Hi Jeff, Check this post : https://groups.google.com/forum/#!msg/google-appengine/3t5muVhXajg/SSFU-udjIhwJ
Setting "Idle instances" to automatic, as Johan Euphrosine suggested, seems to have solved the problem, at least temporarily (I was at 1 minimum and 1 maximum before). I'm just a bit scared now to get over my daily quotas. François On Tuesday, February 28, 2012 5:34:36 PM UTC+1, Jeff Schnitzer wrote: > > There's been a lot of discussion of the scheduler behavior in Pythonland, > but not much about it's "eccentricities" in Javaland. > > I have a threadsafe=true Java app. Let's say every request completes in > exactly 1s. Settings are: idle instances min 1 max 1, latency auto/auto. > Here is what I expect: > > * Instance1 starts up and becomes permanently resident > * Instance1 serves concurrent requests up to some arbitrary CPU capcity > * When Instance1 exceeds capacity: > * Instance2 starts warming up > * All requests remain in the pending queue for Instance1, getting > processed at 1/s * concurrency > * Instance2 is ready and starts processing new requests, sharing the > load with Instance1 > > What I actually see (as far as I can determine): > > * Instance1 starts up and becomes permanently resident > * Instance1 supports almost no concurrency. At most it's 2. (no, my app > is not particularly compute intensive) > * A new request comes in which for some reason can't be handled by > Instance1: > * Instance2 starts warming up > * The new request is blocked on Instance2's pending queue, waiting > 10-20s for Instance2 to be ready > * In the mean time, Instance1 is actually idle > * Another new request comes in and starts up Instance3 > * Possibly this is while Instance2 is warming up > * AFAICT, Instance1 is taking a coffee break > > The net result is that I have an idle website with 1 user (me) clicking > around and I've already gotten multiple 20s pauses and three instances. > Something is seriously wrong here. Whether or not it's rational to have > so many instances started, pending requests shouldn't be shunted to > non-warmed-up servers, right? > > I've tried upping the min latency to a high value to see if this improves > the situation. If this works... shouldn't min latency *always* be as high > as the startup time for an instance? > > I know it's been said before, but it needs to be said again... the > guidance for scheduler configuration is really, really inadequate. > > Jeff > -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine-java/-/zULJyO6VtHwJ. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
