Stitch is a wrapper around a Cassandra database. It has a web application that provides read-access to the counts through an HTTP API. The counts are written to Cassandra in two distinct ways, and it's possible to use either or both of them:

• Real-time: For real-time updates, Stitch has a processor application that handles a stream of events coming from a broker and increments the appropriate counts in Cassandra.

• Batch: The batch part is a MapReduce job running on Hadoop that reads event logs, calculates the overall totals, and bulk loads this into Cassandra.

HazelCast is the foundation for the distributed system that hosts our APIs and intelligent workflows. We wrap the core HazelCast functions in Clojure protocols to implement micro-services on top of a coherent, single-process instance per virtual node.

Cassandra is our data management workhorse. It handles all our key-value services, supports time-series data storage and retrieval, securely stores all our audit trails, and backs our Datomic database.

As part of the cacheing system within Drupal.

Memcached mainly took care of creating and rebuilding the REST API cache once changes had been made within Drupal.

Distributed cache exposed through Google App Engine APIs; use to stage fresh data (incoming and recently processed) for faster access in data processing pipeline.

While we experimented with Cassandra in the past, we are no longer using it. It is, however, open for consideration in future projects.

We are using Cassandra in a few of our apps. One of them is as a count service application to track the number of shares, clicks.. etc

Memcache caches database results and articles, reducing overall DB load and allowing seamless DB maintenance during quiet periods.

Datastax interview

Used to cache most used files for our clients. Connected with CloudFlare Railgun Optimizer.

Memcached is used as a simple page cache across the whole application.