Locking Items
When an item is being reviewed by a user, no other user can review the same item. To enforce this, the system locks each item when it is being reviewed.
Duplicate Detect implements a fast image and data retrieval feature. This feature allows a group of work items equal to the preload buffer size to be locked. This property is configurable by the user. When previously retrieved items are unlocked by the lock expiration task, they should be locked again before the user takes any action on the reviewed item or goes to the next item.
To address unusual situations where an item is locked for a long period of time, a lock management page is available. The user selects a namespace on the page and clicks Display locked items. A list of the internal IDs of all locked items, the IDs of the locking users, and the times the locks were acquired is displayed. An unlock icon is provided for each item. The administrator clicks the unlock icon to remove the lock.
- When a user obtains a lock, it is recorded in the session for the user. A user’s session expires after a period of inactivity, which is defined by the time since the last request from the user’s browser. The default time for the expiration is 30 minutes of inactivity, although the WebSphere® administrator can change this value. Refer to the WebSphere Application Server administrative console documentation for instructions on how to change the session timeout for an application. If a user brings up an item for review and does not complete the review, the session may expire. In this case, the lock for the item is automatically cleared when the session expires.
- A user could start a review, thereby obtaining a lock, and the administrator could clear the lock before the review is complete. In this case, a message is displayed to the reviewing user that explains that the lock was removed before the review was completed.
- When a user logs out of the system, any locks they may be holding are released because logging out closes their session and session closure releases locks. The case where the user does not log out, perhaps because they just close their browser after beginning to review an item, relies on the session timeout to release any locks. The recommended practice is to always log out, otherwise unnecessary locks may be held waiting for session timeout to clear them.
- A user can display the details list and another user can select an item on the list to review. In this case, the first user does not see the lock icon if they displayed the list before the second user began their review. If the first user attempts to review the locked item by clicking the magnifying glass, the system displays a message explaining the item is locked by another user.