On Tue, Dec 1, 2009 at 6:49 PM, Stephen <sdea...@gmail.com> wrote: >> I should say that a query with 1 result takes about 30ms. 128*30 = >> 3840 ms. That's pretty close to what I'm seeing for 128, indicating a >> linear scaling in the number of entities. Which would be really bad, >> and unexpected. >> >> It's really hard to guess what's going on internally, without any >> visibility of the architecture. > > > This is a recent change. It used to be that you were charged whatever > api_cpu it took to run your query, as measured on the machines. Now > there seems to be an algorithm that generates the cost based on your > entities and query type, so it will be the same from query to query. > > This is good because now your costs do not suddenly go up 30% because > Google's infrastructure is having a bad day. The incentives used to be > all wrong. The change is bad because Google didn't announce it. Are > the api_cpu costs exactly the same as before? If not, it is an > unannounced price in/decrease. > > >> Has anybody looked (publicly) at datastore performance depending on >> query size, locality, etc? If not, I might try to gather some >> extensive data, and write it up. > > > It would be nice to work out what the algorithm for api_cpu is...
Note: I am *not* using api_cpu time (not available in the Java runtime, as far I know). I am using system wall-clock time. I am doing the Java equivalent of two gettimeofday() and computes the difference. So the way api_cpu and co are computed is an entirely different question. -- 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-appeng...@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.
