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. > > 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. > -- 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.
