over come HTTP client time out issue

Question

I have an api end point which receives some parameters and process them returns a csv file. But the processing time may take more than 15 seconds. My server has build in timeout and some client systems may have also timeout set.

How can I overcome this timeout issue with out changing any system settings?

I have gone through some articles, which says make a api call for registering the job, send back 202 response from server with a retry_after header, then process the data. Client resend api request after specified time, if process not complete repeat the cycle till process finish.

I don't know how to implement this in php. Any help will be appreciated...

Answer 1

The general principle here is fairly simple, and independent of programming language (PHP vs Java vs ...) and transport mechanism (HTTP vs message queues vs ...). When a request comes in to the API, determine the state of the request from your persistent store:

1. Complete. Return the results and you're done.
2. In progress. Return a "please wait" response to the client.
3. Not started. Create a new record in your persistent store for the request, start processing the result in a background task of some kind and return "please wait" to the client.

A lot of the complexity in this sort of thing comes from the more precise requirements - for example, what counts as the same request? If two clients make a request with the same parameters, is that "the same request"? Similarly, you need to think about when to invalidate the cache of results - how important is it that clients get the absolutely very latest results as opposed to getting them quickly? These are all things for which there is no right answer - it depends on your specific use case.