Service Registries at the DNS Level

During the OCKHAM Registry Experiment meeting held in Seattle, USA, on 16-17 January 2007, there was some discussion about the possibility and practicalities of implementing a service registry at the DNS level.

This could be based on the technology used by Zeroconf/Bonjour (http://en.wikipedia.org/wiki/Zeroconf). If this is enabled with a service discovery mechanism, it allows for dynamic connection to services. Zeroconf is utilised by iTunes to automate music sharing by users who are on the same sub-net. RFC 2782 (http://tools.ietf.org/html/rfc2782) specifies fields in DNS records, which if set can enable automatic discovery of suitable services of a particular type.

At the meeting Dan Chudnov was quickly able to set up a demo of this in action, using some service data records he'd gathered from IESR via OAI-PMH.

Clearly developments at the DNS level are complementary to initiatives like IESR and OCKHAM. It allows for discovery of services that implement a particular protocol or serve a particular function. IESR's `transactional services' probably include those that would lend themselves to `low level' service discovery. But it doesn't seem to me possible to use this method to implement use scenarios that are based on discovery via IESR's and OCKHAM's rich collection descriptions, i.e. discovery of `informational services'.

Experiments of low level service discovery are outside of IESR's scope, but it seems to me they are worth pursuing. Maybe this area would make a good student project for someone somehwere.