[dnsdist] "Timeout from remote TCP client" with dnsdist + PDNS Recursor

[Christian Joffre Calva Urrego]

Hi everyone,

We currently use dnsdist 1.4 and have a PowerDNS Recursor configured as 
downstream server. Everything has a standard minimum configuration, with

..
client-tcp-timeout=60
..

configured on the PDNS Recursor.
The point is that in PDNS Recursor we can see the following entry log:

..
pdns_recursor: Timeout from remote TCP client <IP_DNSDIST>
..

We have been investigating and apparently the dnsdist does not close the 
TCP sessions with the configured downstream server (PDNS Recursor), 
having to close them the PDNS Recursor.

Is there a setting in dnsdist to set idle time of a TCP connection to a 
backend server?
What is the default lifetime of a TCP session in dnsdist, once it is 
waiting and not being used?

Thank you.
Kind regards,

Christian J. Calva