(1) is correct. (2) is wrong because it is assuming things are the same all day long which is not true in your example, in your example, there are three kinds of minutes, the [0:5] range, the [5:20] range, and the [20:60] range. The three ranges need to be computed independently (as the billing formula would) which yields 14 instances hours (and thus free).
On Thu, Sep 8, 2011 at 11:11 PM, Tammo Freese <i...@flockofbirds.net> wrote: > Hello Jon, > > > sorry to hassle you again. Her is an example: > > An app gets a 5 minute traffic spike at the start of each hour, > leading to four instances being active the entire five minutes. Then, > the app gets > no more traffic for the rest of the hour. max-idle-instances is set to > 1. That's basically the scenario described in > (1) http://groups.google.com/group/google-appengine/msg/db996f64d427d66c > but with traffic each hour instead of once a day. > > From (1), I would estimate the billed minutes to be 35 * 24 = 840 (14 > hours), so the app would be within free quota. > > Looking at (2), I come up with 32 hours: > > (a) 4 instances are active 5 minutes every hour. > (b) That is 5*60*4*24 = 28,800 active seconds for the day. > (c) active-instances-rate is = 28,800/60*60*24 = 0.3333 > (d) total-instances-rate = 20*60*4*24/60*60*24 = 1.3333 (total > instances should be 4 for the 5 minutes spikes + 15 minutes after the > spikes) > (e) billable-instances-rate = min(active-instances-rate + > max-idle-instances, total-instances-rate) = min(0.3333 + 1, 1.3333) = > 1.3333 (32 hours) > > Which of the solutions is right, and what have I done wrong at the > other? > > > Take care > > Tammo > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to google-appengine@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
