VisualVM

**- 1.使用场景 ** 在云主机上进行程序的压力测试，云主机使用端口映射的方式对外开发端口, 所以在局域网中的jconse无法连接到云主机上的java程序。使用了好几办法包括xManager远程启动jconsle,将java程序的jmxremote.port端口映射到路由上等。都行不通，最后只能在云主机所在的局域网中安装一个Windows Server主机，在局域网远程桌面到Windows Server才能使用Jconsole进行远程监控程序运行状态。 关于这个问题的原因可能是：Java RMI中包含了主机名导致的。 **- 2.遇到的问题1： ** 程序和Jconsole在同一个局域网，jconsole无法连接到程序的jmxremote.port端口上 排除配置错误的原因外，你需要修改程序部署的服务器的hostname。 修改方法 (Ubutun) #备份文件 $ cp /etc/hostname /etc/hostname.bk #修改hostname文件 #将127.0.0.1 替换为 主机的局域网IP $ nano /etc/hostname 127.0.0.1 localhost.localdomain localhost **- 3.遇到的问题2：jconsole的使用问题 ** jconsole使用方法 请参考 JConsole使用方法 **- 4

I have a tomcat instance with the JMXRemote parameter configured. The local VisualVM is able to get a sampler on CPU, however, not for Memory. The memory button is grayed out with a summary saying: "Memory sampling: Not available. Cannot connect to target application. Make sure the application is running on a supported JDK 6 or JDK 7" JMXRemote parameter: -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=9086 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false Tomcat JDK version: JDK1.6.0.30 VisualVM version: Version: 1.6.0_30 (Build 1320

I have recently reinstalled Windows and I am using JDK 1.8 u91 with the built-in VisualVM. I have checked my proxy settings to ensure that they are all off, both in Windows proxy settings and within the proxy settings of VisualVM. I have also tried reinstalling JDK, restarting computer, reinstalling Windows. I only have one JDK installed and the classpath is set to the JDK's bin folder in Windows. All features besides CPU and memory profiling work in VisualVM. My application is ran from IntelliJ, but I have also tried running applications regularly from command line and VisualVM cannot connect

I'm using VisualVM from JDK 1.6.0_26 to profile a Java webapp running under Tomcat, but VisualVM often tells me that it doesn't have enough memory to take a snapshot, and to use the -Xmx switch to provide more memory to Netbeans. The problem is, I'm running VisualVM outside of Netbeans, so how can I provide JVM arguments to jvisualvm.exe? Should be able to modify the memory settings in %JDK_HOME%\lib\visualvm\etc\visualvm.conf Xms and Xmx are in the default_options line. or I think this works too: jvisualvm.exe -J-Xmx512m (or whatever amount you need) -J on the .exe command line for onetime

Can someone please explain me the difference between Sleeping , Wait , Park , and Monitor thread states in VisualVM. This is what I have found: Running : thread is still running. Sleeping : thread is sleeping (method yield() was called on the thread object) Wait : thread was blocked by a mutex or a barrier, and is waiting for another thread to release the lock Park : parked threads are suspended until they are given a permit. Unparking a thread is usually done by calling method unpark() on the thread object Monitor : threads are waiting on a condition to become true to resume execution What I

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? 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 open eclipse.ini and search for the line -vmargs . If it's not there, add it at the end: -vmargs -Dcom.sun

I'm investigating an hprof file in VisualVM The server is running JDK 1.4.2_30 and has 1 GB heap with NewSize of 200 Mb. The hprof shows 71% of the heap occupied by 56000 instances of int[] and none of these 56K arrays have references when viewed in VisualVM As per us, this should have been garbage collected if there were "no references". So the questions are: a) is there any way to find out these references? b) Is this an incorrect snapshot - i.e. did the action of taking the heap dump do some sort of GC ? c) Should we be looking at the "retained sizes" objects in VisualVM? As an update - we

I created a heap dump file with hprof using this command: java -agentlib:hprof -cp "..\..\jars\trove.jar;.\bin" com.mysite.MyApp This successfully created the file "java.hprof.txt" which was about 5MB. I then opened up jvisualvm to view this file, and loaded it in. But visualvm appears to be stuck on the loading screen. The screen below has been up for about 10 minutes now. Did I miss a step? Should I have used different options on the command line with hprof? How can I read this heap dump file? VisualVM supports heap dumps in binary HPROF format. It is easier to use VisualVM to create heap