Hello JDownloader community, first of all I love your product, that said I have just registered on the forum to share with you something that made my day.

- If like me you are using Windows 7 (affects Vista, Server 2008 as well),

- If like me you are using an advanced antivirus with a web (HTTP checking) access scanner/protection (affects all latest versions of ESET NOD32 & SmartSecurity, AVG, Symantec/Norton etc... with the exception of Microsoft Live Security which does not have such advanced feature)

- If like me you are using the latest version of JAVA (24, affects all versions)

- If like me you are using the latest version of JDownloader

Then you are certainly facing a driving to crazy humongous memory leak that will take up over all your RAM (even 12G+) which will make your system unstable after a few fair hours of intense http download.

Perhaps like me that makes you mad and frustrates you, perhaps like me you searched the web for an answer, is it JAVA which is crap? (easy one), is it jdownloader's fault because it's JAVA and it's crap? (once again), is it my antivirus solution that is so so bad even if I love it? Then again is it Windows.

Well my friends today I found the solution and if like me you stuck for hours to find it (of course if you found it like me, hooray, sharing is caring!), then I can help you!

First of all I believe many people went for the easiest known way being to de-activate your antivirus HTTP scanner which makes some of them showing an alert that your protection is incomplete and that was something you agreed to live with.

Here is the damn real problem explained:

Nowadays almost all modern and advanced protection suites including antivirus, firewall and so on are proposing by default this famous HTTP scanner that calls for Windows Filtering Platform (WFP) callout driver which will be used as a base input for scanning your browsers, downloaders and any HTTP activity whatsoever. Well my friends this WFP is the root cause of the memory leak and no Service Pack, no KB or update can solve this problem, only a specific hotfix fr your platform can save you!

How to check that you are affected by this problem

After some hours of download and if you realize your RAM usage is growing enormously then open a task manager and go check in the lower corner of the "Performance" tab for the section "Kernel Memory (MB then check the values of the Nonpaged memory, a normal result should never exceed say 100MB, if you are affected by the WFP memory leak then my friends you will see scary values like 4/5000MB for a 6GB RAM system... and I believe you wondered so much where the hell your memory went because in the "Processes" tab you were not able to see which process is taking the RAM, that my friends is called a memory leak and in this case it's absolutely not Oracle/SUN's JAVA fault nor the JDownloader coders nor the antiviruses coders but Microsoft, and the principle is simple, paged memory is say the memory your applications are actively using and can't be freed for anything else, now on the other hand the non-paged memory is the memory that your applications are using temporarily and that will be freed interactively according to your applications needs, well too bad a memory leak is out of your applications control and affects your OS kernel directly resulting in a simple fact: you just can't free it and it will continue leaking until it freezes your system, that's it.

How to fix this problem!

Simple my friends, if you want Microsoft gibberish explainanation you may find it here

Otherwise if you are so damn lazy like I am, here is the direct link to the hotfix web page to request the hotfix according to your platform, a valid email address is needed! Microsoft will send you instantly a mail in which you'll find a link AND a password for the archive to unpack, then launch the hotfix install follow the instructinos, reboot and voilà! No more memory leaks whatsoever, an antivirus of your choise that runs the way it should with all the functions and finally the pleasure of enjoying JDownloader the way it is meant to be!

Just my 2 cents, if I may help just one person then my time was worth and I'm glad! Feel free to leave a comment if you have questions or just want to thank the artist

Thanks for sharing that information.

I wonder why M$ doesn't include that fix in its automatic updates.

Originally Posted by remi

Thanks for sharing that information.

I wonder why M$ doesn't include that fix in its automatic updates.

You're very welcome and I believe they don't include it in a KB or SP because it does not apply to every Microsoft Windows Vista/7 users but rather a specific situation that requires the users to apply it.

A brilliant idea would be to find a way to integrate the content of the patch in the JDownloader install, what do you think?

An easy way would be to unzip the kit with the password and split-stream them in JDownloader's install pack (the web install pull) e.g. with a check box "I am using an antivirus", of course that will require the reboot.

But I believe many people are impacted by this with the result that people may think it's JDownloader's fault or JAVA (the usual), which is not

I don't think it's a solution, because that would mean that many programs would try to install the same patch. At least those that use that WFP.

I don't understand why a patch, that might avoid problems, is not installed by default. Does it have any negative side effects such as with most (non-)prescribed drugs?

[editestowy]

@remi
I think MS probably doesn't know exactly what the problem is, so they would rather not risk millions of furious users when this patch crash their systems
@dondrei
This patch shouldn't be distributed with jD, because if the system crash after instaling it ("Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing.") - users will blame jD for it.

However the info is valuable and probably should be inserted somewhere in the Knowledge Base.

@remi & editestowy
You are completely right dears, I did not think of the side effects. This better should be left as an external workaround for the users to apply if needed as you said.

Anyhow and just for info purpose, after 3 days of 24/24 http download @ 30mbits I can confirm that the memory leak is completely gone, my non-paged RAM usage is still 60MB which is good, additionally the javaw.exe*32 process in which JDownloader is encapsulated grew from an initial ca. 200MB to 500MB (so in 3 days) so it looks to me that in this case it's JAVA's stack heap overflow that's responsible of not freeing it after usage (Java apps don't swap gracefully at all. I think because of Garbage Collection, java constantly pulls its memory from swap.) or JDownloader's routine. I am playing with the -Xmx***M options to figure how to prohibit JDownloader's process to take more than 300MB which is a fair limit for an application like this... I keep you informed of my results and any other info about this would be appreciated.

Cheers to all!

Well its good you figured it out. I recommend people to use comodo to avoid such problems, its a great software and doesn't have that web scanner. If anyone is interested in comodo heres the link and its free > **External links are only visible to Support Staff****External links are only visible to Support Staff**

The only problem with comodo was the cmdagent.exe consuming %90 percent of the cpu and I think that problem is gone after its latest updates.

Thanks for this, will give a try.

Thanks a lot for the trick!

thanks dondrei! that fix worked! I was about to throw JD out the window and switch to another DM, gave this memory leak problem a final try, and very luckily found your solution! now I can finally use JD without having to constantly reboot which always meant annoying interruptions to whatever else I was doing. this fix really made my day!