Potential problems in setting AsyncPostBackTimeout to large value (300s)?

Question

Are there any reasons to not set the ScriptManager.AsyncPostBackTimeout to a (comparitively) large value like 5 minutes?

I have a report that takes anywhere from 30 to 180 seconds to run, which causes a Sys.WebForms.PageRequestManagerTimeoutException: The server request timed out. error.

In all my searching I can't find a downside of a large timeout, but I'm wondering if anyone has hands-on experience and can attest to whether it's safe to increase it well above the default 90 seconds?

Answer 1

I've been running this for over 8 months on an application that gets a moderate number of asynchronous postbacks per hour (<1000), and I haven't run into any problems with AsyncPostBackTimeout set to 300 seconds. I can imagine it creating problems if there are possibilities of extremely long running requests happening all the time, but it seems completely stable currently.