[pylucene-dev] Exceptions in PyLucene

[Andi Vajda]

On Apr 9, 2008, at 12:12, "João Rodrigues" <anaryin at gmail.com> wrote:

> I think your approach is flawed in several ways.
>
> maxheap is just specifying an upper memory limit, the VM is not  
> going to attempt to allocate or reserve that much memory until it's  
> actually
> needed.
>
> Instead, you could try to use the initialheap keyword with initVM()  
> but that doesn't work as expected either. If the VM cannot reserve  
> that much memory it doesn't exit gracefully. It sends a signal  
> instead, killing the process. If you experiment with this be sure to  
> _also_ set a maxheap value that is larger than the initialheap,  
> otherwise you're going to get a different error from the VM, also  
> signalled by a crash.
>
> >> I didn't mean maxheap, it was a typo :) initialheap was what I  
> meant.
>
>
> It seems to me that when any error occurs at VM start up time that  
> has to do with errors in the arguments passed to it, it doesn't fail  
> to start gracefully with an error that Python can report. It simply  
> kills the process with a signal. I tried to set signal handlers for  
> Python to handle the signal but it looks like the signal sent by the  
> VM is one of the signals that can't be hooked (SIGKILL). I don't  
> know how this behaves on Windows either.
>
> >> Gracefully is exactly not a word I'd use :) It currently gives an  
> error that doesn't shut down the script, and I have to "sudo kill"  
> it manually.. but that's probably because I'm messing with  
> lucene.JavaErrors, trys and excepts, in a ... messy way :)
>
>
>
> I also tried to see if there was a way to tell Java not to signal at  
> all. Following this in gdb, it seems that it's using a function  
> called JVM_RaiseSignal() to do its thing but I could not find any  
> documentation about it nor is it declared in the <jni.h> header file.
>
> >> Thanks for the effort :)
>
>
>
> A better approach to your problem might be to check via Python -  
> before starting the VM - what kind of memory your system has and  
> 'assume' that if enough is reported, the VM will be able to use it  
> if you give it to it via the initialheap and maxheap keywords.
>
> >> I'll try to do it this way. I was avoiding it 'cause I didn't  
> want to use any additional libraries and I'm not sure how to do it  
> yet, but I'll search.
>
>
> ----
>
> By the way, the problem I was having with the initialheap / maxheap,  
> it's "windows" specific.. I can run my script in the same machine,  
> in the Ubuntu 8.04 boot. I suppose it's a windows' specific  
> problem.. Is there a setting for "max memory usable by a VM?" in  
> windows?
>

Yes, it's maxheap and it's not Windows specific.

> Also, I tried to compile my scripts to an exe file, so that it's  
> easier to use (no python needed..). I found some troubles with the  
> jvm.dll but managed to copy it to the directory of the compilation  
> and it worked pretty well :) And quite small as well.
>
> And, to finish, I'd like to know how can I cite PyLucene in a  
> Bibliography of a scientific article. It's pretty much the  
> "software" core of my application so, you do deserve a credit :D

The credit goes to Lucene before going to PyLucene which just wraps it.
You're welcome to credit either whichever way you like.

Andi..

>
>
> Best Regards!
>
> João Rodrigues
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