RE: Arlib ResolverTracing on opendkim-2.3.1 shows identical queries

> -----Original Message-----
> From: opendkim-dev-bounce_at_lists.opendkim.org [mailto:opendkim-dev-bounce_at_lists.opendkim.org] On Behalf Of Gary Mills
> Sent: Wednesday, March 30, 2011 7:08 AM
> To: opendkim-dev_at_lists.opendkim.org
> Subject: Arlib ResolverTracing on opendkim-2.3.1 shows identical
> queries
>
> I noticed that a ResolverTracing option was available with
> opendkim-2.3.1 so I decided to test it. I get about 50 debug lines
> for each e-mail message. Most of it looks reasonable, but I did
> notice that the filter made three identical DNS queries for a single
> e-mail message. I saw the same thing with a locally-originated
> message and an external one.
>
> Is this normal and expected, or is something wrong? If it's normal,
> perhaps a cache would improve performance. Here are the syslog lines
> for a local message:
> [...]

It's normal. It's an implementation of ADSP, which requires a check for domain existence by trying to get A, AAAA or MX records (hence three queries). Right after that you'll see the _adsp._domainkey.<domain> query.

They are launched in parallel to keep total time consumed to a minimum, but they're all required; ADSP says the only way to be sure a domain doesn't exist (for ADSP purposes) is to ensure that none of those three record types is present.

This isn't specific to arlib. Those queries are done with any resolver.
Received on Wed Mar 30 2011 - 14:51:25 PST