Unsubscribing in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does unsubscribing mean in GraphQL subscriptions?

Unsubscribing means stopping the live updates from a GraphQL subscription. It tells the server you no longer want to receive data changes.

beginner

How do you unsubscribe from a GraphQL subscription in client code?

You call the unsubscribe() method on the subscription object returned when you start the subscription.

intermediate

Why is unsubscribing important in GraphQL subscriptions?

Unsubscribing frees up resources on both client and server. It stops unnecessary data flow and saves bandwidth and memory.

intermediate

What happens if you don't unsubscribe from a GraphQL subscription?

The subscription stays active, and the client keeps receiving updates. This can cause wasted resources and slow performance.

beginner

Show a simple example of unsubscribing from a GraphQL subscription using JavaScript.

const subscription = client.subscribe({ query: MY_SUBSCRIPTION }).subscribe({
  next(data) { console.log(data); },
  error(err) { console.error(err); }
});

// Later when you want to stop:
subscription.unsubscribe();

What method do you call to stop receiving updates from a GraphQL subscription?

A stop()

B unsubscribe()

C cancel()

D end()

The correct method to stop a subscription is unsubscribe().

Why should you unsubscribe from a GraphQL subscription when no longer needed?

A To increase data flow

B To restart the subscription automatically

C To save server and client resources

D To change the subscription query

Unsubscribing saves resources by stopping unnecessary data updates.

If you forget to unsubscribe, what is a likely consequence?

A You keep receiving updates and waste resources

B The subscription stops automatically

C The server disconnects the client

D The client crashes immediately

Without unsubscribing, updates continue and resources are wasted.

In JavaScript, what does the subscribe() method return?

A A promise

B A boolean value

C A string token

D An object with an unsubscribe() method

subscribe() returns an object that has an unsubscribe() method to stop updates.

Which of these is NOT a reason to unsubscribe?

A To keep receiving data

B To reduce network traffic

C To prevent memory leaks

D To improve app performance

Unsubscribing stops data flow, so keeping data means not unsubscribing.

Explain what unsubscribing means in GraphQL subscriptions and why it is important.

Think about stopping live updates and saving resources.

Describe how you unsubscribe from a GraphQL subscription in client code with an example.

Focus on the object returned by subscribe() and its method.