java-性能排查工具

性能排查工具：

第三方：arthas使用和原理以及btrace、housemd、greys等性能排查工具、在线gc分析工具（gceasy）

jdk：

jconsole、jvisualvm、jmc

参考：

https://arthas.aliyun.com/doc/

https://www.cnblogs.com/fengzheng/p/7416942.html

https://github.com/oldmanpushcart/greys-anatomy

https://github.com/CSUG/HouseMD

https://gceasy.io/

https://blog.csdn.net/qq_40180411/article/details/103893219

Arthas
1.安装
//下载jar包
sudo curl -O https://arthas.aliyun.com/arthas-boot.jar

//运行jar包
sudo -u tomcat java -jar arthas-boot.jar

2.常用命令
dashboard：jvm实时面板
-i：刷新实时数据间隔时间
-n：刷新实时数据的次数

ID: Java级别的线程ID，注意这个ID不能跟jstack中的nativeID一一对应。

NAME: 线程名

GROUP: 线程组名

PRIORITY: 线程优先级, 1~10之间的数字，越大表示优先级越高

STATE: 线程的状态

RUNNABLE 线程运行中或I/O等待
BLOCKED 线程在等待monitor锁(synchronized关键字)
TIMED_WAITING 线程在等待唤醒，但设置了时限
WAITING 线程在无限等待唤醒
CPU%: 线程的cpu使用率。比如采样间隔1000ms，某个线程的增量cpu时间为100ms，则cpu使用率=100/1000=10%

DELTA_TIME: 上次采样之后线程运行增量CPU时间，数据格式为秒

TIME: 线程运行总CPU时间，数据格式为分:秒

INTERRUPTED: 线程当前的中断位状态

DAEMON: 是否是daemon线程

heap:堆
nonheap:方法区（类信息，常量（常量池），静态变量）
metaspace：类的元数据存储
thead：线程信息
-n：打印n个耗时最多的线程
-b：打印阻塞其他线程的线程
sc（search-class）：查找类 可以通配符找到全限定名
monitor：方法耗时监控
-c：统计周期（默认120s）

watch：查看出入参数
-n：执行次数

3.原理
Instrument和Attach API
Jdk5增加了一个包java.lang.instrument，提供了对Jvm底层组件的访问能力，Instrument要求在运行前利用命令行参数或者系统参数设置代理类，VM启动完成之后（绝大多数类加载前）初始化。

开发基于instrument的应用，需要这么几个步骤：

编写premain函数
jar文件打包，制定Premain-Class
使用-javaagent参数启动

jdk5只有在main运行之前进行访问

Jdk6以后，针对这点进行了改进，开发者可以在main函数执行之后再启动自己的Instrument应用，入口是agentmain函数。arthas就是通过这个实现的。

之后就可以通过addTransformer，retransformClasses，redefineClasses等方式对字节码进行增强和热替换了。

ASM

ASM是一个Java字节码操作框架，用来动态生成class或者增强class，cglib的底层就是它，arthas也是通过它实现对class的增强的。通过AOP实现

cglib ： ASM框架对字节码文件进行修改，主要适用于类
jdk动态代理 ：使用反射生成一个代理接口的匿名类，主要适用于接口的实现类。（因为生成的代理类继承了proxy.java）

JPDA
https://juejin.cn/post/6844903608522113038

JVMTI又是在JPDA（Java Platform Debugger Architecture）之下的三层架构之一，JVMTI（JVM Tool Interface）、JDWP（Java Debug Wire Protocol）、JDI（Java Debug Interface）

IDEA的debug也就是使用jpda架构的功能来实现的

agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8080，其实就是加载了jdwp的lib，开启了调试端口，然后就可以通过JDI接口进行交互调试。
Demo

https://github.com/dengshiwei/asm-module

package Demo;

import jdk.internal.org.objectweb.asm.*;
import jdk.internal.org.objectweb.asm.commons.AdviceAdapter;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;

public class CostTime {

    public static void main(String[] args) {
        redefinePersonClass();
    }

    private static void redefinePersonClass() {
        String className = "Demo.AsmDemo";
        try {
            InputStream inputStream = new FileInputStream("C:\\Users\\fangpengx.zhou\\Desktop\\test\\out\\production\\test\\Demo\\AsmDemo.class");
            // 1. 创建 ClassReader 读入 .class 文件到内存中
            ClassReader reader = new ClassReader(inputStream);
            // 2. 创建 ClassWriter 对象，将操作之后的字节码的字节数组回写
            ClassWriter writer = new ClassWriter(reader, ClassWriter.COMPUTE_MAXS);
            // 3. 创建自定义的 ClassVisitor 对象
            ClassVisitor change = new ChangeVisitor(writer);
            // 4. 将 ClassVisitor 对象传入 ClassReader 中
            reader.accept(change, ClassReader.EXPAND_FRAMES);

