Saga 旅行预订架构

Architecture

旅行预订 Saga 架构图，将航班、酒店和租车预订编排为单一分布式事务，任何预订步骤失败时自动补偿取消所有预订。该模板模拟经典的 Saga 用例，多个独立服务必须全部成功或全部回滚，确保旅客不会出现部分预订。非常适合用真实业务场景演示 Saga 模式。

下载 .fz 文件

完整 FlowZap 代码

BookingAPI { # Booking API
n1: circle label:"Book Travel Package"
n2: rectangle label:"Validate Booking Request"
n3: rectangle label:"Start Booking Saga"
n4: rectangle label:"Return Booking Status"
n5: circle label:"End"
n1.handle(right) -> n2.handle(left)
n2.handle(right) -> n3.handle(left) [label="Valid"]
n3.handle(bottom) -> Saga.n6.handle(top) [label="Execute"]
n4.handle(right) -> n5.handle(left)
}
Saga { # Saga Orchestrator
n6: rectangle label:"Step 1: Book Flight"
n7: rectangle label:"Step 2: Book Hotel"
n8: rectangle label:"Step 3: Book Car Rental"
n9: diamond label:"All Bookings OK?"
n10: rectangle label:"Confirm All Reservations"
n11: rectangle label:"Compensate Failed Steps"
n6.handle(right) -> n7.handle(left) [label="Flight OK"]
n7.handle(right) -> n8.handle(left) [label="Hotel OK"]
n8.handle(right) -> n9.handle(left)
n9.handle(right) -> n10.handle(left) [label="All Success"]
n9.handle(bottom) -> n11.handle(top) [label="Any Failed"]
n10.handle(top) -> BookingAPI.n4.handle(bottom) [label="Confirmed"]
n11.handle(top) -> BookingAPI.n4.handle(bottom) [label="Cancelled"]
n6.handle(bottom) -> FlightService.n12.handle(top) [label="Reserve"]
n7.handle(bottom) -> HotelService.n14.handle(top) [label="Reserve"]
n8.handle(bottom) -> CarService.n16.handle(top) [label="Reserve"]
}
FlightService { # Flight Service
n12: rectangle label:"Reserve Flight Seat"
n13: rectangle label:"Cancel Flight (Compensate)"
n12.handle(top) -> Saga.n7.handle(bottom) [label="Reservation ID"]
n13.handle(top) -> Saga.n11.handle(bottom) [label="Cancelled"]
}
HotelService { # Hotel Service
n14: rectangle label:"Reserve Hotel Room"
n15: rectangle label:"Cancel Hotel (Compensate)"
n14.handle(top) -> Saga.n8.handle(bottom) [label="Reservation ID"]
n15.handle(top) -> Saga.n11.handle(bottom) [label="Cancelled"]
}
CarService { # Car Rental Service
n16: rectangle label:"Reserve Car"
n17: rectangle label:"Cancel Car (Compensate)"
n16.handle(top) -> Saga.n9.handle(bottom) [label="Reservation ID"]
n17.handle(top) -> Saga.n11.handle(bottom) [label="Cancelled"]
}

为什么需要这个工作流？

Travel bookings involve multiple independent services (flights, hotels, car rentals) that must either all succeed or all be cancelled—a partial booking is worse than no booking. The saga pattern ensures atomicity across these services without distributed transactions, with automatic compensation for failed steps.

工作原理

Step 1: The booking API validates the travel package request and starts the saga.
Step 2: Step 1: The Flight Service reserves a seat on the requested flight.
Step 3: Step 2: The Hotel Service reserves a room for the travel dates.
Step 4: Step 3: The Car Rental Service reserves a vehicle at the destination.
Step 5: If all reservations succeed, all are confirmed simultaneously.
Step 6: If any reservation fails, compensation actions cancel all previously made reservations.

替代方案

Manual booking with separate confirmations risks partial bookings. Travel aggregators handle this internally but charge commissions. This template demonstrates the saga pattern with the classic travel booking use case.

Key Facts

Template Name	Saga 旅行预订架构
Category	Architecture
Steps	6 workflow steps
Format	FlowZap Code (.fz file)