Event types (domain, integration, notification) in Microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a domain event type.

Microservices

event_type = "[1]"  # Represents an event within the same service boundary

Drag options to blanks, or click blank then click option'

Adomain

Bcommand

Cnotification

Dintegration

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing integration event which is for communication between services.

A domain event represents something that happened inside a single service or bounded context.

2fill in blank

medium

Complete the code to define an integration event type.

Microservices

event_type = "[1]"  # Used to communicate between different microservices

Drag options to blanks, or click blank then click option'

Aintegration

Bnotification

Cdomain

Dcommand

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing with notification events which are for user alerts.

Integration events are used to notify other services about something that happened.

3fill in blank

hard

Fix the error in the event type assignment for a notification event.

Microservices

event_type = "[1]"  # Event type used to inform users or systems about something

Drag options to blanks, or click blank then click option'

Aintegration

Bcommand

Cdomain

Dnotification

Attempts:

3 left

💡 Hint

Common Mistakes

Using domain or integration event types incorrectly here.

Notification events are meant to alert users or external systems about an event.

4fill in blank

hard

Fill both blanks to complete the event type descriptions.

Microservices

domain_event = "[1]"  # Event inside a service
integration_event = "[2]"  # Event between services

Drag options to blanks, or click blank then click option'

Adomain

Bnotification

Cintegration

Dcommand

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up domain and integration event types.

Domain events happen inside a service; integration events happen between services.

5fill in blank

hard

Fill all three blanks to complete the event type assignments.

Microservices

domain_event = "[1]"
integration_event = "[2]"
notification_event = "[3]"

Drag options to blanks, or click blank then click option'

Adomain

Bintegration

Cnotification

Dcommand

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping integration and notification event types.

Each event type corresponds to its role: domain (internal), integration (between services), notification (alerts).

Practice

1. Which type of event in microservices captures important business actions inside a single service?

easy

A. Domain event

B. Integration event

C. Notification event

D. System event

Solution

1. Step 1: Understand event types in microservices

   Domain events represent significant business actions occurring within a single service boundary.

2. Step 2: Differentiate from other event types

   Integration events share data between services, and notification events alert users or external systems, so they are not internal business actions.

3. Final Answer:

   Domain event -> Option A

4. Quick Check:

   Business action inside service = Domain event [OK]

Hint: Domain events are about internal business actions [OK]

Common Mistakes:

• Confusing integration events with domain events
• Thinking notification events capture business logic
• Assuming system event is a standard event type

2. Which of the following is the correct way to describe an integration event in microservices?

easy

A. An event that triggers UI updates within the same service

B. An event that shares information between different services

C. An event that sends alerts to users only

D. An event that logs errors internally

Solution

1. Step 1: Define integration events

   Integration events are designed to share information or changes between different microservices to keep them in sync.

2. Step 2: Eliminate incorrect options

   UI updates are usually local, alerts to users are notification events, and error logs are internal diagnostics, not integration events.

3. Final Answer:

   An event that shares information between different services -> Option B

4. Quick Check:

   Sharing info between services = Integration event [OK]

Hint: Integration events connect multiple services [OK]

Common Mistakes:

• Mixing notification events with integration events
• Thinking integration events only affect one service
• Confusing error logs with integration events

3. Consider this code snippet in a microservice:

publishEvent({ type: 'UserRegistered', payload: { userId: 123 } });

What type of event is this most likely representing?

medium

A. Notification event

B. System event

C. Integration event

D. Domain event

Solution

1. Step 1: Analyze the event name and context

   The event 'UserRegistered' indicates a business action inside the service, such as a user signing up.

2. Step 2: Match event type to definition

   Since it captures a business action inside the service, it is a domain event, not a notification or integration event.

3. Final Answer:

   Domain event -> Option D

4. Quick Check:

   Business action event = Domain event [OK]

Hint: Event names with business actions are domain events [OK]

Common Mistakes:

• Assuming all events are integration events
• Confusing notification events with domain events
• Ignoring event naming conventions

4. A microservice is sending an event to notify users about a password change. The event is mistakenly labeled as an integration event. What is the main issue here?

medium

A. Notification events should not be sent to users

B. Password change is a domain event, not a notification

C. Notification events should not be labeled as integration events

D. Integration events cannot carry user-related data

Solution

1. Step 1: Identify the event purpose

   The event is meant to notify users, which fits the notification event type.

2. Step 2: Understand event labeling importance

   Labeling a notification event as an integration event causes confusion and wrong handling in the system.

3. Final Answer:

   Notification events should not be labeled as integration events -> Option C

4. Quick Check:

   Correct event labeling avoids confusion [OK]

Hint: Match event label to its purpose carefully [OK]

Common Mistakes:

• Mixing notification and integration event roles
• Assuming integration events can't have user data
• Thinking notification events are internal only

5. You are designing a microservices system where a user registration triggers multiple actions: updating internal user stats, notifying other services, and sending a welcome email. Which event types should you use for these actions respectively?

hard

A. Domain event, integration event, notification event

B. Integration event, domain event, notification event

C. Notification event, domain event, integration event

D. Domain event, notification event, integration event

Solution

1. Step 1: Map actions to event types

   Updating internal user stats is a business action inside the service, so it is a domain event.

2. Step 2: Identify cross-service communication

   Notifying other services requires sharing information between services, so it is an integration event.

3. Step 3: Recognize user alerts

   Sending a welcome email is a message to the user, which fits notification events.

4. Final Answer:

   Domain event, integration event, notification event -> Option A

5. Quick Check:

   Internal action, cross-service, user alert = Domain, Integration, Notification [OK]

Hint: Match event type to action scope: internal, cross-service, user [OK]

Common Mistakes:

• Swapping integration and notification events
• Using domain events for cross-service communication
• Confusing notification with domain events