Saga Rollback Behavior

When a saga step fails, compensation actions run in reverse order to undo all completed steps.

Rollback Order

Compensations always run in reverse order of the original steps:

Forward:  Step 1 → Step 2 → Step 3 → Step 4 (fails)
Rollback: Comp 3 → Comp 2 → Comp 1

Compensation Failures

What happens if a compensation itself fails?

Forward:  Step 1 ✓ → Step 2 ✓ → Step 3 ✗
Rollback: Comp 2 ✗ (compensation failed!)

Nexus retries the failed compensation up to 3 times. If it still fails:

  1. The saga is marked as compensation_failed
  2. An alert is generated
  3. Manual intervention is required

Manual Resolution

# Check saga status
naos saga status order-fulfillment

# Retry failed compensation
naos saga retry-compensation order-fulfillment --step 2

# Force mark as resolved
naos saga resolve order-fulfillment --step 2

Partial Rollback

If only some compensations fail, the saga tracks which steps were successfully compensated:

naos saga status order-fulfillment

# Steps:
#   1. reserve-inventory   ✓ completed  ✓ compensated
#   2. charge-payment      ✓ completed  ✗ compensation failed
#   3. ship-order          ✗ failed