failed to allocate memory

Hi all,
        Am running apache as frontend to mongrel ,i am passing request
to mongrel using passproxy like
ProxyPass / http://localhost:3000/

i have download routine in one of controller and now i would like
Apache to server this request...for that i put a line in httpd.conf

ProxyPass /streams/download/6626/ !

now my request for download should be handle by Apche but when i go
task manager and see the memory usage..
ruby.exe is consuming 1,240,460k
abd httpd.exe is still 24,656k

how do make Apache to server and after 1.1 gb of file being downloded
ruby.exe is still consuming 1,240,460k and when i try to download 1.1 gb
of stream again ,i am getting failed to allocate memory