DNSTAP output file rolling trouble in BIND 9.12.0rc1
Alan Clegg
alan at clegg.com
Tue Jan 2 20:30:19 UTC 2018
Looks like something that ISC would like to have logged as a bug... And
a perfect thing to find in rc1. 8-)
AlanC
On 1/2/18 3:00 PM, Jay Ford wrote:
> I'm having some odd trouble with DNSTAP output file rolling in BIND
> 9.12.0rc1.
>
> I have named built like:
> BIND 9.12.0rc1 <id:f9c3aba>
> running on Linux x86_64 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt25-1
> (2016-03-06)
> built by make with 'STD_CDEFINES=-DISC_FACILITY=LOG_LOCAL5'
> '--libdir=/usr/lib/x86_64-linux-gnu' '--with-openssl' '--enable-dnstap'
> '--enable-fixed-rrset' '--disable-openssl-version-check'
> '--with-libtool' '--enable-dnsrps'
> compiled by GCC 6.3.0 20170516
> compiled with OpenSSL version: OpenSSL 1.1.0f 25 May 2017
> linked to OpenSSL version: OpenSSL 1.1.0f 25 May 2017
> compiled with libxml2 version: 2.9.4
> linked to libxml2 version: 20904
> threads support is enabled
>
> I have DNSTAP configured like:
> dnstap {
> client query;
> };
> dnstap-output file "tmp/dnstap.out" versions 10 size 10m;
>
> It mostly works as expected, except that named:
> o logs twice about rolling the file every time, such as:
> Jan 2 05:15:42 named[24758]: dnstap: info: rolling dnstap
> destination 'tmp/dnstap.out'
> Jan 2 05:15:42 named[24758]: dnstap: info: rolling dnstap
> destination 'tmp/dnstap.out'
> o sometimes crashes after logging that, possibly after rolling the file
> o writes to multiple output files simultaneously, such as:
> ls -lt dnstap* | head -2
> -rw-r--r-- 1 bind bind 1282048 Jan 2 16:24 dnstap.out
> -rw-r--r-- 1 bind bind 1273856 Jan 2 16:24 dnstap.out.0
> & 2 minutes later:
> ls -lt dnstap* | head -2
> -rw-r--r-- 1 bind bind 1286144 Jan 2 16:26 dnstap.out
> -rw-r--r-- 1 bind bind 1277952 Jan 2 16:26 dnstap.out.0
>
> This system had 4 worker threads in use. Another similar system with
> only 1 thread does not have such trouble, which got me wondering about
> problems with threads & DNSTAP, specifically output file rolling.
> Reducing the threads on the afflicted system (via named option "-n 1")
> seems to avoid the problem, but it's a little early to tell, & it's not
> a desirable fix.
>
> I'd appreciate it if somebody who knows the code would comment on the
> threads vs DNSTAP possibility or point me in some other direction to
> figure this out.
>
> I have a named core file & can provide more config... details if required.
>
> ________________________________________________________________________
> Jay Ford, Network Engineering Group, Information Technology Services
> University of Iowa, Iowa City, IA 52242
> _______________________________________________
> Please visit https://lists.isc.org/mailman/listinfo/bind-users to
> unsubscribe from this list
>
> bind-users mailing list
> bind-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/bind-users
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 874 bytes
Desc: OpenPGP digital signature
URL: <https://lists.isc.org/pipermail/bind-users/attachments/20180102/c1ba5135/attachment.bin>
More information about the bind-users
mailing list