Assignment deduplication

Each invocation of the get*Assignment methods triggers the logging callback function. If you have connected it to transmit events to your Data Warehouse, this will store duplicate data and increase associated costs unnecessarily.

Eppo's SDK deduplicates assignment events using an internal cache that takes into account changes in subject variations and other factors to ensure one and only one canonical event is transmitted.

Since your client likely only handles a single subject, memory pressure should not be a concern and the cache attempts to store all flags for the subject; our goal is to completely eliminate duplicate events.

For servers, the assignment cache is implemented with a configurable-sized Least Recently Used ("LRU") cache. Depending on the available memory on your server instance and perceived variabilty of your subject pool, it can be tuned as desired. The aim is to remove most duplicate events.

This behavior is enabled by default and no action is required beyond upgrading to the supported version.

Supported SDKs

This functionality is available in the Javascript and React Native clients.

Server support is available in NodeJS and GoLang.