Apache Cassandra - Prominent Users

Prominent Users

• Apixio uses Cassandra to store its Patient Object Model and extracted features about patients and patient populations
• AppScale uses Cassandra as a back-end for Google App Engine applications
• Cisco's WebEx uses Cassandra to store user feed and activity in near real time.
• The CERN ATLAS experiment uses Cassandra to archive its online DAQ system's monitoring information
• Cloudkick uses Cassandra to store the server metrics of their users.
• Constant Contact uses Cassandra in their social media marketing application.
• Digg, a large social news website, announced on Sep 9th, 2009 that it is rolling out its use of Cassandra and confirmed this on March 8, 2010. TechCrunch has since linked Cassandra to Digg 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.
• Facebook used Cassandra to power Inbox Search, with over 200 nodes deployed. This was abandoned in late 2010 when they built Facebook Messaging platform on HBase.
• IBM has done research in building a scalable email system based on Cassandra.
• InWorldz has researched and developed a scalable high-performance storage system for user inventory items Cassandra.
• Netflix uses Cassandra as their back-end database for their streaming services
• Formspring uses Cassandra to count responses, as well as store Social Graph data (followers, following, blockers, blocking) for 26 Million accounts with 10 million responses a day
• Mahalo.com uses Cassandra to record user activity logs and topics for their Q&A website
• Ooyala Built a scalable, flexible, real-time analytics engine using Cassandra
• At Openwave, Cassandra acts as a distributed database and serves as a distributed storage mechanism for Openwave’s next generation 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
• Plaxo has "reviewed 3 billion contacts in database, compared them with publicly available data sources, and identified approximately 600 million unique people with contact info."
• PostRank uses Cassandra as their backend database
• Rackspace is known to use Cassandra internally.
• Reddit switched to Cassandra from memcacheDB on March 12, 2010 and experienced some problems with overload handling in Cassandra in May.
• 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 user account information
• Talentica Software uses Cassandra as a back-end for Analytics Application with Cassandra cluster of 30 nodes and inserting around 200GB data on daily basis.
• Twitter announced it is planning to use Cassandra because it can be run on large server clusters and is capable of taking in very large amounts of data at a time. Twitter continues to use it but not for Tweets themselves.
• Urban Airship uses Cassandra with the mobile service hosting for over 160 million application installs across 80 million unique devices
• @WalmartLabs (previously Kosmix) uses Cassandra with SSD
• Yakaz uses Cassandra on a five-node cluster to store millions of images as well as its social data.
• ZangBeZang uses Cassandra as the datastore for its carrier grade recommendation and marketing platform.
• Zoho uses Cassandra for generating the inbox preview in their Zoho#Zoho_Mail service

Ironically, Facebook moved off its early Cassandra deployment in late 2010 when they replaced Inbox Search with the Facebook Messaging platform. Facebook never deployed an Apache Cassandra release.

Cassandra is the most popular wide column store.