Saga pattern for distributed transactions in Microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a saga step that triggers a local transaction.

Microservices

def saga_step():
    # Start local transaction
    [1]()
    # Proceed to next step

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

Abegin_transaction

Bcommit_transaction

Crollback_transaction

Dsend_compensate

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit_transaction instead of begin_transaction.

The saga step must begin a local transaction before processing.

2fill in blank

medium

Complete the code to send a compensation event when a saga step fails.

Microservices

def handle_failure():
    # Send compensation event
    [1]('compensate')

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

Astart_transaction

Brollback_transaction

Ccommit_transaction

Dsend_event

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit_transaction instead of sending an event.

Compensation is done by sending a compensation event to undo previous steps.

3fill in blank

hard

Fix the error in the saga coordinator code to correctly handle step completion.

Microservices

def saga_coordinator(event):
    if event.type == 'step_completed':
        [1]()  # Proceed to next saga step

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

Astart_saga

Btrigger_next_step

Csend_compensation

Drollback_saga

Attempts:

3 left

💡 Hint

Common Mistakes

Calling send_compensation instead of triggering next step.

When a step completes, the coordinator triggers the next step in the saga.

4fill in blank

hard

Fill both blanks to define a saga step that executes a local transaction and sends a success event.

Microservices

def execute_step():
    [1]()  # Commit transaction
    [2]('step_completed')  # Notify coordinator

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

Acommit_transaction

Bsend_event

Cbegin_transaction

Drollback_transaction

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the order or using rollback instead of commit.

The step commits its transaction and then sends a completion event.

5fill in blank

hard

Fill all three blanks to implement a saga step that begins a transaction, handles failure by sending compensation, and commits on success.

Microservices

def saga_step_handler():
    [1]()  # Begin transaction
    try:
        process_local_transaction()
        [2]()  # Commit transaction
    except Exception:
        [3]('compensate')  # Send compensation event

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

Abegin_transaction

Bcommit_transaction

Csend_event

Drollback_transaction

Attempts:

3 left

💡 Hint

Common Mistakes

Using rollback_transaction instead of sending compensation event.

The step begins a transaction, commits if successful, and sends a compensation event if it fails.