Heartbeat CorDapp
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.
Pre-requisites:
See https://docs.corda.net/getting-set-up.html.
Usage
Running the nodes:
The nodes do not expose a front-end or API, so you need to deploy from from the command line and interact with them via the CRaSH shell. See https://docs.corda.net/tutorial-cordapp.html#running-the-example-cordapp.
Interacting with the nodes:
Go to the CRaSH shell for PartyA, and run the StartHeatbeatFlow:
flow 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 shut down the node: // HOW TO SHUT DOWN THE NODE? Actually though you press ctrl + c to stop the flow watch window. Then ctrl + c, again to shutdown the node.
xxxxxxxx-xxxx-xxxx-xx Heartbeat xxxxxxxxxxxxxxxxxxxx Lub-dub