            Class clazz = new MyClassLoader().defineClasses(className, writer.toByteArray());
            Object personObj = clazz.newInstance();
            Method nameMethod = clazz.getDeclaredMethod("printHelloWorld", null);
            nameMethod.invoke(personObj, null);
            // 获取修改后的 class 文件对应的字节数组
            System.out.println("Success!");
            byte[] code = writer.toByteArray();
            try {
                // 将二进制流写到本地磁盘上
                FileOutputStream fos = new FileOutputStream("C:\\Users\\fangpengx.zhou\\Desktop\\HelloWorld.class");
                fos.write(code);
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("Failure!");
        }
    }

    static class ChangeVisitor extends ClassVisitor {

        ChangeVisitor(ClassVisitor classVisitor) {
            super(Opcodes.ASM5, classVisitor);
        }

        @Override
        public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
            MethodVisitor methodVisitor = super.visitMethod(access, name, desc, signature, exceptions);
            if (name.equals("<init>")) {
                return methodVisitor;
            }
            return new ChangeAdapter(Opcodes.ASM4, methodVisitor, access, name, desc);
        }
    }

    static class ChangeAdapter extends AdviceAdapter {
        private int startTimeId = -1;

        private String methodName = null;

        ChangeAdapter(int api, MethodVisitor mv, int access, String name, String desc) {
            super(api, mv, access, name, desc);
            methodName = name;
        }

        @Override
        protected void onMethodEnter() {
            super.onMethodEnter();
            startTimeId = newLocal(Type.LONG_TYPE);
            mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J", false);
            mv.visitIntInsn(LSTORE, startTimeId);
        }

        @Override
        protected void onMethodExit(int opcode) {
            super.onMethodExit(opcode);
            int durationId = newLocal(Type.LONG_TYPE);
            mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J", false);
            mv.visitVarInsn(LLOAD, startTimeId);
            mv.visitInsn(LSUB);
            mv.visitVarInsn(LSTORE, durationId);
            mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
            mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
            mv.visitInsn(DUP);
            mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "()V", false);
            mv.visitLdcInsn("The cost time of " + methodName + " is ");
            mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
            mv.visitVarInsn(LLOAD, durationId);
            mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(J)Ljava/lang/StringBuilder;", false);
            mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
            mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
        }
    }

}










//结果
"C:\Program Files\Java\jdk1.8.0_261\bin\java.exe" "-javaagent:C:\Users\fangpengx.zhou\IntelliJ IDEA 2020.1.2\lib\idea_rt.jar=14144:C:\Users\fangpengx.zhou\IntelliJ IDEA 2020.1.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_261\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\rt.jar;C:\Users\fangpengx.zhou\Desktop\test\out\production\test" Demo.CostTime
hello world
The cost time of printHelloWorld is 1001
Success!

Process finished with exit code 0



//反编译
package Demo;

public class AsmDemo {
    public AsmDemo() {
    }

    public void printHelloWorld() {
        long var1 = System.currentTimeMillis();

        try {
            String s = "hello world";
            Thread.sleep(1000L);
            System.out.println(s);
        } catch (Exception var6) {
            var6.printStackTrace();
        }

        long var4 = System.currentTimeMillis() - var1;
        System.out.println("The cost time of printHelloWorld is " + var4);
    }
}









//查看线程信息
package Demo.test;

import java.lang.management.ManagementFactory;
import java.lang.management.MemoryUsage;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;

public class MultiThread {

    public static void main(String[] args){
        //获取java的线程管理MXBean
        ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
        //不需要获取同步的monitor和synchronizer信息，仅获取线程和线程堆栈信息
        ThreadInfo[] threadInfo = threadBean.dumpAllThreads(false, false);
        //遍历线程信息，仅打印线程id和线程名称信息
        for(ThreadInfo info : threadInfo){
            System.out.println(info.getThreadId() + "--" + info.getThreadName() +"--"+ info.getThreadState().name());
        }

       //jvm内存MXbEAN
        MemoryUsage heapMemoryUsage = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
        System.out.println("jvm.heap.init is " + (heapMemoryUsage.getInit()));
        System.out.println("jvm.heap.used is " + (heapMemoryUsage.getUsed()));
        System.out.println("jvm.heap.committed is " + (heapMemoryUsage.getCommitted()));
        System.out.println("jvm.heap.max is " + (heapMemoryUsage.getMax()));
    }

}


//结果
"C:\Program Files\Java\jdk1.8.0_261\bin\java.exe" "-javaagent:C:\Users\fangpengx.zhou\IntelliJ IDEA 2020.1.2\lib\idea_rt.jar=2050:C:\Users\fangpengx.zhou\IntelliJ IDEA 2020.1.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_261\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_261\jre\lib\rt.jar;C:\Users\fangpengx.zhou\Desktop\test\out\production\test" Demo.test.MultiThread
6--Monitor Ctrl-Break--RUNNABLE
5--Attach Listener--RUNNABLE
4--Signal Dispatcher--RUNNABLE
3--Finalizer--WAITING
2--Reference Handler--WAITING
1--main--RUNNABLE
jvm.heap.init is 268435456
jvm.heap.used is 5381192
jvm.heap.committed is 257425408
jvm.heap.max is 3797417984

Process finished with exit code 0


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208