Authas — 開源的java診斷工具

下載安裝

authas是一個(gè)jar包，可以直接下載后運(yùn)行

wget https://alibaba.github.io/arthas/arthas-boot.jar

java -jar arthas-boot.jar

就可以啟動(dòng)起來阿逃。啟動(dòng)后突倍，authas會(huì)自動(dòng)檢測(cè)存在的java進(jìn)程，這時(shí)候需要選擇你想要診斷的進(jìn)程盆昙，回車即可羽历。如下圖所示：

image-20190515215103606.png

如果不知道某個(gè)java進(jìn)程的詳情，可以使用

jps -mlVv
或
ps -ef| grep java

來查看.

image-20190515215504917.png

常用命令

基礎(chǔ)命令

help——查看命令幫助信息
cat——打印文件內(nèi)容淡喜，和linux里的cat命令類似
pwd——返回當(dāng)前的工作目錄秕磷，和linux命令類似
cls——清空當(dāng)前屏幕區(qū)域
session——查看當(dāng)前會(huì)話的信息
reset——重置增強(qiáng)類，將被 Arthas 增強(qiáng)過的類全部還原炼团，Arthas 服務(wù)端關(guān)閉時(shí)會(huì)重置所有增強(qiáng)過的類
version——輸出當(dāng)前目標(biāo) Java 進(jìn)程所加載的 Arthas 版本號(hào)
history——打印命令歷史
quit——退出當(dāng)前 Arthas 客戶端澎嚣，其他 Arthas 客戶端不受影響
shutdown——關(guān)閉 Arthas 服務(wù)端，所有 Arthas 客戶端全部退出
keymap——Arthas快捷鍵列表及自定義快捷鍵

JVM相關(guān)

Dashboard

dashboard
 USAGE:
   dashboard [-b] [-i <value>] [-n <value>]

 SUMMARY:
   Overview of target jvm's thread, memory, gc, vm, tomcat info.

 EXAMPLES:
   dashboard
   dashboard -n 10
   dashboard -i 2000

 WIKI:
   https://alibaba.github.io/arthas/dashboard

 OPTIONS:
 -b, --batch                                   Execute this command in batch mode.
 -i, --interval <value>                        The interval (in ms) between two executions, default is 5000 ms.
 -n, --number-of-execution <value>             The number of times this command will be executed.

image-20190515215857569.png

可以看到瘟芝，這里會(huì)顯示出線程(按照cpu占用百分比倒排)易桃、內(nèi)存(堆空間實(shí)時(shí)情況)、GC情況等數(shù)據(jù)锌俱。

常用的參數(shù)：

-i 400ms 每次執(zhí)行間隔時(shí)間

-n 執(zhí)行多少次dashboard晤郑，不指定的話會(huì)一直刷新

thread

thread命令用來查看當(dāng)前jvm中的線程信息的，如下圖所示：

image-20190515220246248.png

可以看到贸宏，默認(rèn)執(zhí)行thread命令造寝，會(huì)直接打印出當(dāng)前所有的線程。

$ thread
 USAGE:
   thread [-b] [-i <value>] [-n <value>] [id]

 SUMMARY:
   Display thread info, thread stack

 EXAMPLES:
   thread
   thread 51
   thread -n -1
   thread -n 5
   thread -b
   thread -i 2000

 WIKI:
   https://alibaba.github.io/arthas/thread

 OPTIONS:
 -b, --include-blocking-th  Find the thread who is holding a lock that blocks t
 read                       he most number of threads.
 -i, --sample-interval <va  Specify the sampling interval (in ms) when calculat
 lue>                       ing cpu usage.
 -n, --top-n-threads <valu  The number of thread(s) to show, ordered by cpu uti
 e>                         lization, -1 to show all.
 <id>                       Show thread stack

常用參數(shù)：

-b 查看目前block的線程

-i 5000ms 查看在接下來的多長(zhǎng)時(shí)間內(nèi) 統(tǒng)計(jì)cpu利用率

-n 5 查看cpu占用率前5的線程的堆棧信息

<thread_id> 直接跟著線程id，可以看到thread的堆棧信息

如下：

$ thread -n 1
"as-command-execute-daemon" Id=396 cpuUsage=53% RUNNABLE
    at sun.management.ThreadImpl.dumpThreads0(Native Method)
    at sun.management.ThreadImpl.getThreadInfo(ThreadImpl.java:448)
    at com.taobao.arthas.core.command.monitor200.ThreadCommand.processTopBusyThreads(ThreadCommand.java:133)
    at com.taobao.arthas.core.command.monitor200.ThreadCommand.process(ThreadCommand.java:79)
    at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.process(AnnotatedCommandImpl.java:82)
    at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.access$100(AnnotatedCommandImpl.java:18)
    at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:111)
    at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:108)
    at com.taobao.arthas.core.shell.system.impl.ProcessImpl$CommandProcessTask.run(ProcessImpl.java:370)
    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)

    Number of locked synchronizers = 1
    - java.util.concurrent.ThreadPoolExecutor$Worker@21b51d37


Affect(row-cnt:0) cost in 541 ms.

