ysong2123
@ysong2123

Hi, thanks for the great tool to help us profile our back-end components a lot! i have a quick question about the tool: firstly i use the visualVM jmx remote connection and have a heap-dump file in my local.
the interesting thing is the file is about less than 500 MB. but the heap size is about 8GB in Monitor tab. i think the 8 GB could be the real size in our java component. so why the hpprof file is just 400+MB? and i just also can get the instance size in 400+ level, can't reflect the real memory usage in the runtime, right?

Really appreciated if you great team can help on those concerns.
Thanks,

1170500112
@guozix
I met the problem of "Error Starting VisualVM". It inform me of "You are running VisualVM using JRE" But I have already checked my config in eclipse preference...
Tomas Hurka
@thurka
@guozix Can you please describe in more details, what are you trying to do and what does not work? What version of VisualVM do you use and how is config in eclipse preference involved? Thanks.
1170500112
@guozix
Thank you for your attention. My JDK version is 10.0.1, and eclipse 4.7.3a. I just download the latest version visualvm1.4.2 and visualvm_launcher_u3_eclipse. I have successfully install the integration plugin of visualvm_launcher and checked eclipse preference: Window > Preferences > Run/Debug > Launching > VisualVM Configuration", there's a option "JDK Home", already pointing correctly to my jdk install path. But when I use the visualVM launcher instead of the default launcher of eclipse. It jump out a window: "Error starting VisualVM"and informing "You are running VisualVM using JRE", and inform me to use JDK instead. But I don't know why, I'm actually installed JDK10 and the path is correct. I'm hoping that visualvm work normally in eclipse.
1170500112
@guozix
add:(OS: WIN10) when I double click on visualvm.exe in "\visualvm142\bin", it also jump out the same error window
Tomas Hurka
@thurka
The dialog informing you that "You are running VisualVM using JRE" should also display path to fould JRE. What path it is?
1170500112
@guozix
It's "Location: D\JAVA\jdk10.0.1\jre"
1170500112
@guozix
I remember the time when I was building my java environment, I installed jre in the folder of jdk_home. Is that the reason of my problem?
Tomas Hurka
@thurka
Can you try to start VisualVM from commandline with the following command:
\visualvm142\bin\visualvm.exe --jdkhome D:\JAVA\jdk10.0.1
1170500112
@guozix
Nope. Same dialog again.
Tomas Hurka
@thurka
Ok, we found out that this is caused by your public JRE installation path, which is D:\JAVA\jdk10.0.1\jre. If you choose any other directory like D:\JAVA\jdk10.0.1\jre10 or D:\JAVA\jre10.0.1 VisualVM will start just fine. The only path, which will not work is D:\JAVA\jdk10.0.1\jre. :-) To fix it - please uninstall public JRE 10.0.1 and install it into different directory or do not install it at all.
1170500112
@guozix
Thanks very much! I'll have a try with the method.
Tomas Hurka
@thurka
Ok, let me know the result.
1170500112
@guozix
Aha, it works, finally. Thanks a lot.
Tomas Hurka
@thurka
You are welcome.
Prabhash Rajarathne
@rPrabhash_twitter
Hi All, I'm trying to use VisualVM for a Remote linux host. I connected with the host using "nohup jstatd -p 1099 -J-Djava.security.policy=<(echo 'grant codebase "file:${java.home}/../lib/tools.jar" {permission java.security.AllPermission;};') &" command and unfortunately I can't get the heap dump from the remote machine.
Prabhash Rajarathne
@rPrabhash_twitter
Can someone help me to enable this Heapdump option
Tomas Hurka
@thurka
You need to use JMX to be able to invoke headump remotely. If you need just heap dump and nothing else, I suggest to use jmap on remote linux host to get the heap dump.
t-gmt
@t-gmt
hi there!
have you removed JDBC button from Sampler tab?
Tomas Hurka
@thurka
JDBC button is in Profiler tab. It was never in Sampler tab.
t-gmt
@t-gmt
Thank you @thurka, you're absolutely right! I was confused because Profiler tab was missing and Sampler tab contains exactly the same buttons.
Johan Fabry
@jfabry
Hi all, anybody been able to get visualvm working with Azul Systems' Zulu? It cannot seem to find my installation even though I pass it the options --jdkhome "C:\Program Files\Zulu-Java\"
Tomas Hurka
@thurka
Azul Systems' Zulu should work just fine. Which version of VisualVM do you use? Can you post exact commandline and corresponding error message?

