On Sun, 18 Apr 2010 10:08:23 -0400 Michael Gilbert <michael.s.gilb...@gmail.com> wrote:
> i suppose i am not able to reproduce it either. i see a modest amount > of dns queries when the page is first loaded, then more queries when > links are moused over. I have that too, the first time the mouse pointer touches a link to some website. I think we can agree that this DNS pre-resolution is an intentional feature. What I claim is a bug is this: > but i don't see the claimed activity for every pixel moved by the > mouse. -- except, strangely enough, if the mouse pointer moves along a link which has already been resolved once, no more DNS queries are generated. As soon as it ceases to touch any hyperlink at all, there is a continuous stream of DNS queries for every mouse movement event. Some thoughts: -- the domain name which is being queried seems to be literally "." (or perhaps even the null string). Naturally, the response from the DNS server is that this name cannot be resolved. -- suppose that WebKit, for some obscure reason, fails to distinguish between the cases that the mouse is hovering over a link with a hostname of ".", and that the mouse is not over any link at all. -- suppose further that WebKit fails to remember that "." is unresolvable, and queries it again every time it thinks the mouse is hovering over such a link. -- then the above-mentioned DNS pre-resolution will result in exactly the behavior that I've described, with the observed result that when the mouse is over an actual hyperlink which has already been resolved, the stream of DNS queries ceases. Confirmation -- consider the following HTML page: <html> <head> <style> a:hover { color: #00FF00 } </style> </head> <body> <h1>It works!</h1> <p>This is the default web page for this server.</p> <p>The web server software is running but no content has been added, yet.</p> <p> <a href="">null link</a> <a href="page.html">page.html</a> <a href="http://./">http://./</a> <a href="http://./page.html">http://./page.html</a> </p> </body> </html> When viewing this page (in Midori) as <http://127.0.0.1/index.html>, mouse movement over the non-link area of the page produces the usual DNS query storm. Movement over the first two links does not produce any DNS queries. However, movement over the second two links produces EXACTLY the same DNS storm as the non-link area. Strangely, when the page is viewed as <file:///var/www/index.html>, mouse movement over the hyperlinks or any other part of the page does not result in the DNS query storm. This still doesn't explain why you do not observe the same behavior. Maybe it depends on what kind of error gethostbyname(3) returns for the hostname "." . If so, then it might have something to do with the contents of the files /etc/{host.conf,resolv.conf,nsswitch.conf} . Here's mine; maybe you can reproduce the problem by using these: $ cat /etc/host.conf multi on order hosts,bind $ cat /etc/resolv.conf nameserver <NS1-IP-ADDR> nameserver <NS2-IP-ADDR> $ cat /etc/nsswitch.conf passwd: compat group: compat shadow: compat hosts: files dns networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org