可以看到這里占用cpu最高的一個(gè)線程的棧信息。

jvm

查看當(dāng)前jvm信息

sysprop

查看和修改JVM的系統(tǒng)屬性

sysenv

查看JVM的環(huán)境變量

getstatic

查看類的靜態(tài)屬性

class/classloader相關(guān)

mc

Memory Compiler/內(nèi)存編譯器店茶，編譯.java文件生成.class。

mc /tmp/Test.java

redefine

加載外部的.class文件签赃，redefine jvm已加載的類谷异。

redefine /tmp/Test.class
redefine -c 327a647b /tmp/Test.class /tmp/Test\$Inner.class

sc

Search class

查看jvm中已加載的類，不過直接執(zhí)行sc并沒有太多信息锦聊，如下：

$ sc com.google.common.hash.HashFunction
com.google.common.hash.AbstractHashFunction
com.google.common.hash.HashFunction
com.google.common.hash.MessageDigestHashFunction
Affect(row-cnt:3) cost in 213 ms.

需要加入-d參數(shù)晰绎，如下

$ sc -d com.google.common.hash.HashFunction
 class-info        com.google.common.hash.AbstractHashFunction
 code-source
 name              com.google.common.hash.AbstractHashFunction
 isInterface       false
 isAnnotation      false
 isEnum            false
 isAnonymousClass  false
 isArray           false
 isLocalClass      false
 isMemberClass     false
 isPrimitive       false
 isSynthetic       false
 simple-name       AbstractHashFunction
 modifier          abstract
 annotation        com.google.errorprone.annotations.Immutable
 interfaces        com.google.common.hash.HashFunction
 super-class       +-java.lang.Object
 class-loader      +-com.intellij.util.lang.UrlClassLoader@277050dc
 classLoaderHash   277050dc

 class-info        com.google.common.hash.HashFunction
 code-source
 name              com.google.common.hash.HashFunction
 isInterface       true
 isAnnotation      false
 isEnum            false
 isAnonymousClass  false
 isArray           false
 isLocalClass      false
 isMemberClass     false
 isPrimitive       false
 isSynthetic       false
 simple-name       HashFunction
 modifier          abstract,interface,public
 annotation        com.google.errorprone.annotations.Immutable
 interfaces
 super-class
 class-loader      +-com.intellij.util.lang.UrlClassLoader@277050dc
 classLoaderHash   277050dc

 class-info        com.google.common.hash.MessageDigestHashFunction
 code-source
 name              com.google.common.hash.MessageDigestHashFunction
 isInterface       false
 isAnnotation      false
 isEnum            false
 isAnonymousClass  false
 isArray           false
 isLocalClass      false
 isMemberClass     false
 isPrimitive       false
 isSynthetic       false
 simple-name       MessageDigestHashFunction
 modifier          final
 annotation        com.google.errorprone.annotations.Immutable
 interfaces        java.io.Serializable
 super-class       +-com.google.common.hash.AbstractHashFunction
                     +-java.lang.Object
 class-loader      +-com.intellij.util.lang.UrlClassLoader@277050dc
 classLoaderHash   277050dc

Affect(row-cnt:3) cost in 102 ms.

可以看到這里有更詳細(xì)的信息。

具體的參數(shù)如下：

$ help sc
 USAGE:
   sc [-d] [-x <value>] [-f] [-h] [-E] class-pattern

 SUMMARY:
   Search all the classes loaded by JVM

 EXAMPLES:
   sc -d org.apache.commons.lang.StringUtils
   sc -d org/apache/commons/lang/StringUtils
   sc -d *StringUtils
   sc -d -f org.apache.commons.lang.StringUtils
   sc -E org\\.apache\\.commons\\.lang\\.StringUtils

 WIKI:
   https://alibaba.github.io/arthas/sc

 OPTIONS:
 -d, --details                                                       Display the details of class
 -x, --expand <value>                                                Expand level of object (0 by default)
 -f, --field                                                         Display all the member variables
 -h, --help                                                          this help
 -E, --regex                                                         Enable regular expression to match (wildcard matching by default)
 <class-pattern>                                                     Class name pattern, use either '.' or '/' as separator

