joharikushagra / notification-cosmofeed

Notification-service Design Implementation

Getting Started

• Install Dependencies

npm install

• Setup .env with following variables

MONGO_PASSWORD=YOUR_MONGO_PASSWORD
MONGO_USERNAME=YOUR_MONGO_USERNAME

• Start the server

npm start

About Design

This notification service follows the below architecture which have the following components

1. Client: These can be devices or external APIs trying to generate notifcation.
2. Server: Accept the incoming requests and send it to the notification APIs.
3. Notification Service:

• Core of the design responsible, to accept the incoming payload and generate notifications.
• Responsible for creating notification channels as mentioned in request and performs the trigger.
• It is assisted by Channels Factory which creates instances of different channels/mediums of nofitication. This follows factory design pattern to keep separation of different concerns.
• Saves the notification log into the database.
• APIs can interact with database and return the response.

Digram showing the interaction of various components

• The above design is a scalable version of former implementation.
• This follows inclusion of notification queue (RabbitMq, Kafka) which would get all the notifications requests from the service.
• Multiple workers can be spawned to consume the entries from the queue and can perform operations and store them into the database distributing the load at scale.

Routes

GET:

/notifications - getAllNotifications

/notifications/:id - getNotificationById

POST:

/notifications - createNotification

Sample body for creating request
{
    recipient: '[e-mail]',
    message: 'Get 30% off on all men's wear',
    channel: 'email'
}

Note: Channels are ['sms','email','push']

PUT

/notifications/:id - updateNotificationStatusById

DELETE

/notifications/:id - deleteNotificationById