Consistency models (strong, eventual) in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a consistency model where all reads see the latest write.

HLD

consistency_model = "[1]"  # Ensures all reads see the latest write

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

Acausal

Beventual

Cstrong

Dweak

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing eventual consistency which allows delays in visibility.

Strong consistency means every read returns the most recent write.

2fill in blank

medium

Complete the code to define a consistency model where updates propagate over time.

HLD

consistency_model = "[1]"  # Updates may not be immediately visible

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

Astrong

Bsequential

Clinearizable

Deventual

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing with strong consistency which requires immediate visibility.

Eventual consistency means updates will be visible after some time delay.

3fill in blank

hard

Fix the error in the code to correctly represent a strong consistency check.

HLD

if read_value == [1]:  # Check if read matches latest write

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

Aold_value

Blatest_write

Cany_value

Dstale_value

Attempts:

3 left

💡 Hint

Common Mistakes

Using old or stale values instead of the latest write.

Strong consistency requires the read to match the latest write.

4fill in blank

hard

Fill both blanks to complete the description of eventual consistency behavior.

HLD

while not [1]:  # Wait until [2] is visible to all nodes
    sleep(1)

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

Aall_nodes_updated

Blatest_update

Cany_node_updated

Dstale_data

Attempts:

3 left

💡 Hint

Common Mistakes

Waiting for only any node to update instead of all nodes.

Eventual consistency waits until all nodes are updated with the latest update.

5fill in blank

hard

Fill all three blanks to complete the code snippet illustrating consistency model selection.

HLD

def select_consistency_model(require_strong):
    if require_strong:
        return "[1]"
    else:
        return "[2]"  # [3] consistency allows delays

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

Astrong

Beventual

CEventual

DStrong

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing case sensitivity or confusing the models.

The function returns strong consistency if required, otherwise eventual consistency which allows delays.