sm

search method

$ sm xx.xxx.xx.xx.xxx.xx.CouponService
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl <init>()V
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl matchCouponOnShopIds(Ljava/lang/Long;Ljava/util/List;)Ljava/util/Map;
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 <init>()V
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 CGLIB$matchCouponOnShopIds$0(Ljava/lang/Long;Ljava/util/List;)Ljava/util/Map;
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 CGLIB$SET_THREAD_CALLBACKS([Lcom/google/inject/internal/cglib/pr$ oxy/$Callback;)V
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 CGLIB$SET_STATIC_CALLBACKS([Lcom/google/inject/internal/cglib/proxy/$Callback;)V
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 CGLIB$STATICHOOK35()V
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 CGLIB$BIND_CALLBACKS(Ljava/lang/Object;)V
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 CGLIB$findMethodProxy(Lcom/google/inject/internal/cglib/core/$Signature;)Lcom/google/inject/internal/cglib/proxy/$MethodProxy;
xx.xxx.xx.xx.xxx.xx.CouponServiceImpl$$EnhancerByGuice$$9b64c3b8 matchCouponOnShopIds(Ljava/lang/Long;Ljava/util/List;)Ljava/util/Map;
xx.xxx.xx.xx.xxx.xx.CouponService matchCouponOnShopIds(Ljava/lang/Long;Ljava/util/List;)Ljava/util/Map;
com.sun.proxy.$Proxy197 <init>(Ljava/lang/reflect/InvocationHandler;)V
com.sun.proxy.$Proxy197 matchCouponOnShopIds(Ljava/lang/Long;Ljava/util/List;)Ljava/util/Map;
com.sun.proxy.$Proxy197 equals(Ljava/lang/Object;)Z
com.sun.proxy.$Proxy197 toString()Ljava/lang/String;
com.sun.proxy.$Proxy197 hashCode()I
Affect(row-cnt:16) cost in 53 ms.

可以看到括丁，通過sm命令可以查到對(duì)應(yīng)類的所有方法

通過加入-d參數(shù)可以獲取method的信息信息

$ sm xx.xxx.xx.xx.xxx.xx.CouponService -d
 declaring-class   xx.xxx.xx.xx.xxx.xx.CouponServiceImpl
 constructor-name  <init>
 modifier          public
 annotation
 parameters
 exceptions

 declaring-class  xx.xxx.xx.xx.xxx.xx.CouponServiceImpl
 method-name      matchCouponOnShopIds
 modifier         public
 annotation
 parameters       java.lang.Long
                  java.util.List
 return           java.util.Map
 exceptions       xx.xxx.xx.xx.xxx.xx.ServiceException
 
 ...

sh

jad

反編譯代碼，如下

$ jad com.google.common.hash.HashFunction

ClassLoader:
+-com.intellij.util.lang.UrlClassLoader@277050dc

Location:


/*
 * Decompiled with CFR 0_132.
 *
 * Could not load the following classes:
 *  com.google.common.hash.Funnel
 *  com.google.common.hash.HashCode
 *  com.google.common.hash.Hasher
 *  com.google.errorprone.annotations.Immutable
 */
package com.google.common.hash;

import com.google.common.hash.Funnel;
import com.google.common.hash.HashCode;
import com.google.common.hash.Hasher;
import com.google.errorprone.annotations.Immutable;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;

@Immutable
public interface HashFunction {
    public int bits();

    public HashCode hashLong(long var1);

    public HashCode hashInt(int var1);

    public <T> HashCode hashObject(T var1, Funnel<? super T> var2);

    public HashCode hashUnencodedChars(CharSequence var1);

    public HashCode hashString(CharSequence var1, Charset var2);

    public HashCode hashBytes(ByteBuffer var1);

    public HashCode hashBytes(byte[] var1, int var2, int var3);

    public HashCode hashBytes(byte[] var1);

    public Hasher newHasher();

    public Hasher newHasher(int var1);
}

Affect(row-cnt:1) cost in 1730 ms.

classloader

查看classloader的繼承樹伶选，urls史飞，類加載信息

image-20190520141344323.png

查看其參數(shù)如下

$ help classloader
 USAGE:
   classloader [-a] [-c <value>] [-h] [-i] [-l] [--load <value>] [-r <value>] [-t]

 SUMMARY:
   Show classloader info

 EXAMPLES:
   classloader
   classloader -t
   classloader -l
   classloader -c 327a647b
   classloader -c 327a647b -r META-INF/MANIFEST.MF
   classloader -a
   classloader -a -c 327a647b
   classloader -c 659e0bfd --load demo.MathGame

 WIKI:
   https://alibaba.github.io/arthas/classloader

 OPTIONS:
 -a, --all                                                           Display all classes loaded by ClassLoader
 -c, --classloader <value>                                           The hash code of the special ClassLoader
 -h, --help                                                          this help
 -i, --include-reflection-classloader                                Include sun.reflect.DelegatingClassLoader
 -l, --list-classloader                                              Display statistics info by classloader instance
     --load <value>                                                  Use ClassLoader to load class, won't work without -c specified
 -r, --resource <value>                                              Use ClassLoader to find resources, won't work without -c specified
 -t, --tree                                                          Display ClassLoader tree

