On Fri, Jul 20, 2012 at 7:10 AM, hyperflame <[email protected]> wrote:
> On Thursday, July 19, 2012 2:57:28 AM UTC-5, Richard Watson wrote: >> >> >> That's fine, but all we're asking for is "don't dump those requests into >> an instance that isn't able to serve the request immediately". If there >> are three instances running and one being started up, don't consider the >> latter in the population of instances to send requests to. Dump it into an >> instance level queue that is already running. Everything else remains >> constant. >> > > Let's back up a minute here. To the GAE scheduler, as it is right now, > there is no concept of "starting up." Either there is an instance, or there > is no instance. A "cold" instance is just as good as an instance that has > been active for hours. > > If you read Mr. Matsuo of the GAE team's posting, he wrote, "If you have > an app with average +50s loading time, I totally understand that you > strongly want to avoid sending requests to cold instances. On the other > hand, there are also many well-behaved apps with <5 secs loading/warming > time. Please understand that for those apps, it is still acceptable if we > send requests to cold instances, so it's likely we can not prioritize the > feature bellow over other things, however..." > > I read that as (and correct me if I'm wrong) that the GAE scheduler > expects cold instances to be ready in less than 5 seconds (notice the > "well-behaved" remark). If that is so, there is no reason to categorize > instances as being in "starting up" phase. An instance is an instance is an > instance, regardless of whether or not it was just cold-started. > > Let's go back to the MegaWalmart example. MegaWalmart is guaranteeing that > if it opens a new checkout lane, that checkout lane will be open quickly, > that the clerk will not be drunk, the scanner will be working, etc. Is that > guarantee reasonable? That's the point of this thread. > > > On Thursday, July 19, 2012 2:57:28 AM UTC-5, Richard Watson wrote: >> I stand to be corrected, but I doubt that Google searches are dumped onto >> cold instances. >> > > The GAE scheduler expects hosted apps to cold start in less than 5 > seconds. If the GAE scheduler expects that of us, I don't see why Google > wouldn't hold itself to that same commitment. > To clarify, there is no any hard limit on the cold startup time except for the hard deadline(60secs for online, 600secs for offline). The 5secs just came from Jeff's e-mail I think. That said, it is one of the most important best practice with App Engine to reduce the loading time. At the same time, we understand that some people want to use popular Java libraries which take longer to load. We're trying hard to mitigate the pain by fastening the loading time, it's underway, but no ETA yet. So for a time being, I would suggest setting sufficient number of min idle instances to reduce the number of user-facing loading requests, especially if you think your app is important and you strongly want to eliminate the user-facing loading requests. Additionally, we started an internal discussion about reviving warmup requests for dynamic instances. If you want this feature, please star the following issue: http://code.google.com/p/googleappengine/issues/detail?id=7865 -- Takashi > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/google-appengine/-/nwb8Q4Bxx7cJ. > > 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. > -- Takashi Matsuo -- 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.
