I have a site that uses the php SOAP client to connect to a ticketing system API, occasionally a call will throw up an exception saying 'Could not connect to host'. I'm pretty sure the SOAP server isn't going down so I'm struggling to understand what might be causing this. I can't reproduce it myself either but I can tell it's happening from the logs.
The site is running on php 5.3.3 and connecting to the server over https which might be a factor.
Does anyone have any ideas what might be causing this?
This did get solved, turned out that the firewall of the ticketing system we were connecting to had a setting that limited the maximum number of connections from a single I.P. address. Since all the API requests were coming from one IP (the webserver) we were hitting this limit which triggered the error.
To fix it an exception was added for our IP and we haven't seen it since.
I was getting this error due to the fact that php didn't have the OpenSSL module installed and the service I was authenticating against required it. If it's only happening intermittently though it sounds like there's a break in the connection along the way, either on your end or more likely on the end of the service.