title: Refreshing RSS feeds at near-realtime intervals
body: <p>I've got a system that fetches a few hundred RSS feeds. Currently they're on a 10 minute refresh cycle, but I'd preferably like to make that faster. What is a strategy to fetch the RSS sources at near-realtime/push intervals?</p>
  
  <p>Some solutions I've come across:</p>
  
  <ul>
  <li>do a fetch at 1 minute; if no changes, fetch again at 2, then 4, then 8, etc.</li>
  <li>find the average time-between-updates interval/variance of the RSS feed, and put them in a bucket (this one updates every 3 mins, so do a check every 1 minute; this one updates every week, so do a check every day, etc.)</li>
  </ul>