I'm running Minecraft on a headless Linux server with OpenJDK. I've added a bunch too many mods and its lagging (even on my local network) without using too much CPU or memory (e.g. its lagging, but its still got resources it can use). So I'm pretty sure its a mod fault.
To save the hassle of removing/adding mods one by one to see whats causing the error, my research led me to VisualVM where you can profile the java application and see which entities are doing what and with what resources. With any luck it should point out the mod consuming the most resources, and the most ticks.
Given its a headless server, and VisualVM is a window/GUI application, I've successfully managed to get it running and passing the GUI back to my Windows client using X over SSH.
Trouble is now, that its telling me that I need to use JDK and not JRE. Which is fair enough. Except OpenJDK has JDK in its name, rendering all googling futile. I cannot for the life of me, find if JDK is included in OpenJDK, what its named, and where it may be located. The other problem is, most of the troubleshooting guides I find are for Windows, and dont help me find the JDK on linux.
As some background information, I'm running Debian, and I know OpenJDK's JRE is installed here: /usr/lib/jvm/java-7-openjdk-amd64/jre
Can someone tell me please, if JDK is in OpenJDK, or I need to install it as well? If I do need to install it, is there an OpenJDK equivelant for JDK? If its already included, can someone provide some tips on locating it, so I can point VisualVM at it instead of the JRE?
The OpenJDK has a JDK, but there is also a cut down version which is just the JRE. I would use locate javac and if it can't find it, you need to install the JDK.
Related
On my computer (64 bit operating system, x64 based processor) I installed Amazon Correto JDK 11 (for 64 bit) and IntelliJ IDEA. it was working till today without any issues. But now I can not open my Intellij IDEA. In fact it is not even launching.
I checked the environment variables and path reference of Java. It is all set. But when I double click on Intellij IDEA it is showing loading sign for a moment but it is not launching. I tried to run the same by going to it's directory and by using cmd. But still it is not launching. When I try to open the 32-bit version I get an error, but I know it is obvious, because I am using a JDK version for 64 bit. I want to know why my Intellij IDEA is not launching. Even after downloading the appropriate Java version and setting up the path correctly. There were no issues till today. I tried reinstalling my Java and Intellij. Still the issue is there. If anyone can help, please let me know the reason.
You are trying to run 32-bit idea.exe while your default JDK points to 64-bit JDK, hence the problem. Please use idea64.exe instead that will run on the bundled JetBrains Runtime.
In case idea64.exe also fails, please run using idea.bat inside cmd.exe to see if there any errors logged in the console.
Perform the steps from this document if the issue is caused by some plug-in or corrupted options.
I use this solution to have a VNC desktop session with a remote Ubuntu PC https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-vnc-on-ubuntu-16-04
I want to setup monodevelop on this machine. I followed the instructions and am able to run monodevelop and write code, however when I attempt to run it I get "Could not connect to the debugger". I tried various solutions suggesting changing environment variables to force monodevelop to use xterm and it did not work, however I'm not positive I did it correctly as the solution was meant for gnome and the modifications to the command for XFCE were not clear to me. At this point I'd be willing to get paid support, but I'm not even sure where I could find any for my use case. Does anyone have experience getting monodevelop to work on XFCE? If not what is the best environment for getting it going (ideally a way where I could remote in too). I'm very accustomed to the RDP workflow where I can actually troubleshoot on a development server and be very close to the real world environment to get things running, then check-in and deploy. I think there are a lot of platform differences with monodevelop so I really really really want to develop on Ubuntu (remotely).
I am getting following error while running /tmp/jprofiler8/bin/jpenable
No suitable Java Virtual Machine could be found on your system.
The version of the JVM must be at least 1.6 and at most 1.7.
Please define INSTALL4J_JAVA_HOME to point to a suitable JVM.
You can also try to delete the JVM cache file
I have also set INSTALL4J_JAVA_HOME to point to suitable JVM.
Java version on my machine is 1.4.2.
Can anyone please suggest what might be wrong or missing?
Unfortunately you did not mention details about your environment, so I don't know which Linux distribution you use.
