Cache-aside pattern in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the key exists in Redis cache.

Redis

if redis_client.[1](key):

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

Aexists

Bget

Cset

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' instead of 'exists' returns the value, not presence.

Using 'set' or 'delete' changes data instead of checking.

The exists command checks if a key is present in Redis.

2fill in blank

medium

Complete the code to retrieve a value from Redis cache.

Redis

value = redis_client.[1](key)

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

Aget

Bset

Cexists

Dexpire

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'exists' returns a boolean, not the value.

Using 'set' writes data, not reads it.

The get command fetches the value stored at the given key.

3fill in blank

hard

Fix the error in the code to store data in Redis cache.

Redis

redis_client.[1](key, value)

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

Adelete

Bexists

Cget

Dset

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' tries to read instead of write.

Using 'exists' checks presence, not store.

The set command stores a value at the given key in Redis.

4fill in blank

hard

Fill both blanks to implement cache-aside pattern: check cache and fetch from DB if missing.

Redis

if redis_client.[1](key):
    value = redis_client.[2](key)
else:
    value = fetch_from_db(key)

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

Aexists

Bget

Cset

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' to check presence causes errors if key missing.

Using 'set' or 'delete' in place of 'get' is incorrect.

First, exists checks if key is in cache. Then, get retrieves the value.

5fill in blank

hard

Fill all three blanks to complete cache-aside: fetch from DB, store in cache, then return value.

Redis

if not redis_client.[1](key):
    value = fetch_from_db(key)
    redis_client.[2](key, value)
else:
    value = redis_client.[3](key)

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

Aexists

Bset

Cget

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' to check presence causes errors.

Forgetting to store fetched data in cache.

Check if key exists. If not, fetch from DB and set in cache. Otherwise, get from cache.