Truncated response via mod_proxy

I’m trying to debug an issue with a client getting a truncated response via mod_proxy and mod_ssl on apache 2.0.63. The client software is SQLAnywhere, and they are trying to get a response from a backend web service running under IIS6. If they make the request directly against the origin server via SSL or port 80, it works. If they query via the reverse-proxy on port 80, it works. On SSL via the reverse-proxy the results are truncated (only part of the XML is returned).

This reverse-proxy serves hundreds of vhosts and thousands of clients a day. This is the only vhost + client with a problem.

Using wireshark, we can see that the rproxy is sending an encrypted alert 21 and then client is sending an SSL alert 21 and closing the connection.

I’ve set Apache’s LogLevel to debug, and I can see the incoming SSL handshake and the request, and I can see the mod_proxy working, but I don’t see a detailed trace of the response going back (even though a partial response is sent). The access log says that the whole response is returned. Is there some special command to trace the response?

Regards,

Ryan