Chapter 5. Persistence Using Redis and MongoDB

It is often necessary to store tuples in a persistent data store, such as a NoSQL database or a fast key-value cache, in order to perform additional analysis. In this chapter, we will revisit the Twitter trending analysis topology from Chapter 4, Example Topology – Twitter with the help of two popular persistence media: Redis and MongoDB.

Redis (http://redis.io/) is an open source and BSD-licensed advanced key-value cache and store. MongoDB is a cross-platform, document-oriented database (https://www.mongodb.org/).

Here are the two problems that we will solve in this chapter:

• Finding the top trending tweet topics using Redis
• Computing hourly aggregates of city mentions using MongoDB