I'm making a POST request to a nodejs server that contains just a file name in the body. Upon receiving the request, node uploads the corresponding local file to an Amazon S3 bucket. The files can sometimes take awhile to upload, and sometimes the request times out. How can I lengthen or prevent the timeout from happening?
You can send the response back to the browser while you still continue to work on the upload. You don't have to wait until the upload is done before finishing the response. For example, you can do:
res.end("done"); // or put whatever HTML you want in the response
And, that will end the post response and the browser will be happy. Meanwhile, your server continues to finish the upload.
The upside to this is that the browser and user goes on their merry way to the next thing they want to do without waiting for the server to finish its business. The only downside I'm aware of is that if the upload fails, you don't have a simple means of informing the browser that it failed (because the response is already done).
The timeout itself is controlled by the browser. It is not something that you can directly control from the server. If you are continually sending data to the browser, then it will likely not timeout. So, as long as the upload was continuing, you could do something like this:
res.write(" ");
every 15 seconds or so as sort of a keep-alive that keeps the browser happy and keeps it from timing out. You'd probably set an interval timer for 15 seconds to do the small send of data and then when the upload finishes you would stop the timer.
If you control the Javascript in the browser that makes the post, then you can set the timeout value on an Ajax call from the Javascript in the browser. When you create an XMLHttpRequest object in the browser, it has a property called timeout which you can set for asynchronous ajax calls. See MDN for more info.