Ok,

(a bit bummed that nobody bother to reply to my first post to the
group)
I spent the last few days reading related posts, transcripts of chats
with Marzia, went through the related tickets and still I have no
answer.

Let me try once more to explain my question:
It is not about quotas.
It is neither about performance per se.
My question is about cost.
My app implements a beacon service - my client websites that will be
using the beacon have 5-10M pageviews per month and these pageviews
will result into actual beacon hits to my app.
These requests do not hit the Datastore - I buffer them in memcached
doing minimal processing to keep the per beacon-hit cost low and
"process them" in batches every few seconds.

Still, in spite of all the buffering, if the cheapest write (1 attr
table, no indexes) gets charged 250-500msec, this make the app design
for such a high throughput service non-obvious.

I understand that I can decrease the number of my writes by using a
pickled blob attr that contains lots of records inside - that what I
am about to do.
I just wanted a confirmation from any gurus out there, or from the
google team that my understanding about the cost of the "cheapest
write" is correct.

I tried batch db.put( of 100 single cell objects) - still took 23
seconds of data store CPU , i.e. my cheapest write = 230msec - a bit
less than before but not by much.
I made all 100 objects children of same parent and performed the same
test - again same datastore CPU utilization

Is there another method to update/insert multiple records that costs
less? I.e. is there any cheaper write? ( I am very flexible :-) )
Is my understanding that the planned 10-12cents per CPU hr will be
applied towards the datastore CPU usage as well?

Thanks a lot,

diomedes


On Feb 14, 3:18 pm, diomedes <[email protected]> wrote:
> Hi all,
>
> I have a question with regards to the pricing and how it relates to
> the relatively high API CPU associated with each write (400-500msec)
>
> I have started working on my first GAE app about a month ago - and
> overall I am both excited and very satisfied.  My initial plan, was to
> run it on Amazon's EC2 - but eventually I took the plunge, started
> learning python, move to GAE and (almost) never looked back :-)
>
> My app, a cacti-like webservice that monitors the performance ( think
> response time) of a website using google analytics-like beacons, is
> rather resource demanding.  On top of that GAE best practices imply
> that any expensive reports/aggregates etc should be precalculated/
> stored instead of dynamically produced on demand.  All that result in
> many writes and given that the simplest write (single key-val pair, no
> indexes) gets "charged" approx 500msec of API cpu time (see related
> thread by 
> Matijahttp://groups.google.com/group/google-appengine/browse_thread/thread/...)
> a normal DB design that would have been meaningful in terms of cost on
> EC2 becomes impossible on GAE.
>
> Because I am a google-aholic I decided to change the app design to
> minimize writes - I fetch a bunch of pickled data as a blob,  update
> in mem and write them back as blob (just like people did before DBs
> came along :-) )
> Before I commit to that design I wanted to get the confirmation that
> my understanding is correct:
>     - Google is going to charge 10-12cents per CPU-hour and it will
> include in that all the CPU used from APIs etc. (http://
> googleappengine.blogspot.com/2008/05/announcing-open-signups-
> expected.html)
>     - This means that if your site does 10M pageviews a month and does
> a couple writes per pageview at 500msec per write it will be  "10M CPU
> secs/mo just from the writes, i.e. 10M/3600 * $.10/hr = $280/mo just
> from the writes.
>
> Is this correct?
>
> For the record, I find Google's planned pricing extremely attractive
> when compared to Amazon's primarily due to the fact that Amazon
> charges 10c for CPU-hr of the machine while google (will) charge 10c
> for CPU-hr *actually used* by your requests.  This makes a huge
> difference -- a server running at 50+% capacity (thats rather
> aggressive - but with Amazon/RightScale combination you can be
> aggressive) will still use less than 20% of its CPU during that time.
> However, when comparing the cost writes  between Google and the
> corresponding setup of a [high CPU EC2 server + elastic storage] combo
> (able to provide quite more than  20-50 "simple" writes per sec)
> Amazon is much cheaper than Google.
>
> Ok, that's all I had to say,
> Sorry for the rather long post,
> Looking forward to hear comments
>
> Ah and thank you very very much for lifting the high cpu quota!!
>
> Diomedes
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