Built in Status Datastreams

Status Datastream

A system/procedure can enable the built-in status datastream to report internal status of all other data streams that it generates.

The record is sent regularly (or irregularly depending on next heart beat) as a heart-beat and is structured as so:

• timestamp
• output name
• status code (ENABLED, DISABLED, INTERRUPTED, ENDED)
• next expected heart-beat timestamp
• custom message string

MQTT Data Source

An MQTT source can rely on the protocol keep-alive timeout and PINGREQ to detect a half-open connection.

The status code should be set to:

• INTERRUPTED when a PING hasn't been received before the keep-alive timeout
• ENABLED when the client connects
• DISABLED when the client disconnects cleanly
• (ENDED when the topic is closed but that cannot be done via MQTT)

Websocket Data Source

Websocket also has a PING/PONG mechanism that can be used as a heartbeat.

• INTERRUPTED when a message or PING hasn't been received before the timeout
• ENABLED when the client connects
• DISABLED when the client disconnects cleanly
• (ENDED when the topic is closed but that cannot be done via WS)

REST API POST requests like STA or SWAPI

• ENABLED when the first POST is received
• DISABLED when no POST requests received before timeout (how to set timeout?)
• ENDED