Saga pattern for distributed transactions in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the first step in a saga transaction.

HLD

def saga_step_1():
    # Start transaction
    [1]

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

Abegin_transaction()

Bcommit_transaction()

Crollback_transaction()

Dend_transaction()

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit_transaction() before starting the transaction.

Calling rollback_transaction() as the first step.

The first step in a saga transaction is to begin the transaction to ensure all steps are tracked.

2fill in blank

medium

Complete the code to define the compensation action in a saga step.

HLD

def compensate_step():
    # Undo previous action
    [1]

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Acommit_transaction()

Bexecute_compensation()

Crollback_compensation()

Dstart_compensation()

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit_transaction() instead of compensation.

Calling rollback_compensation() which is not a standard term.

Compensation in saga means executing a specific action to undo the previous step.

3fill in blank

hard

Fix the error in the saga coordinator logic to handle step failure.

HLD

def saga_coordinator():
    try:
        execute_step_1()
        execute_step_2()
    except Exception:
        [1]  # Handle failure

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

Aexecute_compensation()

Bcommit_transaction()

Cstart_transaction()

Dignore_error()

Attempts:

3 left

💡 Hint

Common Mistakes

Committing the transaction on failure.

Ignoring the error without compensation.

When a step fails, the saga coordinator must execute compensation to undo previous steps.

4fill in blank

hard

Fill both blanks to correctly define a saga step with its compensation.

HLD

def saga_step():
    try:
        [1]  # Perform action
    except Exception:
        [2]  # Perform compensation

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

Aexecute_action()

Bexecute_compensation()

Ccommit_transaction()

Dstart_transaction()

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit_transaction() instead of compensation.

Starting a transaction inside the step incorrectly.

The saga step performs an action and if it fails, it executes compensation to undo.

5fill in blank

hard

Fill all three blanks to define a saga coordinator managing steps and compensation.

HLD

def saga_coordinator():
    [1]  # Start saga
    try:
        [2]  # Execute saga steps
    except Exception:
        [3]  # Execute compensation

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

Astart_transaction()

Bexecute_all_steps()

Cexecute_compensation()

Dcommit_transaction()

Attempts:

3 left

💡 Hint

Common Mistakes

Committing before executing all steps.

Not starting the transaction before steps.

The coordinator starts the saga, executes all steps, and compensates on failure.