microservice-marigold-hotels

Glossary

Korean	English	Description
호텔	property	a hotel
객실	room	a physical room
객실 유형	room type	a type of room, e.g. "Deluxe King"
날짜별 객실 유형 요금	price chart	the pricing of a room type on a given day
요금별 객실 유형 재고	room rate bucket	quantity of rooms offered at a particular rate
객실 요금	room rate	a room rate
예약	reservation	a reservation of a room type for a range of days
일별 예약 요금	reserved rate	one for each day of reservation
체크인	check in	a room is assigned to the guest
체크아웃	check out	the status of the room is available
고객	customer	who can make reservations
투숙객	guest	makes reservations and stays at hotels
호텔 운영자	hotel operator	defines properties and pricing
직원	front desk employee	checks in and out guests

Identify system operations

System operations

Story	Command	Queries
Create room type	createRoomType(name, description)
Create property	createProperty(name, address, rooms)
Create room rate	createRoomRate(propertyId, name, price)	- findProperties()
Set prices	setPrice(propertyId, date, roomType, [(quantity, roomRateId1), …])	- findProperties() - findRoomTypesForProperty(propertyId) - findRoomRatesForProperty(propertyId)
Make reservation	createReservation(property, roomType, stayDateRange, dailyRoomRates, guest)	- findAvailableProperties(address, stayDateRange) - findAvailableRoomsAndRates(propertyId, stayDateRange)
Check in	checkIn(reservationId, roomNumber)	- findReservations(propertyId, searchCriteria) - findAvailableRooms(reservationId)
Check out	checkOut(reservationId)	- findReservations(propertyId, searchCriteria)

Command

createRoomType()

Operation	createRoomType(name, description)
Returns
Preconditions	room type with that name does not exist
Postconditions	a room type was created

createProperty()

Operation	createProperty(name, address, rooms)
Returns
Preconditions	- has valid room types - should be no duplicate room numbers
Postconditions	a property was created

createRoomRate()

Operation	createRoomRate(propertyId, name, price)
Returns
Preconditions	room rate with that name does not exist at the property
Postconditions	a room rate was created

setPrice()

Operation	setPrice(propertyId, date, roomType, [(quantity, roomRateId1), …])
Returns
Preconditions	- valid property - a date in the future - valid room type at the property - valid room rate and quantity pairs
Postconditions	a price chart was created

createReservation()

Operation	createReservation(property, roomType, stayDateRange, dailyRoomRates, guest)
Returns
Preconditions	- valid credit card - a stay date range that is not in the past - valid property - valid room type at the property - room rate bucket should remain for the stay date range
Postconditions	- a reservation was created - a room rate bucket has been reduced

checkIn()

Operation	checkIn(reservationId, roomNumber)
Returns
Preconditions	- valid reservation - valid credit card - the room is available
Postconditions	- the room is assigned to the guest - the state of the guest is checked in

checkOut()

Operation	checkOut(reservationId)
Returns
Preconditions	valid credit card
Postconditions	- the state of the room is available - the state of the guest is checked out - the guest's credit card is charged

Queries

Query	Description
findProperties(searchCriteria)	Returns the list of properties
findRoomTypesForProperty(propertyId)	Returns the list of room types for the specified properties
findAvailableProperties(address, stayDateRange)	Returns the list of properties near the address that have availability for the specified stay date range
findAvailableRoomsAndRates(propertyId, stayDateRange)	Returns the available room rates for the specified property and stay date range
findReservations(propertyId, searchCriteria)	find the reservations for a property that match the search criteria

Define subdomains

Property Management

Name	Property Management
Responsibilities	manages information about properties
Collaborations	external address validation and geocoding service
Type	Supporting
Complexity	Simple
Key aggregates	Property

Reservation Management

Name	Reservation Management
Responsibilities	manages information about reservations
Collaborations
Type	Core
Complexity	Complicated
Key aggregates	Reservation

