[Pdns-users] resource-limits metrics

Christoph cm at appliedprivacy.net
Sun Oct 24 16:43:59 UTC 2021

Hi Remi,

Remi Gacogne wrote:
> This counter is increased when we encounter a network issue that does 
> not seem to be caused by the remote end but by a problem on our side, 
> like if the recursor runs out of file descriptors or if we don't have a 
> network route to contact a given IP address, for example.

Thank you for this description, this helps me digging deeper.

pdns_recursor_fd_usage shows values bellow 200 and the default file 
descriptor limit is at 16k, so file descriptors should not be the root 
cause if pdns_recursor_fd_usage show the used file descriptors.

I made a PR to add fd-usage to the docs:

and your description for resource-limits:

so this is answered in the docs when the next person asks the same
question as I had.


from the logs when Recursor starts:

pdns_recursor: Insufficient number of filedescriptors available for 
max-mthreads*threads setting! (16384 < 16409), reducing max-mthreads to 2044

With 8 threads and max-mthreads at the default value (2048)
this should be:
2048 * 8 = 16384
Are the extra 25 (16409-16384) the basics that recursor needs by default?

best regards,

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