Hi Gerald, Have you looked at what the XMPP presence looks like for the pairs? Many systems (including Google Chat) will send back 2 responses a basic one and then a more detailed one. I don't believe this is a bug in our system but rather standard practice, but if you are getting 2 identical requests back and the other system is not sending those (in other words, you only get 2 when using our XMPP presence), let us know.
The scheduler is not trying to spin up useless instances but if you don't have any instances running, then get 2 requests in, the scheduler will take you loading time into account and likely see that it won't be able to service both requests in the amount of time needed hence spinning up 2 instances. Do you see a difference in the number instances created if there is already an idle instance running? It might spin up fewer instances because it doesn't need to wait for the instance to be ready to serve the first request and therefore can have the second request wait. Does that make sense? Greg On Sun, Sep 4, 2011 at 1:50 AM, Gerald Tan <[email protected]> wrote: > I've been trying to keep my Frontend Instances under control for a very-low > traffic application that should remain under all other quotas. I have > enabled multi-thread, set Minimum Pending Latency to 15s, and Max Idle > Instances to 1, and hope to use only 1 Frontend Instance to stay under the > daily quota for Frontend Instance Hours (because anytime a 2nd instance > spawns, it is almost guaranteed that I will exceed the daily quota), but it > seems impossible with the Scheduler deciding to spawn extra Frontend > Instances for no reason other than to bill us higher. > > What I've noticed happening is XMPP Presence Available requests always > coming in pairs. Not sure if this is the correct behavior from XMPP clients > or if this is a bug in the GAE XMPP engine double-sending XMPP Presence > requests. This is fine if there is an Instance ready to handle them, but > when I don't have an Instance up, the scheduler will spawn TWO (or even more > if some other requests come in at the same time) instances to handle both > requests simultaneously. > > I'm guessing my daily Frontend Instance quotas will run out maybe 2-3 hours > before the end of each quota-day because of all the unneeded 2nd Instances, > and I'll have to pay $9/month to make it available 24 hours per day. > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/google-appengine/-/ETL0ufhzwfYJ. > 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. > -- 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.