Check In and Out Management

Name	Check In and Out Management
Responsibilities	- executes check in and out - manages available rooms
Collaborations
Type	Supporting
Complexity	Simple
Key aggregates	Room

Payment Management

Name	Payment Management
Responsibilities	makes payment
Collaborations
Type	Generic
Complexity	Simple
Key aggregates	CreditCard

Group subdomains into services

Properties Management Service

• Property Management

Reservation Management Service

• Reservation Management
• Check In and Out Management

Payment Management Service

• Payment Management

Design system operations

Command	Service	Implementation
createRoomType()	Properties Management Service	Local
createProperty()	Properties Management Service	Local
createRoomRate()	Reservation Management Service	Local
setPrice()	Reservation Management Service	Local
createReservation()	Reservation Management Service	Local
checkIn()	Reservation Management Service	Local
checkOut()	Reservation Management Service	Saga

Design system queries

Query	Implementation
findProperties()	Properties Management Service
findRoomTypesForProperty()	Properties Management Service
findAvailableProperties()	API Composition
findAvailableRoomsAndRates()	Reservation Management Service
findReservations()	Reservation Management Service

Saga design

createProperty()

sequenceDiagram
    autonumber
    actor operator as hotel operator
    participant property as Properties Management Service
    participant reservation as Reservation Management Service
    operator->>property: createProperty()
    property->>property: check has valid room types
    property->>property: should be no duplicate room numbers
    property->>property: craete property
    property->>reservation: publish RoomCreatedEvent
    property->>property: create room

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createReservation()

sequenceDiagram
    autonumber
    actor customer
    participant reservation as Reservation Management Service
    participant payment as Payment Management Service
    participant property as Properties Management Service
    customer->>reservation: createReservation()
    reservation->>payment: check valid credit card
    reservation->>reservation: check a stay date range that is not in the past
    reservation->>property: check valid property
    reservation->>property: check valid room type at the property
    reservation->>reservation: check room rate bucket should remain for the stay date range
    reservation->>reservation: create a reservation
    reservation->>reservation: reduce a a room rate bucket

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checkIn()

sequenceDiagram
    autonumber
    actor employee as front desk employee
    participant reservation as Reservation Management Service
    participant payment as Payment Management Service
    employee->>reservation: checkIn()
    reservation->>reservation: check valid reservation
    reservation->>reservation: check the room is available
    reservation->>payment: check valid credit card
    reservation->>reservation: assign the room to the guest
    reservation->>reservation: change the state of the guest as checked in

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checkOut()

flowchart
    subgraph reservation ["Reservation Management Service"]
    checkOut["1. checkOut()"]
    roomToAvailable["3. changeToAvailableRoom()"]
    guestCheckOut["4. checkOutGuest()"]
    end
    subgraph broker ["Message broker"]
    reservationEvents(["Reservation events"])
    paymentEvents(["Payment events"])
    end
    subgraph payment ["Payment Service"]
    chargeCreditCard["2. chargeCreditCard()"]
    end
    reservation--Checked out-->reservationEvents
    reservationEvents-.->payment
    payment-->paymentEvents
    paymentEvents-.->reservation

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sequenceDiagram
    autonumber
    actor employee as front desk employee
    participant reservation as Reservation Management Service
    participant payment as Payment Management Service
    participant SAGA
    employee->>reservation: checkOut()
    reservation->>reservation: check a checked-in guest
    reservation->>payment: check valid credit card
    reservation->>SAGA: request charge the guest's creadit card
    SAGA-->>payment: notify Saga Created
    payment->>payment: charge the guest's credit card
    payment->>SAGA: guest's credit card is charged
    SAGA->>reservation: notify Saga Finished
    reservation->>reservation: finish payment
    reservation-->>employee: thx
    reservation->>reservation: change the state of the room as available
    reservation->>reservation: change the state of the guest as check out

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