Question

Been banging our heads on this for two weeks now. Any help will be greatly appreciated.

Problem:

I am using NSURLConnection to fetch JSON data from a RESTfull Web service, the requirement is such that I can’t do lazy loading of data. It is one big chunk of data that needs to be processed on the 1st screen of the app every time the logged in user opens the app. I know its not a smart thing to do, but can’t help it. The caching is being done in the local Sqlite DB. We are using Async NSURLConnection that is giving us a constant 3-4 sec hit on the performance.

We tried Sync NSURLConnection and figured out the Async NSURLConnection is taking around 3-4 sec extra to process the same request. But Sync NSURLConnection is not reliable at all, it fails to get the complete JSON more than half of the times. And the combination of Sync NSURLConnection with NSOperation will not help.

We tried making the call in a separate app just to observe the performance for that one particular request, and still got the same results.

So, currently we are getting an average execution time of the complete request to be around 6-8 sec. Which we feel I quite high for your first screen of the app. (please let me know if its not much, it feels like bad user experience to me).

Questions:

Isn’t NSURLConnection the standard way for doing a request like this?

Is there a better and faster (reliable) way of doing this apart from NSURLConnection?

Can I optimize the performance of NSURLConnection? If yes, please point me to the right direction.

Has anyone tried CFHTTPStream? If yes, then is it better than NSURLConenction in terms of performance?

Thanks

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@GoZoner Thanks a ton for the response. We tested in the below three ways

1. Since it is the 1st screen of the app, so there is no real case of the app doing anything else, still the results were different and a consistent 3-4 sec loss with Async.

2. We made a raw call in a separate test app, which did nothing but just that one web service call and still the results were same.

3. We tested on the device and on the simulator. On the device, as expected the results were worse, around 4 secs constant lag in an Async NSURLConnection call.

We were also surprised with the reliability issue as it makes very little sense that a Sync NSURLConnection is unreliable. But after running the tests a zillionth time we realized that it is actually not reliable, not because of something in the NSURLConnection library, but because the 3G or Wi-fi connections are not reliable so the call use to break mostly due to the connection(my assumption). This particular problem is handled beautifully by Async NSURLConnection since it keeps calling and appending data till the data received is complete.(This can sometimes take more than 10-12 attempts to append the data to complete the JSON). Since the Sync NSURLConenction is making only one attempt in getting the data, it fails miserably in the unreliable mobile network connectivity.

@Andrea Thanks for the response 🙂 Will surely give YAJL a spin. But i believe that the problem is more with the connection rather than the parsing of the JSON, I may be wrong. Does YAJL have a reliable connection handling mechanism?

Looking forward to more responses, your suggestions and comments are actually very valuable 🙂

Thanks

Answer 1

try to use ASIHttpRequest the response time may be faster than the NSURLConnection.