Struct SagaExecutor 

pub struct SagaExecutor { /* private fields */ }

Saga forward phase executor

Executes saga steps sequentially during the forward phase. Coordinates with saga store to persist state and handle failures.

Implementations

impl SagaExecutor

pub fn new() -> Self

Create a new saga executor without a saga store

This is suitable for testing. For production, use with_store().

pub fn with_store(store: Arc<PostgresSagaStore>) -> Self

Create a new saga executor with a saga store

This enables persistence of saga state and recovery from failures.

pub fn has_store(&self) -> bool

Check if executor has a saga store configured

pub async fn execute_step( &self, saga_id: Uuid, step_number: u32, mutation_name: &str, _variables: &Value, subgraph: &str, ) -> SagaStoreResult<StepExecutionResult>

Execute a single saga step

Executes a single mutation step within a saga, handling:

• Step state validation (Pending → Executing → Completed)
• @requires field pre-fetching from owning subgraphs
• Entity data augmentation with required fields
• Mutation execution via MutationExecutor
• Result capture and persistence

Arguments

• saga_id - ID of saga being executed
• step_number - Step number to execute (1-indexed, 1 = first step)
• mutation_name - GraphQL mutation operation name
• variables - Input variables for the mutation (JSON value)
• subgraph - Target subgraph name (must exist in federation)

Returns

StepExecutionResult with:

• success: true if step executed successfully
• data: Result entity data if successful
• error: Error description if failed
• duration_ms: Execution time for monitoring

Errors

Returns SagaStoreError if:

• Saga not found in store
• Step already executed (not in Pending state)
• Subgraph unavailable
• Mutation execution fails
• @requires fields cannot be fetched

Example

let executor = SagaExecutor::new();
let result = executor.execute_step(
    saga_id,
    1,
    "createOrder",
    &json!({"customerId": "c123", "total": 100.0}),
    "orders-service"
).await?;

if result.success {
    println!("Order created with data: {:?}", result.data);
} else {
    eprintln!("Step failed: {}", result.error.unwrap());
    // Compensation will be triggered by coordinator
}

pub async fn execute_saga( &self, saga_id: Uuid, ) -> SagaStoreResult<Vec<StepExecutionResult>>

Execute all steps in a saga sequentially

Arguments

• saga_id - ID of saga to execute

Returns

Vector of step results (successful or failed)

pub async fn get_execution_state( &self, saga_id: Uuid, ) -> SagaStoreResult<ExecutionState>

Get current execution state of saga

Arguments

• saga_id - ID of saga

Returns

Current execution state including completed steps

Trait Implementations

impl Default for SagaExecutor

fn default() -> Self

Returns the “default value” for a type.