<http://will.phase.net/phasedelay.png> Hi Cayden,
Thanks for your reply. I've been using Chrome to test the latency - I hit the page several times using both URLs and here are the results. These times are the delay between the request and the first response i.e. see attached image. https://phaseindustries.appspot.com/ -> 2a00:1450:400b:c00::8d 57ms 57ms 56ms 66ms 58ms 57ms AVG: 58.5ms https://www.phaseindustries.com/ -> 2a00:1450:400b:c00::79 484ms 385ms 195ms 183ms 451ms 201ms 216ms 394ms AVG: 313ms I ran the test python you enclosed and the results showed TCP connections to both nodes were equal: -->testtcp.py 0.0420000553131 seconds 0.039999961853 seconds I hope that helps describe my problem in more detail - my guess is perhaps it's the SNI lookup happening on the :79 node? Regards, Will On Thursday, July 19, 2012 5:34:08 AM UTC+1, Cayden Meyer wrote: > > Hi Will, > > There are potentially many causes of end-to-end latency in a request. > > During my testing I see roughly equal performance between appspot.com and > SSL on my custom domain. > > Are you able to exclude DNS as a source of the increased latency (retry a > few times to ensure the host is in your systems cache)? > > Is there a significant different in a straight TCP connection to each of > different addresses (see python code below)? > > SSL in general can add additional latency on top of a non-SSL connection > due to the initial multiple round trips associated with the SSL handshake. > > Thanks, > > Cayden Meyer > Product Manager, Google App Engine > > import socket > import time > def time_connect(*args, **kwargs): > sock = socket.socket() > start = time.time() > sock.connect(*args, **kwargs) > end = time.time() > print end - start, 'seconds' > time_connect(('www.appspot.com', 80)) > time_connect(('ghs.googlehosted.com <http://ghs.google.com/>', 80)) > > On 19 July 2012 05:02, Will (Phase Industries) wrote: > >> Hi, >> >> *Domain Name*: www.phaseindustries.com CNAME to ghs.googlehosted.com. >> *Users Affected*: all visiting the SNI endpoint >> *Problem Description*: I am using SSL certificate on SNI - so my domain >> is being served from ::79 (.121) IP and not ::8d (.141) which I get when >> using my corresponding *.appspot.com domain - and I am getting a >> 300-400ms performance hit through this. Since I am paying for the SSL >> endpoint, I wondered if this delay was expected? >> *Steps to Reproduce*: Using Chrome, visit the site over the SNI address >> (.121) and use the network developer tool to measure latency from request >> to response. Then visit on the *.appspot.com (.141) endpoint and notice >> that there is virtually no latency. >> >> Any chance of getting an answer if this is a known issue, potentially >> something to do with the SSL cert lookup when accessing an apps domain >> through the ::79 (.121)? >> >> Does not make any difference whether accessing over IPv6 or IPv4 but >> providing v6 since that's my primary access point. >> >> Cheers >> >> Will >> >> -- >> > -- 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/-/10BGF5CasKoJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