Thank you @thurka, you're absolutely right! I was confused because Profiler tab was missing and Sampler tab contains exactly the same buttons.

Right, Profiler tab is only available for local java applications.

benbw
@AL-Liang

Hi,all.

VisualVM(version:1.4.3 and 1.4.4) worded properly before. However, it does not show applicaitons now and all options under applications are disabled. Some applicaitons are running locally. And No errors were reported.

And I already summited a issue in github. oracle/visualvm#157
arturdeveloper
@arturdeveloper
Hello!
Having problem while trying to run VisualVM on Ubuntu 18.04. Installed from the official repository using Ubuntu Software package manager (some 250MB of downloads). Not able to get past the Licensing Agreement. The "I Agree" and "Exit" buttons at the bottom don't react to clicks. Any ideas?
arturdeveloper
@arturdeveloper
My bad! Had to restart OS to make it work. Problem resolved. Thanks!
ElvinsJ
@caoyifeng007
When I install Tracer-JVM Probes, it says "Some plugins require org.openide.filesystems.combat 8 to be installed". What can I do next?
Jiri Sedlacek
@jisedlac
@caoyifeng007 What is your VisualVM version?
Robert LU
@RobberPhex
Hi, I moved some pages from archive repo. please review this visualvm/visualvm.github.io#2
Jean-Marc Borer
@jmborer
Hi there. Is there a plan to move from Ant to Maven for building the app?
I would be willing to help since I am used to work with the NB platform and Maven since several years now.
So to start experimenting I would like to know which is really the official sources repo on GitHub for the sources of VisualVM?
Jean-Marc Borer
@jmborer
For my information: what is the difference between oracle/visualvm and visualvm/visualvm.github.io?
Jiri Sedlacek
@jisedlac
@jmborer Hello Jean-Marc, thanks for your interest in VisualVM! FYI, visualvm/visualvm.github.io hosts the project web pages, oracle/visualvm contains the tool sources.
Currently we don't plan to switch from Ant to Maven. Can you please file a RFE (https://github.com/oracle/visualvm/issues/new?template=feature_request.md) and describe your use case?
Jean-Marc Borer
@jmborer
@jisedlac Thank you for your answer. I'll do what you suggest. 1) IMHO, with Maven it is much easier to compile and build a Netbeans Platform based application. Ant is more flexible but NB projects are more complexe to understand and therefore to build. 2) When people like me want to build their own app/plugin relying on VisualVM artifacts/modules, it is easier as well 3) publish the Maven artifacts to a repo is just super simple and would avoid the step to use Maven Nb plugins to to publish the artifacts of the Ant project.
My question is: would you be interested if I try to port maybe even in parallel the build from Ant to Maven?
By the way, I was able to re-use some modules from VisualVM (the graphs) in my own NB platform app without using the copied-over modules, but by using the original once instead.
I did not look at the 11.1 based code, but do you still need to copy some module sources from NB platform to VisualVm instead of "depending" on them?
Abhay
@abhaybhegde
Hi, how do i increase the max char limit of SQL query displayed during JDBC profilling?
Tomas Hurka
@thurka
@abhaybhegde The limit is 1024 chars and it is currently not configurable. As a workaround you can change MAX_STRING_LENGTH constant in ProfilerRuntimeCPUand rebuild VisualVM. This way you can increase the max char limit of SQL query.
Jean-Marc Borer
@jmborer
I have updated the readme in my clone to improve the explanation how to generate Maven artefacts. Any interests in integrating this in the master?
Jean-Marc Borer
@jmborer
The documentation to create a plugin is gone. Any chance to restore it?
Zac Policzer
@ZacAttack
Hey folks! Recently upgraded to visvualvm 2.0.1 on OSX. In the past I used to be able to right click an object and copy the objects id down (which I could then feed into an oql query with heap.findObject). I find that in 2.0.1 this functionality is more elusive. Any idea on how to find this?
Jiri Sedlacek
@jisedlac
@ZacAttack The Object ID column is hidden by default. Please enable it by right-clicking the table header. Then you'll have the Copy | Copy Object ID action available in the context menu for the selected instance.
Zac Policzer
@ZacAttack
@jisedlac Thank you so much! That worked!