Hypothetical: if you deploy a webpage for a time-limited event (e.g. vote results) with an async update cycle, what options for throttling do you have if your l

Hypothetical: if you deploy a webpage for a time-limited event (e.g. vote results) with an async update cycle, what options for throttling do you have if your load exceeds expectations? Is there a best practices for having a server-controlled "Plan B" throttling mechanism? I'm making the assumption that the majority of users will load the page and leave it running unmodified.