TTL configuration in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a TTL of 60 seconds in the cache manager options.

NestJS

CacheModule.register({ ttl: [1] })

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

A-1

B60

C0

D6000

Attempts:

3 left

💡 Hint

Common Mistakes

Using milliseconds instead of seconds.

Setting TTL to 0 which disables expiration.

The ttl option sets the time-to-live in seconds. Here, 60 means cache entries expire after 60 seconds.

2fill in blank

medium

Complete the code to inject the cache manager service in a NestJS service constructor.

NestJS

constructor(@Inject(CACHE_MANAGER) private [1]: Cache) {}

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

AcacheClient

BcacheService

Ccache

DcacheManager

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name that does not match the injected token.

Forgetting to mark the variable as private.

The injected variable name is commonly cacheManager to represent the cache service instance.

3fill in blank

hard

Fix the error in setting a TTL for a specific cache key using the cache manager's set method.

NestJS

await this.cacheManager.set('user_123', userData, [1]);

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

A{ ttl: 60 }

B60000

C60

D{ ttl: 60000 }

Attempts:

3 left

💡 Hint

Common Mistakes

Passing TTL as a raw number instead of an options object.

Confusing seconds and milliseconds units.

The set method expects the TTL option as an object with a ttl property in seconds. Here, { ttl: 60 } sets TTL to 60 seconds.

4fill in blank

hard

Fill both blanks to configure the cache module with a TTL of 120 seconds and a max cache size of 100 items.

NestJS

CacheModule.register({ ttl: [1], max: [2] })

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

A120

B60

C100

D200

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up TTL and max values.

Using TTL in milliseconds instead of seconds.

The ttl is set to 120 seconds for cache expiration, and max limits the cache size to 100 items.

5fill in blank

hard

Fill all three blanks to create a cache key with a prefix, set a TTL of 30 seconds, and store the value using the cache manager.

NestJS

const key = `session:[1]`;
await this.cacheManager.set(key, [2], { ttl: [3] });

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

AuserId

BsessionData

C30

DuserToken

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong variable for the key or value.

Setting TTL as a string instead of a number.

The key uses a prefix session: plus the userId. The value stored is sessionData with a TTL of 30 seconds.