Saga pattern for distributed transactions in Kafka - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Saga pattern in distributed transactions?

The Saga pattern breaks a large transaction into smaller steps, each with a compensating action to undo it if needed. It helps keep data consistent across services without locking resources.

intermediate

How does Kafka help implement the Saga pattern?

Kafka acts as a message broker to send events between services. Each service listens for events, performs its step, and publishes the next event or a compensation event if something fails.

beginner

What is a compensating transaction in the Saga pattern?

A compensating transaction is an action that reverses a previous step if the saga fails later. It helps undo partial changes to keep the system consistent.

intermediate

What are the two main types of Saga implementations?

1. Choreography: Services communicate by producing and consuming events without a central coordinator. 2. Orchestration: A central coordinator tells each service what to do next.

intermediate

Why is the Saga pattern preferred over distributed two-phase commit in microservices?

Saga avoids locking resources and long waits by using asynchronous steps and compensations. It scales better and fits microservices' independent nature.

What role does Kafka play in the Saga pattern?

A Message broker to pass events between services

B Database to store all transactions

C Load balancer for microservices

D Authentication service

Kafka is used as a message broker to send and receive events that coordinate saga steps.

What is a compensating transaction?

A A step that confirms the transaction

B An action that reverses a previous step if needed

C A database commit operation

D A service that starts the saga

Compensating transactions undo previous steps to maintain consistency if the saga fails.

Which Saga implementation uses a central coordinator?

A Two-phase commit

B Choreography

C Orchestration

D Event sourcing

Orchestration uses a central coordinator to direct saga steps.

Why is Saga pattern better than two-phase commit in microservices?

A It avoids resource locking and scales better

B It locks resources longer

C It uses synchronous calls only

D It requires a single database

Saga uses asynchronous steps and compensations, avoiding locks and fitting microservices.

In Saga, what triggers the next step in the transaction?

A A database trigger

B A manual user action

C A timer

D An event published to Kafka

Each service publishes an event to Kafka to trigger the next step.

Explain how the Saga pattern manages distributed transactions using Kafka.

Think about how services talk and undo work if needed.

Describe the advantages of using the Saga pattern over traditional two-phase commit in microservices.

Focus on why Saga suits distributed systems better.