Dave Miner wrote:
> 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.

That is better. I am thinking about following option to enable unicast DNS:

install_udns=[enable|true]

Jan


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