Comment 2 for bug 853955

Initially we considered making the aggregation method a parameter of the storage schema for this very reason but the problem is that there is (in general) little correspondence between the ways storage schemas are defined and the way aggregation methods are defined. For example, often times users configure their storage schemas based on how frequently they collect data, which varies by data source not by data type (ie. you might collect all your apache metrics minutely, but for request and and latency metrics you'd want different aggregation methods). So the solution we decided on (but haven't yet implemented) is to have a separate configuration file that defines what aggregation methods should be applied to metrics matching certain patterns. That way your storage-schemas.conf can define storage schemas for "applications.apache.*" while your aggregation-rules.conf (or whatever) might define sum aggregation for '.*requests' and average aggregation for '.*latency', etc.