Solved! Go to Solution.
Yeah. Make sure you configure the <Scope> element in the PopulateCache policy. When it's configured with a value of Global, the cache key can be looked up from other API proxies that exist in the same environment.
Check out the <Scope> element in the following docs references for PopulateCache and LookupCache policies:
http://apigee.com/docs/api-services/content/populate-cache-policy#element_reference
http://apigee.com/docs/api-services/content/lookup-cache-policy#element_reference