JVM系列学习(二)：基于JVisualVM的可视化监控

时间  2021-01-05

文章目录

基于JVisualVM的可视化监控

监控本地Tomcat

  1. 路径：\Java\jdk1.8.0_171\bin\jvisualvm.exe
  2. 打开之后更新插件 地址

在这里插入图片描述

监控远程Tomcat

  1. 修改Catalina.sh

    JAVA_OPTS="$JAVA_OPTS -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=port -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.net.preferIPv4Stack=true -Djava.rmi.server.hostname=ip地址"

  2. jar包启动添加参数

    nohup java -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=port -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.net.preferIPv4Stack=true -Djava.rmi.server.hostname=ip地址 -jar XXXX.jar &

  3. VisualVM官方英文文档

  4. VisualVM优秀的中文文档指南

基于Btrace的监控调试

Btrace安装入门

  1. Btrace可以动态地向目标应用程序地字节码注入追踪代码

  2. 安装github地址

  3. 设置环境变量

    • jps -l
    • btrace pid 类名.java
  5. package com.imooc.monitor_tuning.chapter4;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.imooc.monitor_tuning.chapter2.User;

@RestController
@RequestMapping("/ch4")
public class Ch4Controller {
	
	@RequestMapping("/arg1")
	public String arg1(@RequestParam("name")String name) {
		return "hello,"+name;
	}
	
	@RequestMapping("/arg2")
	public User arg2(User user) {
		return user;
	}
	
	@RequestMapping("/constructor")
	public User constructor(User user) {
		return user;
	}
	
	@RequestMapping("/same1")
	public String same(@RequestParam("name")String name) {
		return "hello,"+name;
	}
	@RequestMapping("/same2")
	public String same(@RequestParam("name")String name,@RequestParam("id")int id) {
		return "hello,"+name+","+id;
	}
	
	@RequestMapping("/exception")
	public String exception() {
		try {
			System.out.println("start...");
			System.out.println(1/0);
			System.out.println("end...");
		}catch(Exception e) {
			//
		}
		return "success";
	}

}

Btrace使用详解

拦截方法

  1. 普通方法：@OnMethod(clazz="",method="")

    package com.imooc.monitor_tuning.chapter4;
import com.sun.btrace.AnyType;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.Kind;
import com.sun.btrace.annotations.Location;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;

@BTrace
public class PrintArgSimple {
	
	@OnMethod(
	        clazz="com.imooc.monitor_tuning.chapter4.Ch4Controller",
	        method="arg1",
	        location=@Location(Kind.ENTRY)
	)
	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn, AnyType[] args) {
		BTraceUtils.printArray(args);
		BTraceUtils.println(pcn+","+pmn);
		BTraceUtils.println();
    }
}

  2. 构造方法：@OnMethod(clazz="",method="")

    package com.imooc.monitor_tuning.chapter4;
import com.sun.btrace.AnyType;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;

@BTrace
public class PrintConstructor {
	
	@OnMethod(
	        clazz="com.imooc.monitor_tuning.chapter2.User",
	        method="<init>"
	)
	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn, AnyType[] args) {
		BTraceUtils.println(pcn+","+pmn);
		BTraceUtils.printArray(args);
		BTraceUtils.println();
    }
}

  3. 同名方法：用参数类型来区分

    package com.imooc.monitor_tuning.chapter4;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;

@BTrace
public class PrintSame {
	
	@OnMethod(
	        clazz="com.imooc.monitor_tuning.chapter4.Ch4Controller", //具体到类
	        method="same"//具体到类中的方法
	)
	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn, String name) {
		BTraceUtils.println(pcn+","+pmn + "," + name);
		BTraceUtils.println();
    }
    //或者
    	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn, String name,int id) {//拦截有String,int参数类型的same方法
		BTraceUtils.println(pcn+","+pmn + "," + name);
		BTraceUtils.println();
    }
}

拦截时机

  1. 入口，默认值：Kind.ENTRY

  2. 返回：Kind.RETURN

    package com.imooc.monitor_tuning.chapter4;
import com.sun.btrace.AnyType;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.Kind;
import com.sun.btrace.annotations.Location;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;
import com.sun.btrace.annotations.Return;

@BTrace
public class PrintReturn {
	
	@OnMethod(
	        clazz="com.imooc.monitor_tuning.chapter4.Ch4Controller",
	        method="arg1",
	        location=@Location(Kind.RETURN)
	)
	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn, @Return AnyType result) {
		BTraceUtils.println(pcn+","+pmn + "," + result);
		BTraceUtils.println();
    }
}

