mod_ssl + "large" form variables, variables go missing

Form variables all disappear when one is more than a few K in size

[aus129]

I am running a virtual host in Apache 2.0.55 using mod_ssl + OpenSSL 0.9.8a on Win 2k3 Server. It seems to truncate POST requests that exceed a few kilobytes.

Here is the scenario: Apache uses a rewrite / proxy rule to forward requests to Zope:
RewriteRule /(.*) [localhost:8080...] [P,L]
When this rule is applied to the Virtual Host on the secure port 443, there is a limit to the size of the request variables that it will forward to Zope. When the rewriterule is applied to Apache globally and requests are done over port 80, any size variables will be passed to Zope. The large requests usually come from XML files, so I tried unsetting the LimitXMLRequestBody directive.

Here is my virtual host configuration:

<VirtualHost *:443> 
ServerName denproduction.fqdn:443 
ServerAdmin wdyk@fqdn 
TransferLog logs/access_log 
LimitXMLRequestBody 0 
SSLEngine on 
ServerName denproduction.fqdn 
DocumentRoot C:/Apache2/htdocs 
ErrorLog logs/ssl_error_log 
SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL 
SSLCertificateFile ssl/denproduction.cert 
SSLCertificateKeyFile ssl/denproduction.key 
SSLOptions +StdEnvVars +CompatEnvVars 
SetEnvIf User-Agent ".*MSIE.*" \ 
nokeepalive ssl-unclean-shutdown \ 
downgrade-1.0 force-response-1.0 
CustomLog logs/ssl_request_log \ 
"%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b" 
# Rewrite Rules for Zope 
<IfModule mod_rewrite.c> 
RewriteEngine On 
RewriteLog C:/Apache2/logs/rewrite.log 
RewriteLogLevel 0 
# Default to route everything to Zope 
# If the path starts with /local, then just server Apache's root 
RewriteRule ^/test/ - [L] 
RewriteRule /(.*) [localhost:8080...]  [P,L] 
</IfModule> 
</VirtualHost> 

The problem has occurred when I make POST requests from the Python client that I am writing, as well as when I am managing large python scripts through the Zope management interface over SSL.

Any pointers are appreciated!

[fumarks]

I have the identical problem running on FreeBSD 5.4 and 6.0, running httpd in reverse proxy setup talking to backend tomcat servers.

Screens that depend on large numbers of post variables fail.

Interestingly the problem goes away if I run http-2.2.0

However, I too would like to understand this problem in case they fold whatever bug is in 2.0.55 forward to 2.2.0

--mark