There are some options though:
install a current JRE alongside the installer for JProfiler
As you can't install or update Java, you could provide a JRE in a kind of "portable application" setup. Simply unzip the server jre Oracle provides or (if you are not on an x64 architecture) unzip the jdk you also can download from Oracle.
But if the code you want to profile is limited to your pre-installed Java 1.4 you will run into another problem, because as far as I know Java 1.5 is the minimum JProfiler expects
use a different machine for profiling
Unless your code depends heavily on the environment you run it in you can even take a Windows 8.1 machine and profile the code there. Code that is slow is slow on any operating system. Or make use of a different Linux computer.
I home host a Minecraft server and I just updated Java to update 65, the server worked perfectly before updating but now, it says
"This Java instance does not support a 64-bit JVM. Please install the desired version."
Installing 32-bit Java doesn't help and this also happens when I run my Minecraft client.
I have 64-bit Windows 7 running 64-bit Java 7.
If anybody can help that would be great.
EDIT: Fixed it, apparently I'm just an idiot and had 32-bit installed when I updated java, and since I thought I had 64-bit installed I never thought to re-install it. Sorry for wasting your time
As the author stated, the solution was pretty simple. Bringing it to an answer to help future users
This java instance does not support a 64-bit JVM
This error is associated with your System looking for a Java 64-bit Virtual Machine and not finding any.
To solve it, you must make sure that the 64-bit Java is installed. The problem the OP had was: He assumed he had the 64-bit installed, but he did not.
To download Java, access Java Website
Because you are using 64 bit minecraft client, you are not able to work even with 32 bit JVM.
Kindly install all the things, mincraft server,client, JVM of 32 bit only. You can run it definitely. If still not able to work, let me know with exact error message you are getting.
Looking for some help with getting xdebug to behave with my setup. My goal is to be able to debug Joomla code.
First let me preface saying that about a year ago I was able to get a version xdebug to work with Eclipse PDT 2.1 with xampp under Vista 32bit. However, now I'm on a new machine, and I wanted to get everything working with the latest versions. I did so by following through this walk-through. Now, trying to do the same thing I can't get it to work.
First, as per the walk-through, I downloaded php_xdebug-2.0.0-5.2.2.dll. Quickly realized that I needed an xdebug for php 5.3. So, I found the xdebugs Tailored Installation Instructions and followed that. My php.ini section looks as thus:
[XDebug]
;; Only Zend OR (!) XDebug
zend_extension = "D:\xampp\php\ext\php_xdebug-2.1.0-5.3-vc6.dll"
xdebug.remote_enable=true
xdebug.remote_host=localhost
xdebug.remote_port=10000
xdebug.remote_handler=dbgp
xdebug.profiler_enable=1
xdebug.profiler_output_dir="D:\xampp\tmp"
So this got the xdebug to actually show up in the phpinfo(). But, in Eclipse when I Debug As Php Webpage, it at first appears to connect, however if I step to the next line of code the debugger just sits there saying it is stepping, indefinitely. Sometimes apache will crash. I tried ports 9000, and 10000 with no avail.
What I did find out is, if I use the the php_xdebug.dll that comes with XAMPP 1.7.3, I actually can connect and step without any issues, EXCEPT, that version of xdebug apparently has a major bug in it that causes all my variables to be listed as 'Uninitialized'. So it is basically useless, however, it does give some hope that I have some of this stuff set up correctly.
So, my current setup thus: Win7 32bit, XAMPP 1.7.3 (PHP 5.3.1, Apache 2.2.14), Eclipse PDT 2.2
I have very limited experience with basically all the tools here so I'm kinda at a loss of what to do. Any help would be greatly appreciated. I searched some of the other posts here with similar issue but most of them appear to be for older versions of these components.
your report is somewhat confusing. As far as I understand you, your setup works as soon as you replace the XDebug-dll. Then your (primary) problem cannot be related to your settings, as far as you also adjusted zend_extension, of course.
Though xdebug.remote_port=10000 seems odd. Std is 9000. If you use 9000, the you have to tell Eclipse in Window/Preferences/PHP/Debug/Debuggers to also listen to that port for XDebug.
Best
Raffael