[collectd] ntpd plugin complaining [not FIXED yet]

[Florian Forster]

Hi again ;)

On Wed, Nov 01, 2006 at 09:00:07PM +0100, Lubo?? Stan??k wrote:
> I did the same modification on ntpd like you yesterday.
> The rest of the remark was that I got rid of the famous "getnameinfo
> failed: ai_family not supported" but I found out another problem.
> My .rrd directory contains files like (also time_dispersion and
> time_offset .rrd files):
> delay-::.rrd
> delay-::c021:0:100:0:9a99:9999.rrd
> delay-0:6e73::6e65:7400:7265:6e74.rrd
> delay-0.0.0.0.rrd
> delay-100::.rrd
> delay-119.121.0.0.rrd
> delay-::145.2.0.0.rrd

There are some really weird hosts in there :/

> Moreover the number of files increases.

You mean the number of files increases constantly? How many files per
hour, day or whatever reasonable do get created?

> The values "::" and "0.0.0.0" mean probably that the structure is zero
> filled.
Definitely.

> Some of them look like reference clocks. The rest seems to be some
> garbage. I would bet for a text in some of them.

Hm, the addresses used for reference clocks start with 0x7F7F or, in the
usual decimal notation, 127.127. These names should be resolved
correctly.

> So the conclusion is that you must do some fields validation procedure
> before processing IPV6 address.

I've double checked with `ntpdc's source: They don't do it.. I wonder
what they are doing different?

> First I thought that one of the servers returns the garbage.  I
> checked all of them one by one. No troubles with any of more than 30.
> Later I returned to the previous ntp.conf and the garbage appeared
> again.

So as long as you have only one server configured everything's fine? Did
you configure a specific server or the round-robin address?

> Nov  1 20:18:20 ls collectd[31163]: rrd_update failed:
>   ntpd/time_offset-::.rrd: illegal attempt to update using time
>   1162408699 when last update time is 1162408699 (minimum one second
>   step)

This most likely means, that more than one `host' with the address `::'
is being reported.

> It seems that the problem is caused by the combination of the RRD DNS
> servers .pool.ntp.org and ntpd server.

I'm using `pool.ntp.org' myself, and I usually configure between two and
three servers that are being chosen randomly at startup. I've never had
these issues so there's at least one additional factor.

> I have not found any information about ntpd's behavior in such case.
> But it seems it returns invalid information in the query response. It
> maybe prepares to switch the servers and returns partially filled
> structures.

The structures seem to be filled with random bytes, at least part of the
structures: They all seem to contain some null-bytes on either end of
the structure..

> I am sorry but I have not found a solution so far. I am glad that I
> have found the problem source.

Could you run the following two command and send their output? These
command essentially do what the plugin is doing - with and without name
translation:
  ntpdc -c peers
  ntpdc -n -c peers

Regards,
-octo
-- 
Florian octo Forster
Hacker in training
GnuPG: 0x91523C3D
http://verplant.org/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://mailman.verplant.org/pipermail/collectd/attachments/20061101/791e69be/attachment.pgp