And yeah, just before anybody got frightened by my latencies--I'm in the middle of Siberia. It's about speed of light[1], actually. It's not so fast.
[1] http://www.igvita.com/2012/07/19/latency-the-new-web-performance-bottleneck/ On Tue, Jan 29, 2013 at 4:13 AM, Igor Kharin <[email protected]> wrote: > Since what I care is latency, protocol overhead is insignificant in my case. > It's odd, but is the best measure so far. > > As ghs.* gets resolved to the nearest DC (which in my case is EU one) > requests are "piped" throught it to App Engine servers. This EU-DC > US-DC > > EU-DC thing is what makes apps slow to European users. > > As an illustration: > $ ping ghs.google.com > PING ghs.l.google.com (173.194.71.121) 56(84) bytes of data. > 64 bytes from lb-in-f121.1e100.net (173.194.71.121): icmp_req=1 ttl=44 > time=90.2 ms > $ time wget http://$GAEAPP/ > ... > real 0m0.756s > user 0m0.008s > sys 0m0.004s > $ time wget http://$GAEAPP/ > ... > real 0m0.198s > user 0m0.000s > sys 0m0.004s > > In last "wget" page got egde-cached (served from EU front-end) while > 250-800+ ms is an "actual" latency to the app (paid, zero traffic, resident > instance). > > P.S: Have you tried to post your question on StackOverflow? > > > On Tue, Jan 29, 2013 at 2:33 AM, alex <[email protected]> wrote: >> >> Hey Igor, >> >> I'm not sure what you mean: ping and wget really use different >> protocols so it's probably not a fair comparison. Plus, AFAIK >> ghs.google.com and ghs.googlehosted.com resolve to different IPs based >> on your location (correct me if I'm wrong), so this too wouldn't be >> fair. And another thing is, myapp.appspot.com is usually a CNAME to >> ghs.google.com, googlehosted.com or similar (at least, in my setup), >> so myapp.appspot.com and ghs.google.com is the same thing. >> >> On Mon, Jan 14, 2013 at 11:07 PM, Igor Kharin <[email protected]> >> wrote: >> > Oh, lucky you! Does it feels, well, less crowded there? :) >> > >> > And more importantly, what are latencies? Like, approximately, what's >> > the delta between "ping ghs.google.com" and "time wget http://$EUAPP";? >> > From what I see with edge-cached pages it might be around 30+ ms. >> > >> > Thanks. >> > >> > On Mon, Jan 14, 2013 at 9:12 PM, alex <[email protected]> wrote: >> >> I've been playing around with an app hosted on EU datacenters for the >> >> past few days and I've gotta say it's been a freaking awesome >> >> experience so far, especially for what concerns latency. >> >> >> >> It's been so great that I think we'll go live next month with this app. >> >> There's one thing I'm not sure of: it's a TT program as far I as can >> >> tell so, when there's an issue does one create it as usually on the >> >> issue tracker, even if it's a production one? >> >> >> >> For instance, there's something weird going on with the memcache >> >> service right now, it shows all 0 and says "Could not retrieve >> >> statistics. Try again shortly." >> >> >> >> thanks. >> >> >> >> -- >> >> 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. >> >> >> > >> > -- >> > 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. >> > >> >> -- >> 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]. >> Visit this group at http://groups.google.com/group/google-appengine?hl=en. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> -- 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]. Visit this group at http://groups.google.com/group/google-appengine?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
