> From: Stackpole, Chris [mailto:cstackp...@barbnet.com] > Sent: Monday, June 15, 2009 4:30 PM > Subject: DNS lookup problems after upgrade from Etch to Lenny > > Hey guys, > > I have been trying my best to figure this out recently but not having > much luck. I am hoping someone here might be able to help. > > We had an Etch box that had been running great for almost 2 years. When > we decided that we really should upgrade to Lenny, the box had over 300 > days of uptime. It was a really solid box that handled a ton of data for > us. > > There are a number of reasons, but we needed to update the system. So I > ran the upgrade process. I did an `apt-get update` and `apt-get upgrade` > on Etch, restarted, changed out sources to Lenny then did an `apt-get > dist-upgrade`. Standard and simple and everything seemed to go really > well. > > However, shortly after, it started slamming our DNS servers. It went > from an average of 3.5 requests per minute to over 7000 requests per > minute. Every time it talks to a system, it does a DNS lookup.
Scratch that bit. My network guy just sent me the official numbers. It jumped from 3.5 requests per minute to 73,955.25 requests per minute. A factor of 10 worse. :-0 > > At first I thought it was Apache and or the applications we run, but > after some testing, I don't think that is the case. I stopped all the > programs and apache before I started pinging other systems by their > domain name. It constantly asked the DNS for information. > > How do I know? I am running `tshark -f 'port 53'` and watching all the > data in real time. When I ping a name, it does a lookup. If I leave the > ping running, after a few seconds it asks again. I set up a loop using > `ping -c1` and no matter how fast the loop ran, it asked for the name > every time. > > So a busy server working with ~50 other computers and tons of > connections is asking the DNS for every connection! > > Can any one help out? I am digging around in all sorts of conf files but > not finding anything. My search online seems to suggest I should install > a DNS caching utility, but I don't understand why I have this problem. I > didn't have it before and on another system running a fresh build of > Lenny running the exact same software handling a similar load and its > DNS ask rate is just as low as it was on this system running Etch. > > I am at a loss. I appreciate any help people can give. > > Thanks, > Chris Stackpole > > > -- > To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact > listmas...@lists.debian.org > -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
