Oracle availability monitoring

[hal0x2328]

Summary or problem description
The Oracle nodes on TestNet seem to be unreliable for the past week, with only a single node being able to connect to any remote API server while the other nodes time out (or have other connectivity/DNS/SSL issues).

Do you have any solution you want to propose?
Implement an interval-based heartbeat request in the Oracle plugin, that checks into one or more remote API servers that can send an alert to multiple parties if an Oracle node fails to check in after a period of time. The heartbeat request could also contain statistics on recent requests or other diagnostic information.

Where in the software does this update applies to?

• Plugins