  3. 异常：Kind.THROW

    /* * Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the Classpath exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */

package com.imooc.monitor_tuning.chapter4;

import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.Kind;
import com.sun.btrace.annotations.Location;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.Self;
import com.sun.btrace.annotations.TLS;

@BTrace 
public class PrintOnThrow {    
    // store current exception in a thread local
    // variable (@TLS annotation). Note that we can't
    // store it in a global variable!
    @TLS 
    static Throwable currentException;

    // introduce probe into every constructor of java.lang.Throwable
    // class and store "this" in the thread local variable.
    @OnMethod(
        clazz="java.lang.Throwable",
        method="<init>"
    )
    public static void onthrow(@Self Throwable self) {//拦截new Throwable()
        currentException = self;
    }

    @OnMethod(
        clazz="java.lang.Throwable",
        method="<init>"
    )
    public static void onthrow1(@Self Throwable self, String s) {//拦截new Throwable(String msg)
        currentException = self;
    }

    @OnMethod(
        clazz="java.lang.Throwable",
        method="<init>"
    )
    public static void onthrow1(@Self Throwable self, String s, Throwable cause) {//拦截new Throwable(String msg, Throwable cause)
        currentException = self;
    }

    @OnMethod(
        clazz="java.lang.Throwable",
        method="<init>"
    )
    public static void onthrow2(@Self Throwable self, Throwable cause) {//拦截new Throwable(Throwable cause)
        currentException = self;
    }

    // when any constructor of java.lang.Throwable returns
    // print the currentException's stack trace.
    @OnMethod(
        clazz="java.lang.Throwable",
        method="<init>",
        location=@Location(Kind.RETURN)
    )
    public static void onthrowreturn() {
        if (currentException != null) {
        	BTraceUtils.Threads.jstack(currentException);
        	BTraceUtils.println("=====================");
            currentException = null;
        }
    }
}

  4. 行：Kind.LINE 可以定位问题

    package com.imooc.monitor_tuning.chapter4;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.Kind;
import com.sun.btrace.annotations.Location;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;

@BTrace
public class PrintLine {
	
	@OnMethod(
	        clazz="com.imooc.monitor_tuning.chapter4.Ch4Controller",
	        method="exception",
	        [email protected](value=Kind.LINE, line=XX)
	)
	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn, int line) {
		BTraceUtils.println(pcn+","+pmn + "," +line);
		BTraceUtils.println();
    }
}

拦截this，参数，返回值

  1. this:@Self 异常中有举例
  2. 入参：可以用AnyType，也可以用真实类型，同名的用真实类型
  3. 返回：@Return
获取对象的值

  1. 简单类型：直接获取

  2. 复杂类型：反射，类名+属性名

    package com.imooc.monitor_tuning.chapter4;
import java.lang.reflect.Field;

import com.imooc.monitor_tuning.chapter2.User;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.Kind;
import com.sun.btrace.annotations.Location;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;

@BTrace
public class PrintArgComplex {
	//btrace -cp "target/classes路径" pid 类名.java
	@OnMethod(
	        clazz="com.imooc.monitor_tuning.chapter4.Ch4Controller",
	        method="arg2",
	        location=@Location(Kind.ENTRY)
	)
	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn, User user) {
		//print all fields
		BTraceUtils.printFields(user);
		//print one field
		Field filed2 = BTraceUtils.field("com.imooc.monitor_tuning.chapter2.User", "name");
		BTraceUtils.println(BTraceUtils.get(filed2, user));
		BTraceUtils.println(pcn+","+pmn);
		BTraceUtils.println();
    }
}

拦截其他

  1. 正则表达式

    package com.imooc.monitor_tuning.chapter4;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;

@BTrace
public class PrintRegex {
	
	@OnMethod(
	        clazz="com.imooc.monitor_tuning.chapter4.Ch4Controller",
	        method="/.*/"
	)
	public static void anyRead(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
		BTraceUtils.println(pcn+","+pmn);
		BTraceUtils.println();
    }
}

  2. 输出jinfo的参数

    package com.imooc.monitor_tuning.chapter4;

import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;

@BTrace
public class PrintJinfo {
    static {
    	BTraceUtils.println("System Properties:");
    	BTraceUtils.printProperties();
    	BTraceUtils.println("VM Flags:");
    	BTraceUtils.printVmArguments();
    	BTraceUtils.println("OS Enviroment:");
    	BTraceUtils.printEnv();
    	BTraceUtils.exit(0);
    }
}

注意事项

  1. 默认只能本地运行
  2. 生产环境下可以使用，但是被修改的字节码不会被还原
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