I am currently looking into some performance issues we are experiencing, tested locally against a WCF service with a HTTPS endpoint, in the form of:
Note that the DNS alias services.mycompany.com is used.
When I test this I am on my local machine, and I have a SharePoint 2010 site that calls the service i a user control. And the first time a call is made to the service after a application recycle it takes about 80 seconds to receive an answer. Succeeding calls are fast. I’m am not able to reproduce the issue outside SharePoint with the same code, in a console application or a custom ASP.NET Web Forms deployed to IIS. Might see a little difference of about 0,5 second but nothing certain. No difference if I add a local DNS entry in the hosts file.
If I access via IP address instead:
Or via server name:
…it works fine! And the first call only takes like 4 seconds. What I saw also was that if my application used Fiddler as a proxy with the DNS alias, it also worked fine, although I don’t really know why that it.
So as far as I can tell, something in SharePoint is doing something with the DNS resolving? How can I investigate further and solve this issue?