add requirements.

README.md

@@ -2,3 +2,24 @@ chronosdb
 =========
 
 Scalable datastore for metrics, events, and real-time analytics
+
+Requirements
+------------
+
+* horizontal scalable
+* http interface
+* udp interface (low priority)
+* persistent
+* metadata for time series
+* perform functions quickly (count, unique, sum, etc.)
+* group by time intervals (e.g. count ticks every 5 minutes)
+* joining multiple time series to generate new timeseries
+* dynamic schema
+* filter/query language (sql subset) with where clauses
+* support multiple databases with read/write api key
+* single time series should scale horizontally (no hot spots)
+* dynamic cluster changes and data balancing
+* pubsub layer
+* continuous queries (keep connection open and return new points as they arrive)
+* Delete ranges of points from any number of timeseries (that should reflect in disk space usage)
+* querying should support one or more timeseries (possibly with regex to match on)