"Underlying connection was closed. Could not establish trust relationship" error

[Anna Troiken]

All,

We have an ASP.NET 1.1 application running on a W2K3 box that is consuming a
web-service via HTTPS and we are receiving this error, BUT, it's only
intermittent. It's not happening all the time. It just started happening a
few days ago and there was no code changes made to the server.

I've Googled this message and I see the various reason it can happen, but
none apply to us. The URL that we are using to hit the web service is the
same as appears in the SSL certificate that the web service provider has.
And the certificate is valid. And the problem doesn't happen all the time.
It works fine for a day, then starts up all of the sudden. When this
problem starts, the only solution is to run IISRESET, which will indeed fix
it, but only for a period of time. (Maybe a day, maybe a few hours.)

We've even made this change to our machine.config file:
<servicePointManager checkCertificateName="false"
checkCertificateRevocationList="false" />

but it doesn't keep the problem from unexpectedly starting again.

We're pulling our hair out over this since we can't make the problem appear
and are nervously waiting for it to happen again so we can quickly run
IISRESET. Help!

 

[Anna Troiken]

A few more things I've learned:

1. When this happens, the web application is unable to make any HTTPS
request to any other sites. We have another webservice that we consume and
once this problem starts, we are unable to talk to it either.
2. When this problem happens, we are able to consume the web services
through a console or Windows Form application. So the problem appears only
with IIS.
3. The effect is limited to either the web application or application pool
within IIS. I have another web application running on a different port and
within a different application pool and when the problem occurs, the other
application isn't affected.
4. The problem appears at random intervals and doesn't appear to be tied to
usage. It's appeared several times during low usage, some times it goes for
hours during heavy usage before it appears. Other times, it appears every
hour under heavy usage.

 

[Valko]

Hi,

unfortunately they may be many reasons for that, but basically connection
closed tells you that IIS timeout is reached - and the reasons may be many.
You can try to create separate pools for different web services and to
increase the timeout, but most of the time I have seen this error to happen
is because of the code you wrote - and the best solution to solve that issue
is your developers to start analyze what exactly they do in code

coding errors happens...