Delayed responses for cURL SSL PUTs/POSTs (php) (NSS vs OpenSSL)

Question

I have two Fedora-based apache webservers making the same SSL PUT/POST calls with php/cURL. One works fine, but with the other the call succeeds but takes a VERY long time to return a response (~10 min). (GETs don't seem affected)

The working server's cURL uses OpenSSL for SSL, while the non-working version uses a later version of cURL that uses NSS for SSL

I know nothing about SSL implementations or their effect on cURL. What would cause such a significant delay in SSL PUT/POST responses?

Any suggestions appreciated- Thanks--

Answer 1

I can only guess, but some SSL implementations end up trying to do unnecessary reverse DNS lookups and these can take a long time to time out.

Answer 2

Yes, i would bet on a DNS issue along the lines.

Try run a trace route from root and get some connection figures.

Do it on both machines so you can see where there issues is first showing up in the Debug.

Answer 3

I don't know the answer. DNS recommendations are always good. Other ideas include MTU discovery, server not providing intermediate certs so the clients may be trying to download missing intermediaries or an attempt to check the CAs recovation list.

Download wireshark and you should be able to get a better idea of the difference in behavior between clients.