orchestration: conductor at musical orchestra

choreography: dancers

Orchestration

single point of failure

services depend on orchestrator

lots of communication

order placement needs to be highly available

• orchestrator needs to be highly available

• order placements needs to be highly available

smaller orchestrator (vs Enterprise Service Bus)

eg. Order Placement Orchestrator, Order Cancellation Orchestrator

logic shifts to the orchestrator

error handling becomes a design decision

• in the orchestrator?

• in the service?

-> no new lines, so not architecture, but design

Choreography

highly available, only the starting service

event-driven architecture is typically choreographed

error handling

what if payment says: "oh, but they removed that credit card"

"where is my order?"

-> there is no state owner

either:

• make order placement state owner

• new customer facing service for state ownership

Hybrid

async or sync