Enable inventory locking on low availability

Optimistic lock avoidance

The Optimistic Lock Avoidance (OLA) feature facilitates an active and optimistic locking for an item during scheduling and reservation processes.

The yfs.hotsku.lockOnlyOnLowAvailability property determines whether inventory lock must be avoided until availability gets low in the distribution group that is configured for fulfillment. With Optimistic Lock Avoidance feature, when the application checks availability for the first time, it assumes that all items have high availability and avoids locking. The availability calculation does not lock the YFS_INVENTORY_ITEM record unless a corresponding record exists in the INV_INVENTORY_ITEM_LOCK table for the demand type. Even when a record is created in INV_INVENTORY_ITEM_LOCK table, inventory lock is driven by the PURPOSE value, which is based on the availability status.

Optimistic lock avoidance with granular locking

In addition to locking improvements with Optimistic Lock Avoidance (OLA), the granular locking feature enables locking of item for availability checks only when the availability for an item is low at a node.

If you set the value of the yfs.hotsku.useGranularLockingForItem property to Y, the property determines whether granular locking is enabled with OLA. If enabled, the application assumes that the availability for an item at a node is high. Based on the hot SKU control parameters, if the availability is low, a record is inserted in the INV_INVENTORY_ITEM_LOCK table with PURPOSE values based on the availability status.

It is recommended that you use the yfs.hotsku.assumeUnavailableOnLockTimeout property, which determines whether an item must be assumed as not available, if the lock cannot be acquired. The yfs.hotsku.assumeUnavailableOnLockTimeout property is applicable only when the yfs.hotsku.useTimeOutLocking property is set to Y. If the yfs.hotsku.useTimeOutLocking property is set to Y, and if a timeout occurs, it is assumed that there is no inventory available for this item. It is assumed that inventory is not available for the sourcing rule details. If multiple sourcing rule details are present, the normal expansion continues and lock is again attempted.

The benefit is that it improves the performance of the APIs.

With the new feature enabled, the availability calculation does not apply lock unless a corresponding record exists in the INV_INVENTORY_ITEM_LOCK table for the demand type.

Avoid supply or demand updates from locking the YFS_INVENTORY_ITEM record

To avoid the contention during supply or demand updates, the yfs.hotsku.lockItemOnInventoryChanges property is introduced. By default, the value of this property is set to Y. If this property is set to Y, the inventory item is locked even before making supply or demand updates.

When the yfs.hotsku.lockItemOnInventoryChanges property is set to N, inventory lock is avoided during adjustments. The contention is reduced as the lock contention moves from the item-level to the item-supply or the item-demand level. The overall response time is improved for supply or demand updates as an extra lookup in YFS_INVENTORY_SUPPLY_ADDNL and YFS_INVENTORY_DEMAND_ADDNL is no longer needed. In addition to the reduced lookups, item locking can be avoided. As the lock on YFS_INVENTORY_ITEM no longer occurs, an intrinsic lock is applied at the row level for each supply or demand record.