What methods can ensure data consistency during transactions distributed across multiple microservices?

The following approaches are used to ensure data consistency in distributed transactions between microservices:

• Two-Phase Commit (2PC) — a classic protocol that guarantees transaction atomicity but is complex and slow, rarely used in microservices due to high coupling.

• Sagas — a pattern that breaks down a transaction into a series of local transactions with compensating actions. If one transaction fails, compensating actions are performed to rollback changes.

• Idempotent operations and retries — to ensure resilience and consistency in case of failures.

• Using message brokers and event-driven architecture — for asynchronous coordination of state between services.

In Go, sagas can be implemented using libraries or manually, managing local transactions and compensating calls.

An example of a simplified saga:

func ProcessOrder() error {
    err := ReserveInventory()
    if err != nil {
        return err
    }
    err = ChargePayment()
    if err != nil {
        CompensateInventory() // rollback reservation
        return err
    }
    return nil
}

Thus, sagas are the most practical and common method for ensuring consistency in distributed microservices.