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 <nickmi...@gmail.com> 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 <tala...@gmail.com> 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 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.

Reply via email to