This CorDapp is a simple showcase of scheduled activities (i.e. activities started by a node at a specific time without direct input from the node owner).

A node starts its heartbeat by calling the StartHeartbeatFlow. This creates a HeartState on the ledger. This HeartState has a scheduled activity to start the HeatbeatFlow one second later.

When the HeartbeatFlow runs one second later, it consumes the existing HeartState and creates a new HeartState. The new HeartState also has a scheduled activity to start the HeatbeatFlow in one second.

In this way, calling the StartHeartbeatFlow creates an endless chain of HeartbeatFlows one second apart.

See https://docs.corda.net/getting-set-up.html.

See https://docs.corda.net/tutorial-cordapp.html#running-the-example-cordapp.

Java use the contracts-java:deployNodes task and ./contracts-java/build/nodes/runnodes script.

Kotlin use the contracts-kotlin:deployNodes task and ./contracts-kotlin/build/nodes/runnodes script.

Go to the CRaSH shell for PartyA, and run the StartHeatbeatFlow:

start StartHeartbeatFlow

If you now start monitoring the node's flow activity...

flow watch

...you will see the Heartbeat flow running every second until you close the Flow Watch window using ctrl/cmd + c:

xxxxxxxx-xxxx-xxxx-xx Heartbeat xxxxxxxxxxxxxxxxxxxx Lub-dub