Google App Engine request cost estimation

0
votes

I'm trying to estimate the cost of requests in a prototype app deployed in Google App Engine (free, not billing enabled) and I'm having some questions and issues. Right now, just to see if I could get things working I've just deployed some JSPs that generate some HTML.

Issues:

  1. I'm logged as an admin but not getting the "X-AppEngine-Estimated-CPM-US-Dollars" header on JSP responses. Does this only work for explicitly registered servlets?
  2. I'm getting the "cpm_usd" value on admin console logs view, but not on dowloaded logs. Is this value valid? Anyone got it compared with the one on the headers?
  3. How does static files cost work? I get mostly the same "cpm_usd" value independently of file size or response code (200 or 304). I have not defined a caching policy yet.
  4. The "Quota Details" page says I have consumed 1% of my free "Incoming Bandwidth" but 0% of "Outgoing Bandwidth". That's just impossible. Only explanation I found is that there's a bug and the values are interchanged.
  5. It seems that full uptime instance time (with those extra 15 min) is only considered for billing, as my consumed free quota for that is 0% (so it must be processing time). Is that correct?

More general pricing questions:

  1. About Reserved/Prepaid Frontend Instances: how do you "purchase" them? How do they go along with the free 28 hours? Are resident frontend instances (minimum idle instances) paid as reserved? Shouldn't they be?
  2. About Backends: the free part is 9 hours or $0.72? (it's not the same depending on the backend class)

Finally, if someone has any good advice, strategy or formula for estimating costs on GAE, they are very welcome to share them.

2
javagoogle-app-enginebilling
Sure estimating costs is not easy, it's not easy with GAE, is not easy with EC2. I believe there is a minimum of 9 dollars per month in billing, and with that you should go a long way, especially if you use memcache extensively. You can also set up a maximum daily budget, so you don't get bad surprises. Just try it, if you're unsure try to not tie yourself too much. In general the costs are a little lower than EC2, even if not all is comparable, since EC2 is IAAS and GAE is PAAS. - stivlo

2 Answers

2
votes

I've found the article App engine new pricing model, that might be helpful.

1
votes

Remember that most costs are an estimation of real costs. As stivlo point out, estimating an aggregated cost is not easy (consider the sum of millions of 0.00000001$ , to get an idea).

A good tool to estimate your cost for Appengine is this awesome Chrome Extension: "App Engine Offline Statistics Estimator", but again it's just an estimation.

If that's not enough, you might want to check out the AppStats package for Python or Java.