[CentOS] differences in DNS between boxes
Les Mikesell
lesmikesell at gmail.com
Tue Aug 4 22:23:04 UTC 2009
Mike -- EMAIL IGNORED wrote:
> On Tue, 04 Aug 2009 21:31:22 +0200, Kai Schaetzl wrote:
>
>> Mike -- EMAIL IGNORED wrote on Tue, 4 Aug 2009 16:56:22 +0000 (UTC):
>>
>>> Please refer to my thread "excessive DNS slows httpd"
>> Why don't you keep posting in there then?
>
> Because the new title reflects a new focus, and I hoped
> to attract different people.
>
>>> Suggestions would be most welcome.
>> Foremost, you want to find out why those queries are generated despite
>> the fact that hostnamelookups are off. That is surely something in your
>> configuration or a web application. It's not a general problem of Apache
>> on CentOS, mine are all not doing that.
>>
>> Kai
>
> Until now, for a long time, mine wasn't doing it either.
>
> Part of the problem was suggested by someone on the Apache group;
> there are two problems:
>
> 1. Both boxes have nscd, but it was not running on the CentOS
> box. Now that I fixed that, all but the first connection
> are rapid, as you might expect.
>
> 2. We still do not why the change in httpd.conf caused the
> problem to appear. However, my belief that there was a
> difference between the two machines is accounted for
> by the difference in /etc/init.d/nscd . When I tried it
> for the first time this morning, the box that previously
> been fast was slow. No doubt, the nscd storage had
> timed out.
>
> Except that nscd was not set to run, it is probably not
> specifically a CentOS problem. Perhaps I made a wrong
> choice in setup?
If I really want to know what is different between two boxes, I'll do
something like NFS mount one into the other or rsync their /etc trees
somewhere on a common host and let diff -r walk through them.
Are you sure this isn't as simple as having (and using, check your
resolv.conf) a caching name server running on one box so most lookups
are resolved locally while the other is making the query to something slow?
--
Les Mikesell
lesmikesell at gmail.com
More information about the CentOS
mailing list