[Pdns-users] PowerDNS Auth is slow on control socket

[Klaus Darilion]

Hi!

We use the PowerDNS Auth control socket with TCP from another host
extensivly to trigger "retrieve" requests. Several times a day we get
the follwing error:

# pdns_control --remote-address=... --remote-port=... --secret=...
retrieve example.com
Timeout error: Error from remote in receive(): Resource temporarily
unavailable

I analyzed the problem with tcpdump and following happens:

* pdns_control established the TCP connection
* pdns_control sends the secret and the command
* 7 seconds later pdns_control gives up waiting and closes the TCP
conenction (FIN)
* another 1 second later the server responses with "Added retrieval
request ...."

Hence, the problem is that PowerDNS is sometimes very slow adding the
retrieval request.

Do you have an idea why this happens? Are there some internal locks? Any
ideas how to debug this to find the problem for the slow reaction?

This PowerDNS instance is well loaded (having almost 1Mio slave zones)

Thanks
Klaus