On Wed, Jun 13, 2012 at 2:26 PM, Brandon Wirtz <[email protected]> wrote: >> These numbers tell you how much a request cost, but don't tell you how >> much another identical request will cost. > > The variance between my "identical" requests is less than 10%.
Only when GAE is behaving normally. As the OP pointed out, this can vary by a factor of 2-6+ for days at a time. > In relation to multi-threading, I only see a variance on the downside of a > Spike, when I have Idle instances. That seems to be less than 10% as well. > If you have lots of idle threads raising your price you aren't optimizing > your Defer Queue and steady state tasks effectively. > > We have seen AWS days where cluster congestion has raised our bills by 3-4x > using a Specified QoS based on "latency"/time per request/request queue > depth. (same as tuning the scheduler). Sure. However, GAE seems to be particularly sensitive to this issue because of low concurrency limits. > As always the people who are complaining don't seem to understand how the > Scheduler works (which is quite likely a fault in Google's > Documentation/lack there of). You either pay for QoS that is X, or you say > your users can have a crappy experience, and Latency won't make a lick of > difference in your App. > > My biggest charge days are not days that "latency" spikes but days that > MemCache gets slow, or seems to "dump" more often than expected. This > hasn't been enough of an issue for us to implement our own Memcacher as a > Backend primarily because we are using 10+ gigs of memcache and can't build > an instance to do that. Sure... and you probably wouldn't want to either given how insanely expensive backend RAM is on GAE. But your app is a bit of an oddity, and fits into a quirk of GAE's pricing model. You primarily consume two resources that Google doesn't charge for - memcache and edge caching. This is is highly atypical. Jeff -- 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.
