Thanks peterk.

We were doing this, however:

"Under this 1 request/second load, we are still seeing lots of
instance
startup - even after 40-50 minutes of sustained load. Subjectively,
the instance startups seem to come in bursts, though we've done no
formal analysis around this."

It sort of seems like a bug to me.

j

On Mar 12, 9:59 am, peterk <[email protected]> wrote:
> As cz suggested, you could set up a request handler that does a
> minimum of processing (i.e. one that just returns an empty response or
> something), and then ping it from a third party location frequently
> enough to keep your app hot.
>
> That would use up requests, but shouldn't burn too much cpu or
> bandwidth quota if the request handler is really doing virtually
> nothing.
>
> Then once you get enough natural traffic to keep your app hot you
> could stop doing this.
>
> If you don't want to, or can't, ping from a third party location,
> maybe you get your app to ping itself. 
> See:http://stage.vambenepe.com/archives/549
>
> On Mar 12, 2:57 pm, Jason C <[email protected]> wrote:
>
> > It's unfortunate the no one from Google has given a comment on this
> > thread (at least as far as I can tell).
>
> > Is this aggressive application restarting normal, or is it a bug?
>
> > Is there something/anything that we as developers can do with our
> > software to provide good responsiveness even on lower traffic / new
> > sites?
>
> > j
>
> > On Mar 11, 4:38 pm, johnP <[email protected]> wrote:
>
> > > That's an excellent point.  Can I assume that (if) I ever reach the
> > > billing limit, the cache will last longer than 2 seconds?
>
> > > On Mar 11, 11:00 am, peterh <[email protected]> wrote:
>
> > > > On Mar 11, 12:28 pm, johnP <[email protected]> wrote:
>
> > > > > I've been tracking (and seeing) this for a while already.  Besides the
> > > > > latency that occurs each time Django gets re-zipimported, what is
> > > > > concerning is the thought of paying for CPUs to constantly reload the
> > > > > cache.  My app's not live yet - so there is some time before this
> > > > > becomes a $$$ problem for me, but...
>
> > > > But how can you reach your billing limit if the issue is that you get
> > > > low traffic in the first place? other than that, I agree, it would be
> > > > great if this 2-sec limit was increased.
>
> > > > > I remain forever hopeful that it will be solved by then. :)
>
> > > > > On Mar 11, 4:26 am, Antonin Hildebrand <[email protected]>
> > > > > wrote:
>
> > > > > > I can also confirm this behavior with my app, recycling takes place
> > > > > > after about 2 seconds of inactivity. I also guess, that this 
> > > > > > recycling
> > > > > > timeout had to be lowered by GAE team during last week, because I 
> > > > > > had
> > > > > > running and working application on appspot. I did no updates to it 
> > > > > > and
> > > > > > the app did break because of this change.
>
> > > > > > On Mar 10, 6:22 pm, Jason C <[email protected]> wrote:
>
> > > > > > > We have a new application that receives _very_ little load. So 
> > > > > > > little,
> > > > > > > in fact, that each request spins up a new application instance. 
> > > > > > > We are
> > > > > > > using Django trunk and the import overhead is high. All of this 
> > > > > > > yields
> > > > > > > a long request (e.g., 8802ms) using a lot of CPU (e.g., 
> > > > > > > 3247ms-cpu).
>
> > > > > > > With very little load, it makes sense that instances are 
> > > > > > > recycled. On
> > > > > > > that assumption, we've started applying some primer load against a
> > > > > > > couple of uris in an attempt to keep some instances hot. We're
> > > > > > > applying around 1 request/second across 2 uris.
>
> > > > > > > When we hit a hot instance, we get blazing speed (e.g., url_1: 
> > > > > > > 73ms
> > > > > > > 91ms-cpu, url_2: 368ms 615ms-cpu - these values are pulled from 
> > > > > > > the
> > > > > > > App Engine console Logs tool and I'm not completely sure if this
> > > > > > > represents Runtime, or combined Runtime/API - I believe the 
> > > > > > > latter).
>
> > > > > > > Under this 1 request/second load, we are still seeing lots of 
> > > > > > > instance
> > > > > > > startup - even after 40-50 minutes of sustained load. 
> > > > > > > Subjectively,
> > > > > > > the instance startups seem to come in bursts, though we've done no
> > > > > > > formal analysis around this.
>
> > > > > > > Does anyone else see this behavior? It _really_ kills our 
> > > > > > > application
> > > > > > > performance - so much so, that we're considering moving away from
> > > > > > > Django in an effort to minimize the start-up pain.
>
> > > > > > > Any info or war stories would be appreciated.
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