-t : 把classloader的樹打印出來，也會(huì)打印出來粗略的hashcode

-l : 根據(jù)classloader實(shí)例的個(gè)數(shù)來打印classloader仰税，會(huì)打印出來hashcode

-c : 用classloader對(duì)應(yīng)的hashcode 來查看對(duì)應(yīng)的jar urls

查看classloader tree信息

$ classloader -t
+-BootstrapClassLoader
+-sun.misc.Launcher$ExtClassLoader@6379eb
  +-com.taobao.arthas.agent.ArthasClassloader@5ab570f5
  +-sun.misc.Launcher$AppClassLoader@18b4aac2
    +-com.alibaba.fastjson.util.ASMClassLoader@34c3f8d2
    +-com.alibaba.fastjson.util.ASMClassLoader@463b35ac
    +-com.alibaba.jvm.sandbox.agent.SandboxClassLoader@567d299b
    +-ModuleClassLoader[crc32=3750510264;file=/data/.ewatch/ewatch-install/sandbox/lib/../module/sandbox-mgr-module.jar;]
    +-ModuleClassLoader[crc32=2030492332;file=/data/.ewatch/ewatch-install/sandbox/ewatch/ewatch-agent-jar-with-dependencies.jar;]
    +-com.alibaba.jvm.sandbox.core.classloader.ProviderClassLoader@42f93a98
Affect(row-cnt:10) cost in 20 ms.

查看URLClassLoader實(shí)際的urls

$ classloader -c 5ab570f5
file:/root/.arthas/lib/3.1.1/arthas/arthas-core.jar

Affect(row-cnt:1790) cost in 19 ms.

使用ClassLoader去查找resource

$ classloader -c 3d4eac69  -r META-INF/MANIFEST.MF
 jar:file:/System/Library/Java/Extensions/MRJToolkit.jar!/META-INF/MANIFEST.MF
 jar:file:/private/tmp/arthas-demo.jar!/META-INF/MANIFEST.MF
 jar:file:/Users/hengyunabc/.arthas/lib/3.0.5/arthas/arthas-agent.jar!/META-INF/MANIFEST.MF

也可以嘗試查找類的class文件：

$ classloader -c 1b6d3586 -r java/lang/String.class
 jar:file:/Library/Java/JavaVirtualMachines/jdk1.8.0_60.jdk/Contents/Home/jre/lib/rt.jar!/java/lang/String.class

使用ClassLoader去加載類

$ classloader -c 3d4eac69 --load demo.MathGame
load class success.
 class-info        demo.MathGame
 code-source       /private/tmp/arthas-demo.jar
 name              demo.MathGame
 isInterface       false
 isAnnotation      false
 isEnum            false
 isAnonymousClass  false
 isArray           false
 isLocalClass      false
 isMemberClass     false
 isPrimitive       false
 isSynthetic       false
 simple-name       MathGame
 modifier          public
 annotation
 interfaces
 super-class       +-java.lang.Object
 class-loader      +-sun.misc.Launcher$AppClassLoader@3d4eac69
                     +-sun.misc.Launcher$ExtClassLoader@66350f69
 classLoaderHash   3d4eac69

monitor/watch/trace相關(guān)

monitor

對(duì)匹配 class-pattern／method-pattern的類构资、方法的調(diào)用進(jìn)行監(jiān)控。

monitor 命令是一個(gè)非實(shí)時(shí)返回命令.

實(shí)時(shí)返回命令是輸入之后立即返回陨簇，而非實(shí)時(shí)返回的命令吐绵，則是不斷的等待目標(biāo) Java 進(jìn)程返回信息，直到用戶輸入 Ctrl+C 為止河绽。

服務(wù)端是以任務(wù)的形式在后臺(tái)跑任務(wù)己单，植入的代碼隨著任務(wù)的中止而不會(huì)被執(zhí)行，所以任務(wù)關(guān)閉后耙饰，不會(huì)對(duì)原有性能產(chǎn)生太大影響纹笼，而且原則上，任何Arthas命令不會(huì)引起原有業(yè)務(wù)邏輯的改變苟跪。

監(jiān)控的維度說明

$ monitor -c 5 demo.MathGame primeFactors
Press Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 94 ms.
 timestamp            class          method        total  success  fail  avg-rt(ms)  fail-rate
-----------------------------------------------------------------------------------------------
 2018-12-03 19:06:38  demo.MathGame  primeFactors  5      1        4     1.15        80.00%
 
 timestamp            class          method        total  success  fail  avg-rt(ms)  fail-rate
-----------------------------------------------------------------------------------------------
 2018-12-03 19:06:43  demo.MathGame  primeFactors  5      3        2     42.29       40.00%
 
 timestamp            class          method        total  success  fail  avg-rt(ms)  fail-rate
-----------------------------------------------------------------------------------------------
 2018-12-03 19:06:48  demo.MathGame  primeFactors  5      3        2     67.92       40.00%
 
 timestamp            class          method        total  success  fail  avg-rt(ms)  fail-rate
-----------------------------------------------------------------------------------------------
 2018-12-03 19:06:53  demo.MathGame  primeFactors  5      2        3     0.25        60.00%
 
 timestamp            class          method        total  success  fail  avg-rt(ms)  fail-rate
-----------------------------------------------------------------------------------------------
 2018-12-03 19:06:58  demo.MathGame  primeFactors  1      1        0     0.45        0.00%
 
 timestamp            class          method        total  success  fail  avg-rt(ms)  fail-rate
-----------------------------------------------------------------------------------------------
 2018-12-03 19:07:03  demo.MathGame  primeFactors  2      2        0     3182.72     0.00%

watch

查看函數(shù)的參數(shù)、返回值件已、異常信息笋额，如果有請(qǐng)求觸發(fā)，就回打印對(duì)應(yīng)的數(shù)據(jù)篷扩。用法如下

