Why caching patterns matter in Redis - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a key-value pair in Redis.

Redis

redis_client.[1]('user:1', 'Alice')

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

Aset

Bget

Cdelete

Dexpire

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' instead of 'set' to store data.

Using 'expire' which sets a timeout, not the value.

The set command stores a value for a key in Redis.

2fill in blank

medium

Complete the code to retrieve a value by key from Redis.

Redis

value = redis_client.[1]('user:1')

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

Adel

Bset

Cexpire

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'set' which writes data instead of reading.

Using 'del' which deletes keys.

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

3fill in blank

hard

Fix the error in the code to set a key with expiration time.

Redis

redis_client.set('session:123', 'active', [1]=3600)

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

Atimeout

Bex

Cexpire

Dttl

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'expire' as a parameter in set instead of 'ex'.

Using 'ttl' which is a command to check time left.

The ex parameter sets the expiration time in seconds when using set.

4fill in blank

hard

Fill both blanks to implement a cache check and set pattern.

Redis

value = redis_client.[1]('item:42')
if value is None:
    value = fetch_from_db('item:42')
    redis_client.[2]('item:42', value, ex=300)

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

Aget

Bset

Cdelete

Dexpire

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'set' to read or 'get' to write.

Using 'expire' instead of 'set' to write data.

First, get tries to read from cache. If missing, fetch from DB and set caches it with expiration.

5fill in blank

hard

Fill all three blanks to implement a cache invalidation after update.

Redis

redis_client.[1]('product:99')
update_database('product:99', new_data)
redis_client.[2]('product:99', new_data)
redis_client.[3]('product:99', 600)

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

Adelete

Bset

Cexpire

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Not deleting old cache before updating.

Using 'get' instead of 'delete' to remove cache.

First, delete old cache with delete. Then update DB and cache with set. Finally, set expiration with expire.