Maximum number of concurrent NSURLConnections to the same host?

Question

I\'m running in to an issue in an OS X app that creates multiple, persistent connections to the same host using NSURLConnection. I create a separate connection for different

Answer 1

You could break this limitation by using CFNetwork API (CFHTTPMessage).

Here is the CFNetwork Programming Guide. https://developer.apple.com/library/mac/documentation/Networking/Conceptual/CFNetwork/Introduction/Introduction.html#//apple_ref/doc/uid/TP30001132

BTW, if you decide to use CFNetwork, you'll need to work around the proxy and authenticate.

Wish this could helped!

Answer 2

I filed a Radar for something that seems like the same issue but on iOS. I found that you can't have more than 5 connections open at once. The connections don't have to be pointing to the same domain. Anything after that would be queued. So if you have 5 connections open to an extremely slow endpoint, any other connections will not go through.

Radar: http://openradar.appspot.com/radar?id=2542401

Apple's reply:

This is the effect of our NSURLConnection connection cache. It is expected. We expect to address this type of configuration with new API.

I asked if they could give me anymore information (does it vary? does the type of connection affect it?) and they said:

Unfortunately, we can't give details about the connection limit behavior.

User agents in general (Chrome, Firefox, Safari) use six simultaneous TCP connections per hostname, with potential one-offs.