redis_fdw

Very cool, and awesome on opensourcing the agentredrabbit code! We had a somewhat simpler but related "tons of data coming in via RESTful services and don't want to flood directly to the db with massive parallel connections" issue and solved it with Redis likewise. Since we used postgres as the backend, we (http://www.ivc.com) actually sponsored a project create a Redis FDW: https://github.com/pg-redis-fdw/redis_fdw so we could batch up 1,000s of inserts into a single database insert, thus reducing IO to disk.

There is a Redis foreign data wrapper (https://github.com/pg-redis-fdw/redis_fdw) so you can access Redis from PostgreSQL. The new 9.3 adds writable FDW so you could even write to Redis from Postgres when the adapter supports it. Redis is a good complement to Postgres. It provides caching and fast, non-persistent data store, while Postgres is the durable database.