understanding slave debug

[jeffrey j donovan]

Greetings

I have an older slave server, I was checking the logs an when I put into debug mode it reports over and over again
14-Mar-2011 22:41:39.913 refresh_callback: zone 13.150.10.in-addr.arpa/IN/com.basd.DNS.private: enter
14-Mar-2011 22:41:39.913 refresh_callback: zone 13.150.10.in-addr.arpa/IN/com.basd.DNS.private: serial: new 2011011402, old 2011011402


for all of the zones. this is just one line. I have not changed any of the entry's on the master although I did issue a reload from both.

since the serial number has not been changed, no changes are taking place,  Im assuming this is normal logging behavior when in debug mode, is that correct?
-j