Bogdan,

That had occurred to me as well. I have verified testing locally that when 
successful the value is printed in the log. I have also verified manually on 
the system with the error that the key does exist in the cache, but the value 
in the cache is empty, just as in the log. That is what I believe is causing 
the failure, the lookup from the cache is successful (the key exists) but the 
value is empty, so OpenSIPS cannot route.

I have attempted increasing the logging on the system, but it appears the 
dns_cache module does not log anything further of use.

Ben Newlin

From: Bogdan-Andrei Iancu <bog...@opensips.org>
Date: Friday, December 7, 2018 at 12:21 PM
To: OpenSIPS users mailling list <users@lists.opensips.org>, Ben Newlin 
<ben.new...@genesys.com>
Subject: Re: [OpenSIPS-Users] DNS Cache module

Hi Ben,

IMO, the log itself is broken as the data to be cached is not printable ....so 
the logs you see may be misleading.

When you say "OpenSIPS appeared to not be able to resolve the domain", you mean 
OpenSIPS is not doing any attempt to solve the FQDN, or you mean OpenSIPS is 
loading from cash something wrong ?

Regards,


Bogdan-Andrei Iancu



OpenSIPS Founder and Developer

  https://www.opensips-solutions.com<https://www.opensips-solutions.com>

OpenSIPS Summit 2019

  
https://www.opensips.org/events/Summit-2019Amsterdam/<https://www.opensips.org/events/Summit-2019Amsterdam/>
On 12/06/2018 10:17 PM, Ben Newlin wrote:
Hello,

We use the DNS cache module to reduce the time spent querying DNS records. We 
recently had a customer call failing and we traced the failure to the customer 
using an FQDN in the Record-Route header. On the ACK, OpenSIPS appeared to not 
be able to resolve the domain even though it had been successfully resolved on 
the initial request. I found the log for the DNS Cache module and noticed that 
the value it was inserting was empty:

INFO:dns_cache:put_dnscache_value: putting key [dnscache_customer.domain.com_a] 
with value [] ttl = 60

This prompted me to examine all of our logs and I found that the value for 
these DNS Cache logs is always empty, regardless of the domain. It appears the 
records are not being serialized properly into the cache.

The DNS resolution must be succeeding or all of our requests using DNS would be 
failing, but I have also verified the domains all can be resolved manually on 
the same box:

$ nslookup customer.domain.com
Server:       10.27.0.2
Address:      10.27.0.2#53

Non-authoritative answer:
Name:  customer.domain.com
Address: 10.27.172.132
Name:  customer.domain.com
Address: 10.27.192.211
Name:  customer.domain.com
Address: 10.27.255.53

Any thoughts? Is there more information I can obtain to determine the cause?

Ben Newlin




_______________________________________________

Users mailing list

Users@lists.opensips.org<mailto:Users@lists.opensips.org>

http://lists.opensips.org/cgi-bin/mailman/listinfo/users<http://lists.opensips.org/cgi-bin/mailman/listinfo/users>


_______________________________________________
Users mailing list
Users@lists.opensips.org
http://lists.opensips.org/cgi-bin/mailman/listinfo/users

Reply via email to