What should a JSON service return on failure / error

Question

I\'m writing a JSON service in C# (.ashx file). On a successful request to the service I return some JSON data. If the request fails, either because an exception was thrown

Answer 1

I don't think you should be returning any http error codes, rather custom exceptions that are useful to the client end of the application so the interface knows what had actually occurred. I wouldn't try and mask real issues with 404 error codes or something to that nature.