Topics3
Subscribers3
Messages Sent0
Publisher
idle
→
Broker
3 topics
→
Subscribers
3 total
topic: orders(2 subscribers)
sub-1
no messages
sub-2
no messages
topic: payments(1 subscribers)
sub-3
no messages
topic: notifications(0 subscribers)

// event log

No events yet.

// how it works

  • Publishers send to a named topic
  • Broker fans out to all topic subscribers
  • Subscribers are decoupled from publishers
  • New subscribers get future messages only

// trade-offs

  • Loose coupling — publishers don't know consumers
  • Easy to add new subscribers dynamically
  • No replay — missed messages are gone
  • Ordering not guaranteed across subscribers