jan damborsky wrote: > Hi Dave, > > > On 02/19/09 22:48, Dave Miner wrote: >> A couple of comments in-line: >> >> jan damborsky wrote: >>> Hi Sundar, >>> >>> I have been thinking about support for unicast DNS part (section 1.2) >>> and it seems we would need to provide option for specifying DNS >>> domain for unicast DNS, since DNS server might reside in different >>> domain than AI server, for instance >>> >>> # installadm create-service [-u domain] ... >>> >>> '-u' would be optional and its presence would determine if unicast >>> DNS is to be used. If not provided, unicast DNS wouldn't be taken >>> into account. >>> >>> I am then thinking if this API enhancement might be sufficient >>> for incoming release - additional options might not be needed >>> for now with respect to support for unicast DNS and introducing >>> fallback mechanism (when neither unicast nor multicast DNS is >>> available). >>> >>> Behavior of AI server and AI client might be following: >>> >>> AI server - installadm create-service >>> ------------------------------------- >>> >>> * if '-u domain' provided, create service with support for unicast DNS, >>> display appropriate PTR & SRV records which need to be added to DNS >>> database >>> >>> * if multicast DNS available, register the service using multicast DNS. >>> Otherwise inform user that multicast DNS feature is not avialable. >>> >>> * add appropriate options specifying service location to configuration >>> files (menu.lst, install.conf) for fallback mechanism >>> >>> AI client behavior during service discovery phase >>> ------------------------------------------------- >>> >>> * if service unicast DNS domain provided, look up service using >>> unicast DNS. DNS domain would be specified as another option in >>> configuration file (menu.lst or install.conf), not determined >>> from DHCP DNSdmain option, since this might be different, something >>> like >>> >>> install_service=_install_service_64501,install_service_domain=ai_caiman.org >>> >>> >> >> It appears that you'd be forcing a domain to be specified and stored >> in the configuration file in all cases, which seems unnecessary; if >> the site wants to place the records in the standard domain, why >> shouldn't we use DNSdmain when an override is not supplied? > > That is a good point. If user doesn't specify domain (or specify > default), then > DNSdmain would be picked up: > > * default (pick up the one from DNSdmain): > install_service_domain=default > > * user specified > install_service_domain=ai-caiman.org. > > Presence of 'install_service_domain' option would let AI client > know that unicast DNS should be used. > In order to avoid potential confusion, trailing '.' would indicate > that install_service_domain contains DNS domain name. >
Rather than inferring use of unicast based on domain presence/absence, I would suggest an option explicitly specifying that it be used, and make the absence of the domain specifier indicate the default DNS domain should be used. Dave
