The cpu in the equation is a 1ghz equivalent cpu which is not necessarily the same as the cpu you request ran on.
- alkis (mobile) On Aug 17, 2010 7:41 PM, "MyElasticEye" <[email protected]> wrote: > Hi, > > I have been trying to optimize the App Engine application my team is > working on. As I read on Google's documentation, > > 1 megacycles = 1/1200 cpu seconds > > And if I a check how many megacycles it takes to load an empty sinlge > page without any templates using webapp.py, it takes 0 megacycles. > However, the amount of cpu miliseconds used for the request usually > becomes around 200 ms. That's understandable because of the overheads > of the request. > > However, I see that when I do like: > > class SomePage(..): > def get(self): > start = quota.get_request_cpu_usage() > # do some dense operations here... > end = quota.get_request_cpu_usage() > logging.info("the operation cost %d megacycles." % (start - > end)) > return > > I can't see a relation btw the megacycles it takes and the cpu > miliseconds used. According to the equation above, 1200 megacycles = 1 > cpu second, and if the result of the operation is 2400 megacycles, it > means that it should equal to 2 cpu seconds. Let's say there is an > overhead occuring even if we load an empty page or whatever, and then > it should equal to 2400 + 200 = 2600 ms > > However, the logs of the request says that it takes much more than 2 > cpu secs, more like 7000 or 9000 cpu milisecs. > > Why is this occuring? > > Thanks > > -- > You received this message because you are subscribed to the Google Groups "Google App Engine" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to [email protected]<google-appengine%[email protected]> . > 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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
