While waiting from a Googler to give us some light on this may be you do your stress tests in the staging server ? (just an other version will do as staging server) Also I remember people from App Engine team stating here that the best performance comes when load comes in a natural matter.
Still IMHO that there must be some more transparency into those parameters within which our appls have to operate. - It helps both us and the platform. Regards Nick On Nov 24, 9:21 am, Tomas Alaeus <[email protected]> wrote: > Probably. With some more thinking I got to this conclusion: > > At first, an application can utilize up to 30 instances. After having > used all those instances for a few minutes, and it still isn't enough, > GAE will increase the maximum number of available instances to 40, and > then to 50 etc. Every time it increases the number of instances it > will probably also adjust how and when it boots up new instances. > > For my production app it probably tries to keep at least 10 instances > running since it thinks a huge amount of users can use the site at any > given time. The staging haven't had any rush of users, and therefore > thinks it is safe with just 1 instance running. > > I would still like to hear something from a Googler. If this is how it > works then it means that stress testing the application (with a lot > more pressure than it will normally get) may lead to worse (!) > performance permanently. > > On 24 Nov, 00:01, nickmilon <[email protected]> wrote: > > > > > > > > > Not been a Googler can't help much with this. > > Having said that, I suspect there is a kind of build in algorithm that > > does some kind of application profiling taking into acount QPS, > > response times, and other parameters which adjusts instance life time, > > number of instances to start etc.. > > This could possibly explain the difference in behaviour between your > > staging and production appls. > > > happy coding;-) > > > On Nov 23, 11:58 am, Tomas Alaeus <[email protected]> wrote: > > > > I'm curious when exactly instances are started. I have two > > > applications running on GAE, one of them have billing enabled. The one > > > with billing enabled have been stress tested and have at most started > > > 100 simultaneous instances. The other is just for testing and staging > > > purposes and have never handeled much traffic. > > > > What I experience is that the staging server never starts more > > > instances than needed. If a single person views pages it will never > > > load more than a single instance. The other one however seems to start > > > about 5 instances before anyone can get hot responses, and it will > > > continue to start up to about 10 before realizing that ~1 QPS isn't > > > that much traffic (the requests finish in about 100ms each). > > > > So, why does GAE boot up lots of instances even though 1 instance can > > > serve the incoming traffic without a problem (the requests doesn't > > > even overlap, so no waiting is needed)? > > > > I realize that this isn't a very big issue, since when it gets lots of > > > traffic it will indeed need all the instances. I'm just curious why it > > > happens. -- 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.
