RESTful DNS services?

RESTful DNS services?

Note: although this is a Java app, this question is really about DNS at
its core.
I'm designing a Java web app and would like ability to deploy it to 2 sets
of app servers: a LIVE environment, hosted at IP Address #1 (IP1), and a
DR (disaster recovery) environment hosted at IP Address #2 (IP2).
I'll have an external monitor constantly requesting healthy checks from
the LIVE environment (specifically, HTTP requests to a
HealthCheckServlet). If the health check comes back bad, or experiences a
bad (4XX- or 5XX-range) response, I want to automatically failover to my
DR environment. This would require changing the DNS settings so that they
now "map" my domain name to IP2 instead of IP1.
Are there any DNS-as-a-service providers out there that expost SOAP/REST
APIs that allow me to do this failover programmatically? OpenDNS and
DynamicDNS both seem to have APIs, but from what I can tell, their only
for basic account management. Thanks in advance!