If the log entry for the image has a "referer" for a site page, then it is unlikely that the image is being served from another page/site (unless there is referer-based access control and someone *really* wants the image(s), so is mucking the referer). Apache doesn't write the log entry until the page has been delivered (otherwise it wouldn't be able to give you the number of bytes served). If your page(s) have something that keeps them from being fully served (js, and ad, etc.) then the user may click off the page before everything closes out and the entry is logged. I.e., this wouldn't require the user to explicitly abort the page delivery, they may just be doing it implicitly if the page has delivery issues. You should be able to check this fairly easily yourself. ------------ Original Message ------------ > Date: Thursday, April 02, 2015 20:00:00 -0400 > From: 5k Kate <5k.kate.1114@xxxxxxxxx> > > Is it possible that the image links are being shared separately > from the page? Theoretically someone could go and post your image > into another page. > > -Kate > > On Wed, Apr 1, 2015 at 1:09 PM, Andrew Moise > <andrew.moise@xxxxxxxxx> wrote: > >> Hello all. >> I'm trying to analyze the behavior of visitors to my web site by >> parsing my Apache access log, and it seems that the log is missing >> some entries. For example, it's happened before that there's an >> entry in the log for serving an image, with a referrer set to one >> of my HTML pages, but there is no entry in the log for that HTML >> page (either before or after the entry for the image loading) >> from any similar IP address. I don't think that the headers I'm >> emitting would cause the browser to cache that particular HTML >> page. >> Furthermore (and more to the point of why I'm concerned about >> this), parsing the apache log indicates a small fraction (maybe >> 25%) of the number of visitors indicated by a third party logging >> tool (in this case clicky.com). >> Is there anything that could cause this? For example, does >> apache not put an entry in the log if the connection is >> interrupted before the entire HTML file is emitted? >> Thanks in advance for your help. >> -Andrew >> >> ----------------------------------------------------------------- >> ---- To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx >> For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx >> >> ------------ End Original Message ------------ --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx