Re: Some servvices on my edge box slow to reply

From: clvrmnky (clvrmnky-uunet_at_coldmail.com.invalid)
Date: 09/22/04 

Date: Tue, 21 Sep 2004 19:44:29 -0400

On 21/09/2004 7:02 PM, Dave Uhring wrote:

> On Tue, 21 Sep 2004 18:38:51 -0400, clvrmnky wrote:
>
>>Ok. The problem is that this has worked a treat until today. I've had
>>the same setup for years. I guess the lookups have just failed in a
>>timely manner until now, but I'd like to know /why/. And why only on
>>some virtual Apache instances? Why IMAP all of a sudden?
>
>
> Have you applied all released patches to the system, in particular patch
> 019?
>
I'm patched up to the limit for 3.1. I just checked the diffs in patch
19, and my source tree matches. I recall rebuilding named at some point.

>
>>Really? What else would it be? 10.0.0.254 is a valid static address
>>within 10.0.0 that I've given to the internal NIC. The resolver knows
>>about it via /etc/hosts. I've never needed to do a reverse lookup on it
>>before.
>
>
> nslookup does not use /etc/hosts; it uses only the designated
> nameserver(s).
>
True, but I've never had to care before. Obviously *something* outside
my realm of control has changed such that missed lookups are now taking
about 10x longer. This is completely new behaviour that I've never seen
in several years. I'm totally bewildered why some services would fail
*now*. Today. Some time since about 11PM last night.

I've been wracking my brains trying to remember if I tweaked anything.
I haven't. Nothing was changed, and that gives me some concern.

>
>>I have a caching-only nameserver, so I've done nothing extra other than
>>enabling that. I did the bare necessities out of the O'Reilly TCP/IP
>>book and the OBSD FAQs to get a cashing nameserver working, and have
>>never touched it since then.
>
>
> Did you configure a reverse lookup zone file? Are you using DDNS?
>
I'm not sure what DDNS is. Dynamic DNS? No. I have a static IP.

I have the localhost.rev file referenced in named.boot, but I'm not
acting as a primary nameserver right now. I know this is not strictly
correct, but it's all worked for years now. I've been meaning to be the
  primary DNS for internal hosts for some time (in fact, I have a
mydomain.rev file made, but commented out in the named.boot), but an
ultra-simple caching nameserver was good enough. I mean, lookups should
fail in some reasonable manner, and have done so until now.

The problem is I've never been able to figure out how to make a
nameserver that resolves for a set of internal nodes, but knows how to
go out to my secondaries and get external info. The instructions in the
FAQ never made any sense to me.

Of course, since the worst thing ('til now) that would happen is that
badly formed FQDNs would end up resolving back to my own IP address,
occasionally puzzling internal users.

>
>>I'm building new box to replace this one, which will be at 3.5.
>
>
> That will help. My published email address is valid and, if you wish, I
> will send you my actual config files for a DHCP/DDNS server which really
> works.
>
I am running DHCP. I have no idea what DDNS is. Dynamic DNS? DNS for
internal nodes only? I'll drop you a line, I guess. It's not like I
turned on DHCP and got this problem. I've been running it for years.
Up to now, there has been 0 problems opening a web browser and typing in
the static IP address that is the default httpd instance from a host
that happens to have 10.0.0.10. Same for any of the server aliases I have.

What is suddenly caring that 10.0.0.10 does not have an associated
hostname? It seems so arbitrary. I'd rather if it stayed broken and I
knew what the problem was. I'm not sure I want to throw more services
or tweaks at the problem.

Hell, if I kill BIND, everything will work again, it looks like.

> You don't really need much of a computer to perfom these services. I run
> mine on a K5/116MHz machine with 48MB memory and I have 15MB free.
>
I'm finding my P-133/80Mb system is getting too long in the tooth.
Mostly, I just want to bring my monthly kilowatt/hrs down, so I got a
VIA mainboard to play with.

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