Counter pattern in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to increment a counter named 'page_views' by 1.

Redis

INCR [1]

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

Acounter

Bviews_count

Cpage_views

Dvisits

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different key name that does not exist.

Forgetting to use the INCR command.

The INCR command increases the value of the given key by 1. Here, the counter key is 'page_views'.

2fill in blank

medium

Complete the code to get the current value of the counter 'user_logins'.

Redis

GET [1]

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

Alogins

Buser_logins

Clogin_count

Dcount_users

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong key name that does not hold the counter.

Using a command other than GET to retrieve the value.

The GET command retrieves the current value stored at the key. Here, the key is 'user_logins'.

3fill in blank

hard

Fix the error in the code to decrement the counter 'active_sessions' by 1.

Redis

DECR [1]

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

Aactive_sessions

Bsessions_active

CactiveSession

Dsession_count

Attempts:

3 left

💡 Hint

Common Mistakes

Using a key name with different spelling or casing.

Using INCR instead of DECR for decrementing.

The DECR command decreases the value of the given key by 1. The key must be exactly 'active_sessions'.

4fill in blank

hard

Fill both blanks to set the counter 'error_count' to 0 and then increment it by 1.

Redis

SET [1] 0
INCR [2]

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

Aerror_count

BerrorCount

Cerrors

Dcount_errors

Attempts:

3 left

💡 Hint

Common Mistakes

Using different key names in SET and INCR commands.

Misspelling the key name.

Both commands must use the exact key name 'error_count' to reset and then increment the counter.

5fill in blank

hard

Fill all three blanks to atomically increment 'page_hits' by 1, set an expiration of 60 seconds, and then get its value.

Redis

MULTI
INCR [1]
EXPIRE [2] [3]
EXEC

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

Apage_hits

BpageHits

C60

D120

Attempts:

3 left

💡 Hint

Common Mistakes

Using different key names in the transaction.

Setting wrong expiration time.

Forgetting to use MULTI/EXEC for atomicity.

All commands must use the exact key 'page_hits'. The expiration time is set to 60 seconds.