# Threads, dRuby

**URL:** <https://www.ruby-forum.com/t/threads-druby/103217>\
**Category:** Ruby\
**Created:** [May 3, 2007, 1:50am UTC](https://www.ruby-forum.com/t/threads-druby/103217 "2007-05-03T01:50:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ddancer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ecb155/32.png) [@ddancer](https://www.ruby-forum.com/u/ddancer)\
**Post date:** [May 3, 2007, 1:50am UTC](https://www.ruby-forum.com/t/threads-druby/103217/1 "2007-05-03T01:50:35Z")

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Not sure where to start, so I’ll just jump in…

I have a dRuby server which runs a thread for each request.

The request fires off some processing that includes working with  
FireRuby and libxml, libxsl.

Here’s the weird thing about this. When I start the dRuby server, it  
always throws a FireRuby exception when the libxml opens an xml file for  
xsl transformation. But, it only does this the first time the server is  
called. All subsequent calls to the dRuby server run all code as  
designed without any trouble.

Now, I think it very odd that libxml appears to be throwing a fireruby  
exception. But even more so is that this only happens the first time.

I feel that something isn’t getting initialized properly; but obviously  
I don’t know what.

Any ideas on what might be happening?

I realize code helps, however it quite a bit of code. Thus I’m not sure  
what portion would be relevant.

any help is appreciated.

regards,

andy koch

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**Author:** ![ddancer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ecb155/32.png) [@ddancer](https://www.ruby-forum.com/u/ddancer)\
**Post date:** [May 3, 2007, 7:20am UTC](https://www.ruby-forum.com/t/threads-druby/103217/2 "2007-05-03T07:20:54Z")

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On 5/3/07, Andy K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Not sure where to start, so I’ll just jump in…  
> Here’s the weird thing about this. When I start the dRuby server, it  
> always throws a FireRuby exception when the libxml opens an xml file for  
> xsl transformation. But, it only does this the first time the server is  
> called. All subsequent calls to the dRuby server run all code as  
> designed without any trouble.

Have you tried running the code locally, i.e. not remotely via druby?  
Distributed Ruby tends to mask exceptions thrown by the called process  
in many cases in my experience, and the error you get tends to get  
obscured by the time it gets to the remote caller. All you know is  
that there was an error of some kind, just not what error it was. I  
have a couple of very large projects that use druby extensively, and  
this sort of behavior was so frustrating that I’ve made it a point to  
test any code intended to be run via drb by executing it locally  
first, and making sure that error handling is as bulletproof and  
robust as I can make it. It seems highly unlikely to me that libxml is  
really throwing your fireruby exception, more likely it’s throwing  
some other exception that winds up getting masked as one by the time  
it gets to the druby client.