$ help watch
 USAGE:
   watch [-b] [-e] [-x <value>] [-f] [-h] [-n <value>] [-E] [-M <value>] [-s] class-pattern method-pattern express [condition-express]

 SUMMARY:
   Display the input/output parameter, return object, and thrown exception of specified method invocation
   The express may be one of the following expression (evaluated dynamically):
           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
 Examples:
   watch -b org.apache.commons.lang.StringUtils isBlank params
   watch -f org.apache.commons.lang.StringUtils isBlank returnObj
   watch org.apache.commons.lang.StringUtils isBlank '{params, target, returnObj}' -x 2
   watch -bf *StringUtils isBlank params
   watch *StringUtils isBlank params[0]
   watch *StringUtils isBlank params[0] params[0].length==1
   watch *StringUtils isBlank params '#cost>100'
   watch -E -b org\.apache\.commons\.lang\.StringUtils isBlank params[0]

 OPTIONS:
 -b, --before                                                        Watch before invocation
 -e, --exception                                                     Watch after throw exception
 -x, --expand <value>                                                Expand level of object (1 by default)
 -f, --finish                                                        Watch after invocation, enable by default
 -h, --help                                                          this help
 -n, --limits <value>                                                Threshold of execution times
 -E, --regex                                                         Enable regular expression to match (wildcard matching by default)
 -M, --sizeLimit <value>                                             Upper size limit in bytes for the result (10 * 1024 * 1024 by default)
 -s, --success                                                       Watch after successful invocation
 <class-pattern>                                                     The full qualified class name you want to watch
 <method-pattern>                                                    The method name you want to watch
 <express>                                                           the content you want to watch, written by ognl.
                                                                     Examples:
                                                                       params
                                                                       params[0]
                                                                       'params[0]+params[1]'
                                                                       '{params[0], target, returnObj}'
                                                                       returnObj
                                                                       throwExp
                                                                       target
                                                                       clazz
                                                                       method

 <condition-express>                                                 Conditional expression in ognl style, for example:
                                                                       TRUE  : 1==1
                                                                       TRUE  : true
                                                                       FALSE : false
                                                                       TRUE  : 'params.length>=0'
                                                                       FALSE : 1==2

具體執(zhí)行如下（查看請(qǐng)求參數(shù)）：

$ watch xxx.xxx.xxx.xxx.BerlinService view params

Press Q or Ctrl+C to abort.
Affect(class-cnt:3 , method-cnt:3) cost in 393 ms.
ts=2019-05-17 14:43:36; [cost=37.391098ms] result=@Object[][
    @BerlinRequest[BerlinRequest(activityId=RC_12, userId=309314913, latitude=31.224360913038254, longitude=121.55064392834902, userAgent=Rajax/1 MI_MAX/helium Android/7.0 Display/NRD90M me/8.16.1 Channel/tengxun ID/e75ef7ec-4069-38ee-83c4-51fb7067f3e1; KERNEL_VERSION:3.10.84-perf-gd39c060 API_Level:24 Hardware: Mozilla/5.0 (Linux; Android 7.0; MI MAX Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/64.0.3282.137 Mobile Safari/537.36 AliApp(ELMC/8.16.1) TTID/offical WindVane/8.5.0,UT4Aplus/0.2.16, deviceId=null, limit=8, offset=0)],
]
ts=2019-05-17 14:43:36; [cost=46.358372ms] result=@Object[][
    @BerlinRequest[BerlinRequest(activityId=RC_12, userId=309314913, latitude=31.224360913038254, longitude=121.55064392834902, userAgent=Rajax/1 MI_MAX/helium Android/7.0 Display/NRD90M me/8.16.1 Channel/tengxun ID/e75ef7ec-4069-38ee-83c4-51fb7067f3e1; KERNEL_VERSION:3.10.84-perf-gd39c060 API_Level:24 Hardware: Mozilla/5.0 (Linux; Android 7.0; MI MAX Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/64.0.3282.137 Mobile Safari/537.36 AliApp(ELMC/8.16.1) TTID/offical WindVane/8.5.0,UT4Aplus/0.2.16, deviceId=null, limit=8, offset=0)],
]

查看請(qǐng)求參數(shù)及相應(yīng)

$ watch xx.xxx.xx.xx.xxx.xx.BerlinService view '{params[0], returnObj}'

