Event Driven Workflow

patterns

This workflow models reacting to incoming business events.

Full FlowZap Code

Producer { # Event Producer
n1: circle label:"Start"
n2: rectangle label:"User action occurs"
n3: rectangle label:"Create event payload"
n4: rectangle label:"Publish to message broker"
n5: circle label:"End"
n1.handle(right) -> n2.handle(left)
n2.handle(right) -> n3.handle(left)
n3.handle(bottom) -> MessageBroker.n6.handle(top) [label="Publish"]
n4.handle(right) -> n5.handle(left)
}
MessageBroker { # Message Broker
n6: rectangle label:"Receive event message"
n7: rectangle label:"Validate message schema"
n8: diamond label:"Valid schema?"
n9: rectangle label:"Route to topic partition"
n10: rectangle label:"Send to dead letter queue"
n11: rectangle label:"Acknowledge receipt"
n6.handle(right) -> n7.handle(left)
n7.handle(right) -> n8.handle(left)
n8.handle(right) -> n9.handle(left) [label="Yes"]
n8.handle(bottom) -> n10.handle(top) [label="No"]
n9.handle(right) -> n11.handle(left)
n10.handle(top) -> Producer.n5.handle(bottom) [label="DLQ"]
n11.handle(top) -> Producer.n4.handle(bottom) [label="ACK"]
n11.handle(bottom) -> Consumer.n12.handle(top) [label="Deliver"]
}
Consumer { # Event Consumer
n12: rectangle label:"Poll for new messages"
n13: rectangle label:"Deserialize event"
n14: diamond label:"Event type?"
n15: rectangle label:"Handle order created"
n16: rectangle label:"Handle payment received"
n17: rectangle label:"Handle user registered"
n18: rectangle label:"Process business logic"
n19: rectangle label:"Commit offset"
n12.handle(right) -> n13.handle(left)
n13.handle(right) -> n14.handle(left)
n14.handle(right) -> n15.handle(left) [label="order.created"]
n14.handle(bottom) -> n16.handle(top) [label="payment.received"]
n14.handle(left) -> n17.handle(top) [label="user.registered"]
n15.handle(bottom) -> n18.handle(top)
n16.handle(bottom) -> n18.handle(top)
n17.handle(bottom) -> n18.handle(top)
n18.handle(right) -> n19.handle(left)
n19.handle(top) -> Producer.n5.handle(bottom) [label="Complete"]
}