Google AppEngine’s Smart Quota Doesn’t Match Reality

I love App Engine – I think it’s the best thing since sliced servers (bad joke)!  But one thing they got wrong is their “smart” quota management.  This has been something that has irked me ever since I heard a google rep talk about it at the Seattle App Engine Hack-a-Thon.

Here’s how it works according to the representative:  You have about 1 million free pageviews per month, but it’s not a simple you-have-exceeded-your-monthly-limit quota.  The app engine team has developed a way to evenly spread out your quota over the full month, so it is possible that you receive a generic “this account has exceeded its limit” page at the beginning middle or end of the cycle.  See anything wrong with that?

From what I’ve seen, most of the web properties that are looking for traffic do it in a very specific pattern that invovles two phases iterated many times.

Phase 1 – get a huge spike in traffic somehow.  Get on Digg’s homepage,  get a mention on Techcrunch, etc etc. You now have an unusually large number of visitors over a short period of time.

Phase 2 - a small percentage of those visitors will stick around and become loyal or engaged visitors.  This is the traffic you care about!

Here’s a snapshot of this site’s traffic after getting linked to by a popular internet pundit last month.  You can see the two phases very clearly.

One of the primary benefits of hosting in the cloud is that they are built to handle this type traffic profile – large random spikes!  Google’s App Engine is so promising as a platform because you can leverage their infrastructure to handle a lot of traffic.   But, very few sites have high, steady traffic – it’s mostly spikes like this.

But, with google’s “smart” quota – you have all the limitations of a single physical server!  When their quota system detects you’ve gone over your micro quota for the day, or the hour, or however they track it, then your site is officially taken down and a generic quota screen is shown.  Ouch!  Now that bump in steady traffic doesn’t quite stay as high as you’d like because many of those visitors that would stick around never get to see your content.

This very well may change when Google announces it’s pricing and other features, but for now this is a non-starter for sites that are looking to take advantage of google’s infrastructure to handle a lot of traffic.