Hi Igor, I have followed your advice and set max latency to auto and min idle instance to 1 :
<https://lh6.googleusercontent.com/-XTTg4ebm-mY/UKg0XDUdozI/AAAAAAAAwO8/V--InrAlRGc/s1600/Application+Settings+-+VinoCities+-+Google+Chrome.jpg> I'll tell you how it goes. Thanx again for your help. François On Saturday, November 17, 2012 10:50:07 PM UTC+1, Igor Kharin wrote: > > You are right. That's precisely why I said "somehow" there--scheduler can > go wrong. Maybe the app had a little spike for a sec or it's really just > tablet your instance were running on had a little hiccup. Actually, it > seems like old instance were plain dead to scheduler for a while. > > Here it starts to be interesting, even though we had max latency = 15s and > new instances with 20s latency were ineligible, it only started like > three instances until the scheduler figured out that it doesn't help and > decided to fed requests to existing ones. Then performance settings come > into the game: as scheduler "somehow" found instance to be slow it was > trying to use new, "hotter" instances (screenshots 3-4) and nicely sent > only two request to the old one. And since we haven't explicitly stated how > much idle instances we want, the scheduler might have guessed (albeit, > mistakenly) -- OK, this app needs two instances right now. > > Just my speculative optimistic assumptions, but it's kind of remarkable. > It'd be cool if the scheduler did improve that much. I've had worst: > absolutely no traffic other than me, yet new instances were spinning off > with no apparent reason. The issue have disappeared within a couple days. I > am to wordy again, so: try to set max latency to auto, plus add a resident > instance for a while. Even if problem stays, it should keep scheduler from > running new instances. > > > On Sun, Nov 18, 2012 at 2:49 AM, Francois Masurel > <[email protected]<javascript:> > > wrote: > >> Hi Igor, >> >> Thanx for your nice and long answer. I understand and I'm ok with most >> of what you said. >> >> The only thing that annoys me is that my app is a Java app with threading >> enabled and as you can see on the screenshots the main long-lived active >> instance doesn't do anything : extremely low latency and almost no traffic >> served (no traffic at all between second and third screenshot). >> >> So, no, the active instance's queue is not full unless everything goes >> nowhere or the dashboard requests count is wrong. >> >> What do you think ? >> >> Thanx again for your help. >> >> François >> >> PS: >> >> And without changing any settings everything has been working fine for >> months. >> >> >> On Saturday, November 17, 2012 6:23:36 PM UTC+1, Igor Kharin wrote: >> >>> I've seen such pattern with my apps. As far as I can see, I believe, >>> this is perfectly OK given your performance settings. >>> >>> Somehow your active instance's "queue" was full and scheduler decided to >>> start a new instance. Since it was trying to serve the request for 20 >>> seconds, and again, given your settings (max latency = 15s), scheduler >>> found it bad and kept trying to send requests to the old instance. And >>> again. And again. >>> >>> There are like exactly two safe options for performance settings: >>> 1. min idle instances = auto, max = 1, and a fairly high min latency >>> (low cost); >>> 2. min idle instances = 1+, max = auto (traffic spike); >>> >>> Generally, AE engineers recommend not to mix "min" and "max" options and >>> always set the opposite slider to "auto", as settings like in your case >>> (min latency = 10s, max = 15s) confuse scheduler's heuristics. My >>> advice would be to set "max pending latency" to auto and see what happens. >>> Then tune the "idle instances" setting as desired: >>> 1. max idle instances = 1 so you wouldn't pay for surplus instances; >>> 2. OR set min idle instances to 1+ as you obviously seeing a little >>> spike. >>> >>> Also, keep in mind that resident instances are not really what we had >>> with Always On--treat them as "fallback instances". To wrap up, in your >>> case, if you want to keep users off of startup requests completely (20s is >>> no good): >>> 1. set up a cron "ping" task to keep your dynamic instance "warm"; >>> 2. set min idle instances to 1 (do not forget to handle warmup requests); >>> 3. tune latency settings (say, min = auto, max = 1s to try to evenly >>> distribute load between resident and dynamic instances); >>> >>> Hope that'll help. >>> >>> >>> On Sat, Nov 17, 2012 at 10:44 PM, Francois Masurel <[email protected]>wrote: >>> >>>> It looks like old instances cannot serve any new coming requests : >>>> >>>> <https://lh4.googleusercontent.com/-aWdte4xv3WM/UKeuUzRBLjI/AAAAAAAAwOM/90Ii-6MyXbI/s1600/Instances+-+VinoCities+-+Google+Chrome_2.jpg> >>>> >>>> >>>> <https://lh5.googleusercontent.com/-XvW9NIfFJr4/UKeu5W-8-PI/AAAAAAAAwOU/RANrlkjySt4/s1600/Instances+-+VinoCities+-+Google+Chrome.jpg> >>>> >>>> >>>> <https://lh4.googleusercontent.com/-LnT3CjB47Cg/UKevT68Rt8I/AAAAAAAAwOc/ITOjbF_wzF0/s1600/Instances+-+VinoCities+-+Google+Chrome_3.jpg> >>>> >>>> >>>> <https://lh5.googleusercontent.com/-U6MzMOBSMho/UKewNjofMkI/AAAAAAAAwOs/Hc4nw1NW8ro/s1600/Instances+-+VinoCities+-+Google+Chrome.jpg> >>>> >>>> Looks like GAE send almost all traffic to the new instance which is not >>>> fully initialized (lazy loading). >>>> >>>> App Id : vncts1 >>>> >>>> On Saturday, November 17, 2012 4:21:28 PM UTC+1, Francois Masurel wrote: >>>> >>>>> I've notice lots of user facing loading requests since a few hours >>>>> (days?). >>>>> >>>>> Just check the screenshot below. Two new instances have been started >>>>> to serve only 13 (12 + 1) requests though another instance was already >>>>> running and available and obviously was not overloaded as it had only >>>>> served 105 requests during the last hour : >>>>> >>>>> >>>>> <https://lh4.googleusercontent.com/-UxI0M8fnvw0/UKep9Wkb_VI/AAAAAAAAwN0/wxKaPhZvXlI/s1600/Instances+-+VinoCities+-+Google+Chrome.jpg> >>>>> >>>>> My application instance settings are all set to automatic and pending >>>>> latency set to 10s : >>>>> >>>>> >>>>> <https://lh4.googleusercontent.com/-TxgVTyTvqJM/UKeqaNNQvBI/AAAAAAAAwN8/fKUP3ftluk8/s1600/Application+Settings+-+VinoCities+-+Google+Chrome.jpg> >>>>> >>>>> Did something change on GAE side recently ? >>>>> >>>>> These user facing loading requests are really killing my business as >>>>> my users are getting really upset about it. >>>>> >>>>> Thanx for your help. >>>>> >>>>> François >>>>> >>>>> App Id = vncts1 >>>>> >>>> -- >>>> 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/-/**ylBW4ldXw_cJ<https://groups.google.com/d/msg/google-appengine/-/ylBW4ldXw_cJ> >>>> . >>>> >>>> To post to this group, send email to google-a...@googlegroups.**com. >>>> To unsubscribe from this group, send email to google-appengi...@** >>>> googlegroups.com. >>>> >>>> For more options, visit this group at http://groups.google.com/** >>>> group/google-appengine?hl=en<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 view this discussion on the web visit >> https://groups.google.com/d/msg/google-appengine/-/uErXDY8EB9UJ. >> >> To post to this group, send email to >> [email protected]<javascript:> >> . >> To unsubscribe from this group, send email to >> [email protected] <javascript:>. >> 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. 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