VisualVM

Java定时任务Timer调度器【二】 多线程源码分析(图文版)

点点圈 提交于 2020-01-07 13:04:32
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 上一节通过一个小例子分析了Timer运行过程,牵涉的执行线程虽然只有两个,但实际场景会比上面复杂一些。 首先通过一张简单类图(只列出简单的依赖关系)看一下Timer暴露的接口。 为了演示Timer所暴露的接口,下面举一个极端的例子(每一个接口方法面向单独的执行线程),照样以闹钟为例( 源码只列出关键部分,下同 )。 public class ScheduleDemo { public static void main(String[] args) throws Exception { AlarmTask alarm1 = new AlarmTask("闹钟1"); AlarmTask alarm2 = new AlarmTask("闹钟2"); new Thread("线程1"){ public void run() { log.info("["+Thread.currentThread().getName()+"]调度闹钟1"); timer.schedule(alarm1,delay,period); } }.start(); new Thread("线程2"){ public void run() { log.info("["+Thread.currentThread().getName()+"

VisualVM unable to connect remote tomcat in docker with RMI

∥☆過路亽.° 提交于 2020-01-04 14:04:09
问题 I am runing tomcat in a docker container on a remote machine. Now I want to use VisualVM to connect. My docker start command: docker run -d --name tomcat -p 26000:8080 -p 9090:9090 -p 9091:9091 -v /data/docker/tomcat/webapps:/data/tomcat/webapps -v /data/docker/tomcat/logs:/data/tomcat/logs -e CATALINA_OPTS="-Xms2048M -Xmx2048M -XX:MaxPermSize=256M -Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.port=9090 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management

VisualVM unable to connect remote tomcat in docker with RMI

自作多情 提交于 2020-01-04 14:03:21
问题 I am runing tomcat in a docker container on a remote machine. Now I want to use VisualVM to connect. My docker start command: docker run -d --name tomcat -p 26000:8080 -p 9090:9090 -p 9091:9091 -v /data/docker/tomcat/webapps:/data/tomcat/webapps -v /data/docker/tomcat/logs:/data/tomcat/logs -e CATALINA_OPTS="-Xms2048M -Xmx2048M -XX:MaxPermSize=256M -Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.port=9090 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management

VisualVM profiling hangs while instrumenting classes

拥有回忆 提交于 2020-01-04 05:56:46
问题 I have a strange behavior while trying to profile a Java Application with VisualVm. Hostsystem = SUSE Linux Enterprise Server 10 Java JDK (same is running VisualVM and Application to profile) = jdk1.8.0_40 64bit Profiling other applications (e.g. Tomcat) running on the host with the same JDK do not have this Problem. Profiling my Application on Windows (running from Eclipse) also works fine. After starting the profiling the log reads the following lines: INFO [org.netbeans.ui.metrics.profiler

java.util.jar.jarfile.init() method takes too long to execute

蹲街弑〆低调 提交于 2020-01-04 04:17:26
问题 Story: I am resolving some performance issues on my Web Application Application background: This Application is written in Java , with Velocity Template Engine , and front-end javaScript using Tomcat9 server. Problem: When i leave the application running, for 10-15 min, the application slows down, So i tried to do VisualVM profiling, and found some traces, that i want to share with you people. UPDATE I debug it more, and find the main reason of redundant calls to Open function in

Performance Cost of Profiling a Web-Application in Production

安稳与你 提交于 2019-12-31 08:13:10
问题 I am attempting to solve performance issues with a large and complex tomcat java web application. The biggest issue at the moment is that, from time to time, the memory usage spikes and the application becomes unresponsive. I've fixed everything I can fix with log profilers and Bayesian analysis of the log files. I'm considering running a profiler on the production tomcat server. A Note to the Reader with Gentle Sensitivities: I understand that some may find the very notion of profiling a

how can java visual VM get connection to eclipse java task

你说的曾经没有我的故事 提交于 2019-12-31 03:54:04
问题 I want to use java VisualVM to monitor the performance of my JAVA APP, but Java VisualVM can not get the detail data of the java task of eclipse. what should I do for this? is any one know? 回答1: Make sure you have -Dcom.sun.management.jmxremote in the vmargs of Eclipse. You can find out whether you have looking in this dialog: Help -> About -> Installation Details -> Configuration. eclipse.vmargs=... shows all the arguments which were passed for the Java VM. If this option is missing, then

深入理解Java虚拟机-如何利用VisualVM对高并发项目进行性能分析

主宰稳场 提交于 2019-12-30 16:13:27
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> Java虚拟机深入理解 系列全部文章更新中... 深入理解Java虚拟机-Java内存区域透彻分析 深入理解Java虚拟机-常用vm参数分析 深入理解Java虚拟机-JVM内存分配与回收策略原理,从此告别JVM内存分配文盲 深入理解Java虚拟机-如何利用JDK自带的命令行工具监控上百万的高并发的虚拟机性能 深入理解Java虚拟机-如何利用VisualVM对高并发项目进行性能分析 深入理解Java虚拟机-你了解GC算法原理吗 前面在学习JVM的知识的时候,一般都需要利用相关参数进行分析,而分析一般都需要用到一些分析的工具,因为一般使用IDEA,而VisualVM对于IDEA也不错,所以就选择VisualVM来分析JVM性能,这篇文章就介绍一下 如何利用VisualVM进行性能分析 ,以及在分析之前需要知道一些 GC优化的原则 , GC优化的目的 ,以及 遇到问题时怎么去解决问题的方法 。 1 为什么需要 开发大型 Java 应用程序的过程中难免遇到内存泄露、性能瓶颈等问题,比如文件、网络、数据库的连接未释放,未优化的算法等。随着应用程序的持续运行,可能会造成整个系统运行效率下降,严重的则会造成系统崩溃。为了找出程序中隐藏的这些问题,在项目开发后期往往会使用性能分析工具来对应用程序的性能进行分析和优化。

Unable to view Visual GC in VisualVM

[亡魂溺海] 提交于 2019-12-29 05:34:09
问题 I am using Java VisualVM on my local windows machine to monitor my remote server(Linux). I am able to get all stats in Bisual VM except " Visual GC ". It shows "Not Supported for this JVM". I have googled it and find that it might be because jstatd is not running and connected. So executed " jstatd -J-Djava.security.policy=/tmp/tools.policy ". It shows a ip " 175.41.139.225 ". I can't understand why it is trying to connect to this ip. It is not the ip of my remote machine nor of my local

How to execute eclipse under java VisualVM

大兔子大兔子 提交于 2019-12-24 17:40:44
问题 I developed couple of plugins specific for my project and I think I have some leackage because my eclipse slow down after long using time, so I want to profile it. I can run eclipse from eclipse (in plugins development mode) and connect it to JVVM, but problem (slow eclipse) occurs after long time of "normal" development, so I want to start my "normal" eclipse and connect to VisualVM. Problem is that eclipse appears in VisualVM as and I can't profile it in any way (I see only number of