Press Q or Ctrl+C to abort.
Affect(class-cnt:3 , method-cnt:3) cost in 416 ms.
ts=2019-05-17 14:52:38; [cost=33.968815ms] result=@ArrayList[
    @BerlinRequest[BerlinRequest(activityId=RC_12, userId=117043063, latitude=22.682775497436523, longitude=114.04010772705078, userAgent=Rajax/1 Apple/iPhone9,2 iOS/12.2 me/8.16.3 ID/6E92FDB8-FF9F-4F11-BC1A-490E67B39047; IsJailbroken/0 ASI/30F47DE7-0DE5-488E-A479-C94EB9284301 Mozilla/5.0 (iPhone; CPUiPhone OS 12_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 AliApp(ELMC/8.16.3) UT4Aplus/0.0.4 WindVane/8.5.0 1242x2208 WK, deviceId=null, limit=8, offset=0)],
   @BerlinCommonResponse[xx.xxx.xx.xx.xxx.xx.BerlinCommonResponse@4c5df030],
]

可以看到兄猩，包含了請(qǐng)求及相應(yīng)數(shù)據(jù)、整體cost-time,不過需要注意的是鉴未，這里并沒有打印出所有詳細(xì)數(shù)據(jù)厦滤。如果需要打印所有數(shù)據(jù)，加入-x參數(shù)表示遍歷深度歼狼，可以調(diào)整來打印具體的參數(shù)和結(jié)果內(nèi)容掏导。默認(rèn)-x 的深度為1，可以指定 2 3 等,如下：

$ watch xx.xxx.xx.xx.xxx.xx.BerlinService view '{params, returnObj}' -x 2
ts=2019-05-20 11:12:57; [cost=41.677987ms] result=@ArrayList[
    @Object[][
        @BerlinRequest[BerlinRequest(activityId=RC_12, userId=840800602, latitude=36.042474, longitude=103.849928, userAgent=Mozilla/5.0 (Linux; U; Android 8.1.0; zh-CN; DUB-AL00 Build/HUAWEIDUB-AL00) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/57.0.2987.108 UCBrowser/11.8.8.968 UWS/2.13.2.74 Mobile Safari/537.36 UCBS/2.13.2.74_190419112332 NebulaSDK/1.8.100112 Nebula AlipayDefined(nt:4G,ws:360|0|2.0) AliApp(AP/10.1.62.5549) AlipayClient/10.1.62.5549 Language/zh-Hans useStatusBar/true isConcaveScreen/true, deviceId=null, limit=8, offset=0)],
    ],
    @BerlinCommonResponse[
        code=@String[200],
        message=@String[成功],
        data=@ArrayList[isEmpty=false;size=7],
    ],
]

如過需要按照耗時(shí)進(jìn)行過濾羽峰，需要加入： '#cost>200' 代表耗時(shí)超過200ms的才會(huì)打印出來趟咆。

watch/stack/trace這個(gè)三個(gè)命令都支持#cost

trace

方法內(nèi)部調(diào)用路徑添瓷，并輸出方法路徑上的每個(gè)節(jié)點(diǎn)上耗時(shí)

查看help

$ help trace
 USAGE:
   trace [-h] [-j] [-n <value>] [-p <value>] [-E] class-pattern method-pattern [condition-express]

 SUMMARY:
   Trace the execution time of specified method invocation.
                                                      FALSE : false
                                                      TRUE  : 'params.length>=0'
                                                      FALSE : 1==2

   The express may be one of the following expression (evaluated dynamically):
           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
 EXAMPLES:
   trace org.apache.commons.lang.StringUtils isBlank
   trace *StringUtils isBlank
   trace *StringUtils isBlank params[0].length==1
   trace *StringUtils isBlank '#cost>100'
   trace -E org\\.apache\\.commons\\.lang\\.StringUtils isBlank
   trace -E com.test.ClassA|org.test.ClassB method1|method2|method3

 WIKI:
   https://alibaba.github.io/arthas/trace

 OPTIONS:
 -h, --help                                         this help
 -j, --jdkMethodSkip                                skip jdk method trace
 -n, --limits <value>                               Threshold of execution times
 -p, --path <value>                                 path tracing pattern
 -E, --regex                                        Enable regular expression to match (wildcard matching by default)
 <class-pattern>                                    Class name pattern, use either '.' or '/' as separator
 <method-pattern>                                   Method name pattern
 <condition-express>                                Conditional expression in ognl style, for example:
                                                      TRUE  : 1==1
                                                      TRUE  : true

平時(shí)主要使用-j (忽略jdk method trace)、'#cost>10'(過濾耗時(shí)時(shí)間) -n (執(zhí)行次數(shù))

$ trace xx.xxx.xx.xx.xxx.xx.QueryAction queryByReq  -j '#cost>5' -n 5

Press Q or Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 781 ms.
`---ts=2019-05-20 15:27:10;thread_name=thread-272;id=1fb;is_daemon=false;priority=5;TCCL=sun.misc.Launcher$AppClassLoader@18b4aac2
    `---[12.250248ms] xx.xxx.xx.xx.xxx.xx.QueryAction:queryByReq()
    ...
    ...

