So I'm getting some weird behavior when using an NSURLSession. Our app uses two separate sessions. And we aren't doing anything special when making them. This is it:
let configuration = URLSessionConfiguration.default
configuration.waitsForConnectivity = false
configuration.timeoutIntervalForResource = 30
self.init(configuration: configuration)
All we do is create data tasks using
session.dataTask(with: request)
After creating about 100+ data tasks and having them complete successfully with no problems, the session will hang for the full 30 seconds and return a -1001 "The request timed out." error. The next few tasks on this session will fail, and then all of a sudden the NSURLSession will start working again.
Now the weird part is... since I have two NSURLSessions, only the one that has hit 100+ tasks times out. The other NSURLSession can still contact the same server URL and run tasks just fine.
I did put this through the Network Instrument and one thing I did see is that up until the timeout happens the NSURLSession will use a single connection as expected. But after the 30s timeout and the recovery it looks like the NSURLSession decides behind the scenes to make a brand new connection and that's where the "recovery" comes from.
Out server team swears this isn't them as other non-iOS clients hitting the same endpoint don't have this error. Any help?
(Side note: I can fix this in my app by just making a new NSURLSession every 100 tasks, but that doesn't really help me understand what could be going wrong in the first place).
