My understanding (please correct me if I'm wrong) of the log time numbers
are:

1.) Latency time - the amount of actual real world time taken to process the
request. The App Engine infrastructure uses this time to determine if you
are (since it's Christmas time) being naughty or nice. Different numbers
have been thrown out as to what it means to be nice but definitely average
latency time needs to be under 1 second but it's been noted that sub 800ms
is preferred and even lower is better. What happens if you're naughty. Well,
then supposedly Santa won't spin up additional instances for you. It has
been noted on this forum by Santa's Elves (the Googlers) that this average
latency time requirement to spin up new instances doesn't include the
latency time for background tasks.

2.) CPU Time - the amount of CPU time that your code has used based on a 1.2
GHz 64-bit x86 CPU executing sequentially which equates to 1200 megacycles
equal to one second physical time. My assumption is then that if your code
executed on a 2.4 GHz machine that real world time could be 1 second and CPU
time could be 2 seconds (assuming no API time).

3.) API Time - the amount of API time. Time spent executing in API calls.
This number could be very large even even if Latency Time is small. For
example, performing a batch get of 200 keys. These could be executed in
parallel by the API and could result in large API time but small latency
time.

Now, according to the QuoteService docs, the CPU Time and API Time are
completely separate numbers and would need to be added together to get your
Total Billed CPU time. Now, do the logs follow this convention. I'm not
totally sure since I can't find the logs documented anywhere and I can't
find an example in my logs of API time ever being greater than CPU time. I
would assume that at times if I did a batch get like I mentioned above and
very little else in my code that the API time would greatly exceed my CPU
time, but I can't find that. It would be great if anyone can add to this and
if they have an example log entry showing this that would be awesome. Any of
Santa's elves wish to chime in? Also, if this is documented someplace nicely
and I just couldn't find it then a link to it would be nice.
Stephen


On Mon, Dec 6, 2010 at 7:52 AM, mscwd01 <mscw...@gmail.com> wrote:

> I always assumed the blue was cpu time and the red api time. Please
> feel free to correct me if I am wrong though.
>
> While we're on the topic of appstats does anyone get a zero value
> reported for cpu and api times? I only ever get readings such as this:
>
> real=774ms cpu=0ms api=0ms overhead=0ms
>
> Not helpful at all :P
>
>
> On Dec 6, 1:43 pm, Fredrik Bonander <carl.fredrik.bonan...@gmail.com>
> wrote:
> > In my application i saw something that kinda worries me a bit.
> >
> > In the logs for on specific request it takes 3275ms 9140cpu_ms
> 7296api_cpu_ms for the request to complete.  The request started a new
> process and saved the request to appstats.
> >
> > A typical request to the same URL generates for example this: 384ms
> 2306cpu_ms 1630api_cpu_ms in terms of time to process the request.
> >
> > Inspecting this a bit further I realized that in appstats the redbar is
> about 5 - 15 times as long as the blue.
> >
> > So my question what's the red and blue bars? In the log what's the
> difference between the first, second and third ms numbers?
> >
> > What numbers is withdrawn from my CPU quota ?
> >
> > ..fredrik
> >
> > --
> > Fredrik Bonander
> > carl.fredrik.bonan...@gmail.com
> > +46 70 943 5441
> >
> > - the infinite power of the creative mind -
>
> --
> 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<google-appengine%2bunsubscr...@googlegroups.com>
> .
> For more options, visit this group at
> http://groups.google.com/group/google-appengine?hl=en.
>
>

-- 
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