stack

輸出當(dāng)前方法被調(diào)用的調(diào)用路徑

很多時(shí)候我們都知道一個(gè)方法被執(zhí)行值纱，但這個(gè)方法被執(zhí)行的路徑非常多鳞贷，或者你根本就不知道這個(gè)方法是從那里被執(zhí)行了，此時(shí)你需要的是 stack 命令虐唠。

主要使用-n 命令搀愧，用于控制執(zhí)行次數(shù)

stack xx.xxx.xx.xx.xxx.xx.QueryAction queryByReq -n 1

tt

先看個(gè)例子

$ tt -t xx.xxx.xx.xx.xxx.xx.QueryAction queryByReq -n 5
Press Q or Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 995 ms.
 IND  TIMESTAMP   COST(  IS-  IS  OBJECT    CLASS             METHOD
 EX               ms)    RET  -E
                              XP
--------------------------------------------------------------------------------
 100  2019-05-20  17.52  tru  fa  0x7df629  QueryValidSkuAct  queryValidSkuActi
 5     15:41:29   694    e    ls  87        ivityAction       vityByReq
                              e
 100  2019-05-20  10.26  tru  fa  0x4bb52c  QueryValidSkuAct  queryValidSkuActi
 6     15:41:29   7017   e    ls  96        ivityAction       vityByReq
                              e
 100  2019-05-20  19.80  tru  fa  0x20d351  QueryValidSkuAct  queryValidSkuActi
 7     15:41:29   7279   e    ls  d3        ivityAction       vityByReq
                              e
 100  2019-05-20  19.84  tru  fa  0x286366  QueryValidSkuAct  queryValidSkuActi
 8     15:41:29   4526   e    ls  b4        ivityAction       vityByReq
                              e
 100  2019-05-20  19.91  tru  fa  0x31297b  QueryValidSkuAct  queryValidSkuActi
 9     15:41:29   0582   e    ls  01        ivityAction       vityByReq
                              e
Command execution times exceed limit: 5, so command will exit. You can set it with -n option.
 101  2019-05-20  19.94  tru  fa  0x7a3c2f  QueryValidSkuAct  queryValidSkuActi
 0     15:41:29   8529   e    ls  c4        ivityAction       vityByReq

• 表格字段說明

-t

tt 命令有很多個(gè)主參數(shù)，-t 就是其中之一撤蟆。這個(gè)參數(shù)的表明希望記錄下類 *Test 的 print 方法的每次執(zhí)行情況奕塑。

-n 3

當(dāng)你執(zhí)行一個(gè)調(diào)用量不高的方法時(shí)可能你還能有足夠的時(shí)間用 CTRL+C 中斷 tt 命令記錄的過程，但如果遇到調(diào)用量非常大的方法家肯，瞬間就能將你的 JVM 內(nèi)存撐爆爵川。

此時(shí)你可以通過 -n 參數(shù)指定你需要記錄的次數(shù)，當(dāng)達(dá)到記錄次數(shù)時(shí) Arthas 會(huì)主動(dòng)中斷tt命令的記錄過程息楔，避免人工操作無法停止的情況寝贡。

檢索調(diào)用記錄

當(dāng)你用 tt 記錄了一大片的時(shí)間片段之后，你希望能從中篩選出自己需要的時(shí)間片段值依，這個(gè)時(shí)候你就需要對(duì)現(xiàn)有記錄進(jìn)行檢索圃泡。

假設(shè)我們有這些記錄

$ tt -l
 INDEX   TIMESTAMP            COST(ms)  IS-RET  IS-EXP   OBJECT         CLASS                          METHOD
-------------------------------------------------------------------------------------------------------------------------------------
 1000    2018-12-04 11:15:38  1.096236  false   true     0x4b67cf4d     MathGame                       primeFactors
 1001    2018-12-04 11:15:39  0.191848  false   true     0x4b67cf4d     MathGame                       primeFactors
 1002    2018-12-04 11:15:40  0.069523  false   true     0x4b67cf4d     MathGame                       primeFactors
 1003    2018-12-04 11:15:41  0.186073  false   true     0x4b67cf4d     MathGame                       primeFactors
 1004    2018-12-04 11:15:42  17.76437  true    false    0x4b67cf4d     MathGame                       primeFactors
                              9
 1005    2018-12-04 11:15:43  0.4776    false   true     0x4b67cf4d     MathGame                       primeFactors
Affect(row-cnt:6) cost in 4 ms.

