7. Shopping Cart Item Item C
Shopping Cart
User
Item B
Item A
Item D
State
Shopping Cart Item Added
Item: C
…
…
…
Events
8. Item C
Shopping Cart
User
Item B
Item A
Item D
Shopping Cart Item Added
Item: C
…
…
…
Events State
Shopping Cart Item Removed
Item: C
Shopping Cart Item
24. There are only two hard problems in
distributed systems: 2. Exactly-once delivery
1. Guaranteed order of messages 2. Exactly-
once delivery
- Mathias Verraes