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Memory issues finally solved
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Loading ...As I posted before in ‘Mysterious problems with my VPS’, I recently got an increasingly unstable VPS system hosting a lot of my and my customers sites. After a lot of digging I initially presumed that Dovecot (the mail server) was responsible for the issues, as you can read in ‘Dovecot causing memory issues’.
Last week I did a lot of debugging on the Debian server to try and find out what was the issue. And initially it was Dovecots memory usage. After disabling this tool for a couple of days the server was still running fine. However the day after I posted the article on Dovecot the server crashed again. So I had to restart my investigation.
First off I had to had to get a better memory management tool, so I installed Htop on the server (apt-get htop). This shows the current memory usage of each running application. After installing this I enabled all services and applications again and started running stress tests. And though Dovecot was causing some peeks in memory usage it did not keep the high memory usage after the requests where done.
As it turns out for some reason Apache 2.2 was using a lot of memory during peak loads. But even more frustrating it didn’t seem to release any memory any more. Which was causing issues for services that only spawn when they are being accessed like Dovecot and Postfix, which explained why both of these services crashed when the server halted.
After tweaking the maximum amount of servers Apache is allowed to start and the maximum amount of client threads to handle the memory usage dropped dramatically. And I am very happy to report that the server has been running again for more then a week, without any glitches.
Still it doesn’t explain why all of this only happened after updating my server with the latest versions and patches. But I’m glad it’s solved for now.
Netbeans 6.5 Final Release
A short while back I wrote a quick review on the beta of Netbeans 6.5 and that it had some issues. Since the final version was released some time ago I thought it was time for a new review. This time of the final version.
The reason for me not to write one straight away was simple, I first wanna play around a little to find all the pleasant features and those less pleasant ones.
Bigger, better, best
The first thing you expect is this new version to be bigger, better and the best one yet. Well it is bigger in size, with 190MiB for just Java development. So this means a lot more time downloading, but hey that’s a one time thing.
So lets move onto something more relevant. Is it better then Netbeans 6.1. Lets summorize some of the issues I had with the previous version and see if the problem is solved:
- It crashed when working on larger projects. This issue has been fixed, netbeans won’t crash or hang. Though on occasion the parser may crash. Disabling autocomplete and syntax checking.
- For some reason previous versions had difficulty displaying the names of parameters when using Java libraries. For as far as I’ve been able to determine this has been solved.
- The autocomplete completely fails in some more complicated web projects. Well I’m sorry to say this is still true. For some projects not only does autocomplete fail, but so does the syntax checker, both for the JSP files as well as the Java Source files.
So are there any other changes that would make you consider moving from Netbeans 5.5 to 6.5?
New stuff you will like in Netbeans 6.5
Well have there been any changes that would make you wanna switch to the new version.
- The new version actually has some basic debugging integrated of JavaScript. Though I haven’t got it working yet.
- PHP development is now support. Which is a big plus, but it still kinda feels like a cheap addon that doesn’t work perfectly yet. (Maybe in the next release)
- Thread debugging has been improved and made easier
Unfortunattely not all is good in the world of Netbeans. There are also some new bugs, some of which are really annoying.
- For some unexplainable reason adding of libraries by right clicking the ‘Libraries’ in the project view doesn’t work all the time.
- Like I stated earlier the code completion fails in some of the older Java project I’m working on. Not only does code completion fail, but the syntax checker tells me every single line is wrong. Even though the project compiles beautifully
As a final note: is it worth upgrading to this version. Then I’d have to say hell yeah, it’s a lot better then previous versions. If you are a PHP developer however I suggest not using it, for the moment. Especially when you are already using Zend-Studio, which is still a lot better.
Weird and complicated memory issues in C++
Sometimes when you are developing you encounter the stranged errors. Today is just such a day. I’m right now having issues with memory access violations in on of the programs I’m developing.
This on its own is not that big of a deal, but I can’t seem to trace down why it’s happening. If I debug the function that causes the error has no issues. No memory violations, but when I continue running (without debugging every single call) then all of a sudden at some point in time I get a memory access violation.
Now I don’t exactly know where it’s comming from. It may have something to do with the fact that the object I’m deleting is a prototype of a prototype. And also occasionally gives me an error during compile time that I have no destructor in the class. But when I compile the files one by one it does not give this error. And the class in question does have a default destructor.
Hmm, guess it’s time for some real line by line debugging and digging into the internet about the obscure error message I got.
