Questions regarding to "rndc stats"

[DavidWang@UoGuelph]

Hi all,
The statistics dumped out by "rndc stats", like:

*+++ Statistics Dump +++ (1140627000)
success 10267253
referral 51147
nxrrset 2002275
nxdomain 4189855
recursion 6693316
failure 1353103
--- Statistics Dump --- (1140627000)*
**
what's exactly each item means? does "success" mean all success queries
including all income and outgoing queries?

thanks,

David Wang