[UNOMI-817] past event conditions can generate mapping explosions

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: unomi-2.5.0
• Assignee: Jonathan Sinovassin-Naïk
• Reporter: Romain Gauthier
• Created: 23/Nov/23 00:20
• Updated: 11/Jun/24 13:44
• Resolved: 11/Jun/24 13:44

Description

For past event conditions, we add a property eventTriggered+md5 to the profile and session indexes.
But these properties are never cleaned even if the th condition doesn't exist anymore.

This can result in a large number of properties getting added to the index, and could lead to a mapping explosion.

Tech notes: 

• These properties need to be moved to a nested or flattened property (ensure it performs well and that each eventTrigger doesn't NOT create a new mapping, we need only one mappping for all eventTriggered)
• pastEventQueryBuilder, pastEventConditionEvaluator, setEventOccurenceCount action need to be updated 
• If there is a way to prevent these properties to be copied to the session, that would be great
• Requires a migration script, including a full reindexation of the profiles to clean previous mappings