我需要篩選出 primeFactors 方法的調(diào)用信息

$ tt -s 'method.name=="primeFactors"'
 INDEX   TIMESTAMP            COST(ms)  IS-RET  IS-EXP   OBJECT         CLASS                          METHOD
-------------------------------------------------------------------------------------------------------------------------------------
 1000    2018-12-04 11:15:38  1.096236  false   true     0x4b67cf4d     MathGame                       primeFactors
 1001    2018-12-04 11:15:39  0.191848  false   true     0x4b67cf4d     MathGame                       primeFactors
 1002    2018-12-04 11:15:40  0.069523  false   true     0x4b67cf4d     MathGame                       primeFactors
 1003    2018-12-04 11:15:41  0.186073  false   true     0x4b67cf4d     MathGame                       primeFactors
 1004    2018-12-04 11:15:42  17.76437  true    false    0x4b67cf4d     MathGame                       primeFactors
                              9
 1005    2018-12-04 11:15:43  0.4776    false   true     0x4b67cf4d     MathGame                       primeFactors
Affect(row-cnt:6) cost in 607 ms.

你需要一個(gè) -s 參數(shù)。同樣的愿险，搜索表達(dá)式的核心對(duì)象依舊是 Advice 對(duì)象颇蜡。

查看調(diào)用信息

對(duì)于具體一個(gè)時(shí)間片的信息而言，你可以通過 -i 參數(shù)后邊跟著對(duì)應(yīng)的 INDEX 編號(hào)查看到他的詳細(xì)信息辆亏。

$ tt -i 1003
 INDEX            1003
 GMT-CREATE       2018-12-04 11:15:41
 COST(ms)         0.186073
 OBJECT           0x4b67cf4d
 CLASS            demo.MathGame
 METHOD           primeFactors
 IS-RETURN        false
 IS-EXCEPTION     true
 PARAMETERS[0]    @Integer[-564322413]
 THROW-EXCEPTION  java.lang.IllegalArgumentException: number is: -564322413, need >= 2
                      at demo.MathGame.primeFactors(MathGame.java:46)
                      at demo.MathGame.run(MathGame.java:24)
                      at demo.MathGame.main(MathGame.java:16)
 
Affect(row-cnt:1) cost in 11 ms.

重做一次調(diào)用

當(dāng)你稍稍做了一些調(diào)整之后风秤，你可能需要前端系統(tǒng)重新觸發(fā)一次你的調(diào)用，此時(shí)得求爺爺告奶奶的需要前端配合聯(lián)調(diào)的同學(xué)再次發(fā)起一次調(diào)用扮叨。而有些場(chǎng)景下缤弦，這個(gè)調(diào)用不是這么好觸發(fā)的。

tt 命令由于保存了當(dāng)時(shí)調(diào)用的所有現(xiàn)場(chǎng)信息彻磁，所以我們可以自己主動(dòng)對(duì)一個(gè) INDEX 編號(hào)的時(shí)間片自主發(fā)起一次調(diào)用碍沐，從而解放你的溝通成本狸捅。此時(shí)你需要 -p 參數(shù)。通過 --replay-times 指定 調(diào)用次數(shù)累提，通過 --replay-interval 指定多次調(diào)用間隔(單位ms, 默認(rèn)1000ms)

$ tt -i 1004 -p
 RE-INDEX       1004
 GMT-REPLAY     2018-12-04 11:26:00
 OBJECT         0x4b67cf4d
 CLASS          demo.MathGame
 METHOD         primeFactors
 PARAMETERS[0]  @Integer[946738738]
 IS-RETURN      true
 IS-EXCEPTION   false
 COST(ms)         0.186073
 RETURN-OBJ     @ArrayList[
                    @Integer[2],
                    @Integer[11],
                    @Integer[17],
                    @Integer[2531387],
                ]
Time fragment[1004] successfully replayed.
Affect(row-cnt:1) cost in 14 ms.

你會(huì)發(fā)現(xiàn)結(jié)果雖然一樣尘喝，但調(diào)用的路徑發(fā)生了變化，有原來的程序發(fā)起變成了 Arthas 自己的內(nèi)部線程發(fā)起的調(diào)用了斋陪。

• 需要強(qiáng)調(diào)的點(diǎn)

  1. ThreadLocal 信息丟失

     很多框架偷偷的將一些環(huán)境變量信息塞到了發(fā)起調(diào)用線程的 ThreadLocal 中朽褪，由于調(diào)用線程發(fā)生了變化，這些 ThreadLocal 線程信息無法通過 Arthas 保存无虚，所以這些信息將會(huì)丟失缔赠。

     一些常見的 CASE 比如：鷹眼的 TraceId 等。

  2. 引用的對(duì)象

     需要強(qiáng)調(diào)的是骑科，tt 命令是將當(dāng)前環(huán)境的對(duì)象引用保存起來，但僅僅也只能保存一個(gè)引用而已构拳。如果方法內(nèi)部對(duì)入?yún)⑦M(jìn)行了變更咆爽，或者返回的對(duì)象經(jīng)過了后續(xù)的處理，那么在 tt 查看的時(shí)候?qū)o法看到當(dāng)時(shí)最準(zhǔn)確的值置森。這也是為什么 watch 命令存在的意義斗埂。