Cache variables scope
Cache variables are name value pairs that exist after the flow instance completes execution. Unlike flow variables, cache variables are shared, and are accessible to other flow instances that are running simultaneously. Cache variables work in the same fashion under both flow engine and non-flow engine contexts.
Cache variables stored in external cache store, Redis, are accessible to all flow instances in the current process running simultaneously. All flow and map processes running in the system and across all systems in the network can access cache variables when they are saved in the external cache store. External cache variables persist in the external cache store until they are deleted from the cache.
Internal cache variables on the other hand, persist in the process memory and they go out of scope and are deleted from process memory when the flow or map execution process terminates. The internal cache variables defined, are accessible to all flow or map instances running simultaneously in the flow or map execution process. These variables are not visible to other processes running on the system, or across the system, unlike external cache variables.