Why events decouple services in Microservices - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to show how an event helps services communicate without direct calls.

Microservices

serviceA.publish([1])

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

A"OrderCreatedEvent"

B"SynchronousRequest"

C"DirectCall"

D"TightlyCoupledCall"

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing direct or synchronous calls which tightly couple services.

Publishing an event like "OrderCreatedEvent" allows services to communicate without direct calls, enabling decoupling.

2fill in blank

medium

Complete the code to show how a service listens for an event to react asynchronously.

Microservices

eventBus.subscribe("OrderCreatedEvent", [1])

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

AhandleOrderCreated

BcallServiceDirectly

CsendSyncRequest

DblockUntilResponse

Attempts:

3 left

💡 Hint

Common Mistakes

Using direct calls or blocking functions which reduce decoupling.

Subscribing with a handler function like handleOrderCreated allows reacting to events asynchronously.

3fill in blank

hard

Fix the error in the code to properly decouple services using events.

Microservices

serviceB.processOrder()  # Incorrect direct call
serviceA.[1](orderData)  # Correct event publish

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

AcallDirectly

BinvokeService

CpublishEvent

DsendSyncRequest

Attempts:

3 left

💡 Hint

Common Mistakes

Keeping direct calls which tightly couple services.

Using publishEvent sends an event instead of a direct call, decoupling services.

4fill in blank

hard

Fill both blanks to complete the event-driven communication pattern.

Microservices

eventBus.[1]("PaymentProcessed", [2])

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Apublish

BhandlePayment

Csubscribe

DsendRequest

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up publish and subscribe methods.

Subscribing to the "PaymentProcessed" event with handlePayment decouples services.

5fill in blank

hard

Fill all three blanks to complete the event-driven service interaction.

Microservices

serviceA.[1]("UserRegistered", data)

serviceB.[2]("UserRegistered", [3])

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

Aemit

Bsubscribe

ChandleUserRegistration

DcallDirectly

Attempts:

3 left

💡 Hint

Common Mistakes

Using direct calls instead of events.

Service A emits the "UserRegistered" event, and Service B subscribes to it with handleUserRegistration to stay decoupled.