DNSTAP doesn't purge old dnstap files

[Jesus Cea]

Hi everybody.

Bind 9.16 here.

I have this configuration for DNSTAP:

"""
   dnstap {auth; client; resolver; forwarder;};
   dnstap-output file "/var/cache/bind/dnstap.tap" size 100M versions 
100 suffix timestamp;
"""

The "dnstap.tap" is correctly moved to "dnstap.tap.TIMESTAMP" a new 
"dnstap.tap" file is created when the old one reaches 100MB in size, but 
bind is not purging old "dnstap.tap.TIMESTAMP" files when their count 
goes over 100. It doesn't delete all files at all.

I configured logging as:

"""
   channel dnstaplog {
     file "dnstap.log" versions 10 size 5m;
     print-time yes;
     print-category yes;
     severity debug;
     print-severity yes;
   };

   category dnstap { dnstaplog; };
"""

I only see in the logs when a new "dnstap.tap" file is created, but I 
don't see anything related to deleting old files, or errors trying to do so:

"""
...
21-Mar-2023 18:44:31.327 dnstap: info: rolling dnstap destination 
'/var/cache/bind/dnstap.tap'
21-Mar-2023 18:57:12.937 dnstap: info: rolling dnstap destination 
'/var/cache/bind/dnstap.tap'
21-Mar-2023 19:09:23.546 dnstap: info: rolling dnstap destination 
'/var/cache/bind/dnstap.tap'
...
"""

Any suggestion?

PS: Previously I was using "increment" instead of timestamped 
"dnstap.tap" files and it worked fine (well, reusing/overwriting old 
files, not deleting them).

-- 
Jesús Cea Avión                         _/_/      _/_/_/        _/_/_/
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