Data consistency challenges in Microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to choose the consistency model that ensures all nodes see the same data at the same time.

Microservices

consistency_model = "[1]"

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

AStrong Consistency

BEventual Consistency

CCausal Consistency

DRead Your Writes

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing Eventual Consistency which allows delays in data synchronization.

Strong consistency means all nodes see the same data immediately after a write.

2fill in blank

medium

Complete the code to select the pattern that helps maintain data consistency across microservices asynchronously.

Microservices

consistency_pattern = "[1]"

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

ACircuit Breaker

BEvent Sourcing

CTwo-Phase Commit

DSaga Pattern

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing with Two-Phase Commit which is synchronous and blocking.

The Saga Pattern manages distributed transactions by breaking them into smaller steps with compensations.

3fill in blank

hard

Fix the error in the statement about consistency guarantees in microservices.

Microservices

The [1] model allows temporary inconsistencies but guarantees eventual data synchronization.

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

AEventual Consistency

BLinearizability

CStrong Consistency

DSerializability

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing Strong Consistency which does not allow temporary inconsistencies.

Eventual Consistency allows temporary differences but ensures data will become consistent eventually.

4fill in blank

hard

Fill both blanks to complete the code snippet that defines a distributed transaction using the Saga pattern.

Microservices

def saga_transaction():
    try:
        [1]()
        [2]()
    except Exception:
        compensate()

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

Astep_one

Bstep_two

Ccommit

Drollback

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit or rollback which are not individual saga steps.

In Saga, each step is a local transaction like step_one and step_two, with compensation on failure.

5fill in blank

hard

Fill all three blanks to complete the code that implements a simple eventual consistency check.

Microservices

def check_consistency(data_store):
    for node in data_store:
        if node.[1] != data_store.master.[2]:
            node.[3](data_store.master.data)

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

Aget_data

Bdata

Csync

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using sync instead of update which is not a method here.

The function compares data from each node with the master and updates nodes that differ.