Temporal

Eager Workflow Start fallback to non-eager path on worker slot reservation failure

info
availabilityUpdated Mar 3, 2026

When Eager Workflow Start is enabled but the local worker refuses to honor the reserved execution slot, the system automatically falls back to the traditional non-eager workflow start path after WorkflowTaskTimeout expires.

Technologies:
How to detect:

When the first workflow task is returned eagerly but the local worker refuses the reserved slot, the server retries the task non-eagerly after WorkflowTaskTimeout duration.

Recommended action:

1. Monitor for workflows that start with EWS enabled but fall back to non-eager execution. 2. Check worker resource availability and execution slot capacity. 3. Review WorkflowTaskTimeout configuration to ensure appropriate fallback timing. 4. If fallbacks are frequent, investigate worker capacity issues or consider scaling workers. 5. Ensure worker lifecycle management allows proper slot reservation.