vmatresu / heartbeat

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 close the Flow Watch window using ctrl/cmd + c:

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