Modperl memory exceedance under mason webmail

[Jim Donovan <ji...@aptnsw.org.au>]

Hi,

We run a webmail system which was written in Mason. It won't let you download or read large attachments (~5MB upwards). This seems to be some sort of memory allocation error.

If you watch the server with top(1) while downloading a 2MB attachment, you can see the memory usage climb quickly to 45MB. With larger attachments, growth is ppresumably even faster and some limit is passed, crashing httpd.

Does anyone know what is happening and how to control it, please?

Jim Donovan

Re: Modperl memory exceedance under mason webmail

[Adam Prime <ad...@utoronto.ca>]

Jim Donovan wrote:
> Hi,
>
> We run a webmail system which was written in Mason. It won't let you download or read large attachments (~5MB upwards). This seems to be some sort of memory allocation error.
>
> If you watch the server with top(1) while downloading a 2MB attachment, you can see the memory usage climb quickly to 45MB. With larger attachments, growth is ppresumably even faster and some limit is passed, crashing httpd.
>
> Does anyone know what is happening and how to control it, please?
>   
This is happening when you're serving a file that's encoded into an
email down to a logged in webmail user?  That just sounds like bad code
to me or something.  mod_perl doesn't do anything on it's own that would
justify that kind of memory usage just serving a file.  I could see how
it'd be easy to chew up RAM if you're reading a MIME encoded attachment
into a scalar, then converting it to binary, then serving it back to the
client though.

Adam