Management and Monitoring
Cassandra is a Java-based system that can be managed and monitored via Java management Extensions (JMX). The JMX-compliant node tool utility, for instance can be used to manage a Cassandra cluster (adding nodes to a ring, draining nodes, decommissioning nodes and so on). Node tool also offers a number of commands to return Cassandra metric pertaining to disk usage, latency, compaction, garbage collection, and more.
Since Cassandra 2.0.2 in 2013, measures of several metrics are produced via drop wizard metrics framework, and may be queried via JMX using tools such as Jconsole or passed to external monitoring system via drop wizard compatible reporter plugins.
According to DB Engines Ranking, Cassandra is the most popular wide column store, and in September 2014 became the 9th most popular database.
Apple uses 100,000 Cassandra nodes, as revealed at Cassandra Summit San Francisco 2015, although it has no elaborated for which products services or features.
AppScale uses Cassandra as a back-end for Google App Engine Applications
BlackRock uses Cassandra in their Aladdin investment management platform
CERN used Cassandra based prototype for its ATLAS experiment to archive the online DAQ system's monitoring information
Cisco's webEX uses Cassandra to store user feed and activity in near real time
Constant Contact uses Cassandra in their email and social media marketing applications. Over 200 nodes are deployed.
Digg, a social news website, announced on September 9th that it is rolling out is use of Cassandra and confirmed this on March 8th 2010, TechCrunch has since linked Cassandra to dig V4 reliability criticisms and recent company struggles. Lead engineers at Digg later rebuked these criticisms as red herring and blamed a lack of load testing.
Discord switched to Cassandra to store billions of messages from MongoDB in November, 2015.
FormSpring uses Cassandra to count responses, as well as store social graph data (follower, following, blockers blocking) 26 million account with 10 million responses a day.
Grubhub uses Cassandra as their primary persistent data store for their backend services.
Globo.com uses Cassandra as back-end database for their streaming services.
Mahalo.com used Cassandra record their uses activity logs and topics for their Q&A website.
Netflix uses Cassandra as their back-end database for their streaming services.
Nutanix appliance uses Cassandra to store metadata and stats
Ooyala built a real-time analytics engine using Cassandra
OpenWave uses Cassandra as a distributed database and as a distributed storage mechanism for their messaging platform
OpenX is running over 130 nodes on Cassandra for their openX Enterprise product to store and replicate advertisements and targeting data for ad delivery.
Rackspace uses Cassandra internally
Reddit switched to Cassandra from memcacheDB on March 12, 2010 and experienced some problems in May of that to insufficient nodes in their cluster.
RockYou uses Cassandra to record every single click for 50 million Monthly Active users in real time for their online games
SoundCloud uses Cassandra to store the dashboard of their users.
Uber uses Cassandra to store around 10,000 features in their daily updated company-wide Feature store for latency access during live model predictions
Urban Airship uses Cassandra with the mobile service hosting for over 160 million application installs across 80 million unique devices