Arthas 基础命令实战

朴灿烈づ我的快乐病毒、 2022-09-10 03:25 153阅读 0赞

# 一 点睛 #

> quit/exit 退出当前 Arthas客户端，其他 Arthas喜户端不受影响
> 
> stop/shutdown 关闭 Arthas服务端，所有 Arthas客户端全部退出
> 
> help 查看命令帮助信息
> 
> cat 打印文件内容，和l inux 里的 cat 命令类似
> 
> echo 打印参数，和 linux 里的 echo 命令类似
> 
> grep 匹配查找，和 linux 里的 grep 命令类似
> 
> tee 复制标隹输入到标准输出和指定的文件，和 linux 里的 tee 命令类似
> 
> pwd 返回当前的工作目录，和 linux 命令类似
> 
> cls 清空当前屏幕区域
> 
> session 查看当前会话的信息
> 
> reset 重置增强类，将被 Arthas 增强过的类全部还原, Arthas 服务端关闭时会重置所有增强过的类
> 
> version 输出当前目标 Java 进程所加载的 Arthas 版本号
> 
> history 打印命令历史
> 
> keymap Arthas 快捷键列表及自定义快捷键

# 二 代码 #

package chapter03;
    
    import java.util.ArrayList;
    import java.util.concurrent.TimeUnit;
    
    public class JProfilerTest {
        public static void main(String[] args) {
            while (true){
                ArrayList list = new ArrayList();
                for (int i = 0; i < 500; i++) {
                    Data data = new Data();
                    list.add(data);
                }
                try {
                    TimeUnit.MILLISECONDS.sleep(500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    
    class Data{
        private int size = 10;
        private byte[] buffer = new byte[1024*1024]; // 1 mb
        private String info = "hello,China";
    }

# 三 windows下进入命令界面 #

D:\ProgramFiles\arthas-packaging-3.5.4-bin>jps
    10656 Jps
    12736 Launcher
    2864
    10668 JProfilerTest
    
    D:\ProgramFiles\arthas-packaging-3.5.4-bin>as.bat 10668
    环境变量 JAVA_TOOL_OPTIONS 没有定义
    JAVA_HOME: D:\ProgramFiles\Java\jdk1.8.0_251
    telnet port: 3658
    http port: 8563
    信息: 用提供的模式无法找到文件。
    telnet wasn't found, please google how to install telnet under windows.
    Try to visit http://127.0.0.1:8563 to connecto arthas server.

# 四 实战 #

,---.  ,------. ,--------.,--.  ,--.  ,---.   ,---.
    /  O  \ |  .--. ''--.  .--'|  '--'  | /  O  \ '   .-'
    |  .-.  ||  '--'.'   |  |   |  .--.  ||  .-.  |`.  `-.
    |  | |  ||  |\  \    |  |   |  |  |  ||  | |  |.-'    |
    `--' `--'`--' '--'   `--'   `--'  `--'`--' `--'`-----'
    
    wiki       https://arthas.aliyun.com/doc
    tutorials  https://arthas.aliyun.com/doc/arthas-tutorials.html
    version    3.5.4
    main_class
    pid        10668
    time       2021-09-04 08:53:08
    
    # 帮助命令
    [arthas@10668]$ 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
    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.
    
    # 具体某个命令的帮助
    [arthas@10668]$ reset -h
    USAGE:
       reset [-h] [-E] [class-pattern]
    
    SUMMARY:
       Reset all the enhanced classes
    
    EXAMPLES:
       reset
       reset *List
       reset -E .*List
    
    OPTIONS:
    -h, --help                                       this help
    -E, --regex                                      Enable regular expression to match (wildcard matching by default)
    <class-pattern>                                  Path and classname of Pattern Matching
    
    # cat命令
    [arthas@10668]$ cat E:/JVMDemo3/src/chapter03/Stack.java
    package chapter03;
    
    import java.util.Arrays;
    import java.util.EmptyStackException;
    
    public class Stack {
        private Object[] elements;
        private int size = 0;
        private static final int DEFAULT_INITIAL_CAPACITY = 16;
    
        public Stack() {
            elements = new Object[DEFAULT_INITIAL_CAPACITY];
        }
    
        public void push(Object e) { // 入栈
            ensureCapacity();
            elements[size++] = e;
        }
    
        // 隐式内存泄露代码
        public Object pop() { // 出栈
            if (size == 0)
                throw new EmptyStackException();
            return elements[--size];
        }
    
        private void ensureCapacity() {
            if (elements.length == size)
                elements = Arrays.copyOf(elements, 2 * size + 1);
        }
    }
    
    # pwd 命令
    [arthas@10668]$ pwd
    E:\JVMDemo3
    
    # cls 清屏
    [arthas@10668]$ cls
    
    # session 会话
    [arthas@10668]$ session
    Name        Value
    --------------------------------------------------
    JAVA_PID    10668
    SESSION_ID  5b10ecf4-c0f3-4453-8fbd-42a5c0337e8e
    
    # version 版本号
    [arthas@10668]$ version
    3.5.4
    
    # history 查看历史命令
    [arthas@10668]$ history
        1  help
        2  dashboard -n 2
        3  help
        4  reset -h
        5  pwd
        6  ll
        7  ls
        8  dir
        9  cd src
       10  cat E:\JVMDemo3\src\chapter03\Stack.java
       11  cat E:/JVMDemo3/src/chapter03/Stack.java
       12  pwd
       13  cls
       14  session
       15  version
       16  history
    
    # stop 关闭服务端和所有客户端
    [arthas@10668]$ stop
    Resetting all enhanced classes ...
    Affect(class count: 0 , method count: 0) cost in 2 ms, listenerId: 0
    Arthas Server is going to shutdown...
    [arthas@10668]$ session (5b10ecf4-c0f3-4453-8fbd-42a5c0337e8e) is closed because server is going to shutdown.