[S4-142] Deep cloning for triggers is needed upon a new PE instance’s creation

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.6
• Fix Version/s: 0.7
• Assignee: Unassigned
• Reporter: Kurtt.Lin
• Created: 08/Sep/13 14:05
• Updated: 08/Sep/13 15:11

Description

The createPE(String id) method in ProcessingElement returns a cloned instance of the prototype. However, the way an instance's triggers map is cloned is incorrect:

pe.triggers = Maps.newHashMap(triggers);

It's a shallow cloning; every instance shares the same trigger for a certain event type.

Or, if the eventCount/lastTime in a trigger is shared across the instances by design, then checkAndUpdate() should be guarded to prevent parallel writing.