Helper data and functions should be in a microservice?

Question

I am creating an application using microservice architecture. I have broken down the domains into one microservice. I have two questions regarding handling additional data and functions.

1. I have created an MS named ms-notification to handle all the users' notifications such as SMS, Email, Push notifications,...
   When I need to send a notification to a user, I publish an event and consume that in ms-notification. Is it a good approach to do this?
   

2. I have a list of Courses that contains about 2000 Courses(Id, name, ...) and CourseId is being used approximately across all the microservices. Should I store these 2000 Courses in each microservice's database? (I am using a single database per microservice) Or should I create a new microservice and expose the 2000 list with an API controller?
   

Thank you in advance!

Answer 1

1. Yes, it is a good approach to have it Event-Driven, however you can also have separate microservices for each type of notification, because they are independent, i.e.,
   1. SMS Microservice
   2. Email Microservice
   3. Push Notifications Microservice

                 ┌─────────────┐
                 │    Other    │
                 │Microservices│
                 └──────┬──────┘
                        │
                        │
                     Publish
                       SMS
                      Email
                  Notif Events
                        │
                        ▼
                 ┌──────────────┐
                 │ Event Queue  │
                 └──────────────┘
                        ▲
                        │
                        │ Subscribe
                        │
       ┌────────────────┼────────────────┐
       │                │                │
       │                │                │
┌──────┴──────┐ ┌───────┴───────┐ ┌──────┴───────┐
│     SMS     │ │  Push Notif.  │ │    Email     │
│ Microservice│ │ Microservice  │ │ Microservice │
└─────────────┘ └───────────────┘ └──────────────┘

This will result in a cleaner architecture.

2. You should create a new microservice. Each microservice should be the owner of its database, i.e., if you want to consume data from another microservice you must do so by invoking a public API.