To prevent browser timeout during a long running process, I've got the following code to work nicely,when the browser accesses Zope directly (e.g. http://myzope.net:8080/folder/client001/) context.REQUEST.response.write("progressing...") #do some stuff context.REQUEST.response.write("further...") #do some more stuff context.REQUEST.response.write("done!") However, when browser goes through the Apache reverse proxy, e.g. <VirtualHost *:80> ServerAlias site1.foobar.com .... RewriteRule ^/(.*) \ http://localhost:8080/VirtualHostBase/http/%{SERVER_NAME}:80/%1/site001/VirtualHostRoot/$1 [L,P] I get all three writes (progressing..further...done!) at once, at the end of the processing. I'm running Apache 2.0, Zope. 2.7.6, Plone 2.0.5 on Linux From going through Apache docs and discussions (notably http://www.gossamer-threads.com/lists/apache/dev/305433), it appears that this is an Apache 2.0 problem. Is there any way to get the same behavior (unbuffered writes) even when I go through the Apache reverse proxy?