO [pkTemplate=null, pkQuick=10, pkCode=12, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=10, pkCode=12, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=9, pkCode=11, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=9, pkCode=11, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=8, pkCode=10, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=7, pkCode=8, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=null]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=6, pkCode=7, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=5, pkCode=6, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=4, pkCode=5, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=3, pkCode=4, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=2, pkCode=3, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
@QuickVO[QuickVO [pkTemplate=null, pkQuick=1, pkCode=1, checkType=0, pkUser=1, user_name=admin, quickPerm=0, auditPkTask=null, disabled=false, taskDesc=]],
],
],
]
显示jvm信息
[arthas@22249]$ jvm
RUNTIME
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MACHINE-NAME 22249@localhost.localdomain
JVM-START-TIME 2022-08-24 11:16:20
MANAGEMENT-SPEC-VERSION 1.2
SPEC-NAME Java Virtual Machine Specification
SPEC-VENDOR Oracle Corporation
SPEC-VERSION 1.8
VM-NAME Java HotSpot(TM) 64-Bit Server VM
VM-VENDOR Oracle Corporation
VM-VERSION 25.144-b01
INPUT-ARGUMENTS -Djava.util.logging.config.file=/usr/local/project/projectserver/conf/logging.properties
-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
-Xms20G
-Xmx20G
-Djdk.tls.ephemeralDHKeySize=2048
输入dashboard，按回车/enter，会展示当前进程的信息，按ctrl+c可以中断执行。
监控jvm线程，内存，gc信息
可加参数：
-h 帮助信息
-n 监控次数
-i 刷新间隔
# -n监控一次就结束
[arthas@10520]$ dashboard -n 1
ID NAME GROUP PRIORITY STATE %CPU DELTA_TIM TIME INTERRUPT DAEMON
41 DestroyJavaVM main 5 RUNNABLE 0.0 0.000 0:3.921 false false
35 cluster_scheduler_QuartzSched QuartzSchedule 5 TIMED_WA 0.0 0.000 0:2.687 false false
-1 C1 CompilerThread3 - -1 - 0.0 0.000 0:2.140 false true
39 QuartzScheduler_cluster_sched main 7 TIMED_WA 0.0 0.000 0:0.406 false false
83 arthas-NettyWebsocketTtyBoots system 5 RUNNABLE 0.0 0.000 0:0.265 false true
13 RMI TCP Accept-0 system 5 RUNNABLE 0.0 0.000 0:0.234 false true
31 cluster_scheduler_Worker-2 main 5 TIMED_WA 0.0 0.000 0:0.125 false false
-1 VM Thread - -1 - 0.0 0.000 0:0.125 false true
30 cluster_scheduler_Worker-1 main 5 TIMED_WA 0.0 0.000 0:0.109 false false
89 arthas-NettyHttpTelnetBootstr system 5 RUNNABLE 0.0 0.000 0:0.078 false true
34 cluster_scheduler_Worker-5 main 5 TIMED_WA 0.0 0.000 0:0.078 false false
Memory used total max usage GC
heap 74M 328M 3621M 2.05% gc.ps_scavenge.count 8
ps_eden_space 28M 163M 1323M 2.13% gc.ps_scavenge.time(ms) 68
ps_survivor_space 12M 13M 13M 99.82% gc.ps_marksweep.count 2
ps_old_gen 33M 152M 2716M 1.22% gc.ps_marksweep.time(ms) 67
nonheap 71M 74M -1 95.47%
code_cache 10M 10M 240M 4.44%
metaspace 53M 56M -1 94.90%
compressed_class_space 7M 7M 1024M 0.70%
Runtime
os.name Windows 8.1
os.version 6.3
java.version 1.8.0_25
java.home C:\Program Files\Java\jdk1.8.0_25\jre
systemload.average -1.00
processors 8
timestamp/uptime Mon Nov 07 17:08:17 CST 2022/1506s
dump堆，出现对内存溢出时，可以分析哪些对象占用内存多，eclipse插件可以分析
[arthas@10520]$ heapdump
Dumping heap to C:\Users\LIANLI~1\AppData\Local\Temp\heapdump2022-11-07-17-195132433322158585166.hprof ...
Heap dump file created
显示，更新jvm参数
[arthas@22249]$ vmoption PrintGC
KEY VALUE ORIGIN WRITEABLE
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PrintGC false DEFAULT true
[arthas@22249]$ vmoption PrintGC true
Successfully updated the vm option.
NAME BEFORE-VALUE AFTER-VALUE
------------------------------------
PrintGC false true
如果只是退出当前的连接，可以用quit或者exit命令。Attach 到目标进程上的 arthas 还会继续运行，端口会保持开放，下次连接时可以直接连接上。
如果想完全退出 arthas，可以执行stop命令。