Ellis lists several performance optimizing, spring cleaning and operational changes that stand out in Cassandra 2.0 in his post, including that Java 7 is now required and streaming has been rewritten to be more transparent and robust. Cassandra 2.0 also removes emergency memory pressure valve logic. “The intent here was to give operators enough breathing room to fix misconfigurations causing heap pressure, but it was never as reliable as we would have liked. And now that the important storage engine metadata has been moved off-heap, memory shortages will be obvious much earlier,” Ellis wrote.
ASF officials said the Apache Cassandra developer community includes some of the brightest minds in big data. Hundreds of organizations, from startups to large-scale enterprises such as Adobe, Cisco and IBM, rely on Cassandra to power their mission-critical applications online.
"At Ooyala, we're building some of our most ambitious projects to date on top of Apache Cassandra," said Al Tobey, tech lead for compute and data services at Ooyala, said in a statement. "The maturation of CQL3, vnodes, and new features such as the PAXOS-backed compare-and-set (CAS) added in Cassandra 2.0 will help us build and deploy those projects confidently."
Apache Cassandra is used by many highly visible organizations such as Accenture, CERN, Cloudkick, Comcast, Constant Contact, Dell, Digg, Ericsson, Eventbrite, GoDaddy, Houghton Mifflin Harcourt, HP, Instagram, Intuit, Mahalo, Microsoft MetricsHub, Morningstar, NASA, Netflix, Nextag, OpenWave, PBS Kids, Pitney Bowes, Plaxo, Polyvore, Real Networks, Reddit, Sony Network Entertainment, SoundCloud, Spotify, Squidoo, Stormpath, Symantec, Twitter, Wildfire, WSO2, and ZoomInfo. A listing of where Apache Cassandra is used and deployment details can be found here.
"Paying down a lot of the technical debt accumulated over five years of intense open-source development, and solidifying the Native Binary Transport for CQL 3, has put the project on a great footing," said Aaron Morton, an Apache Cassandra committer and co-founder and principal consultant of The Last Pickle, in a statement. "The addition of Lightweight 'Compare-and-Set' transactions and cursors brings another set of features that make it easier for developers to harness the performance and scale of Cassandra. And the experimental Trigger support will allow open-source contributors to provide feedback for this often-requested feature."
"It'll be really helpful to have conditional updates built into Cassandra," said Jon Haddad, senior architect at Shift, in a statement. "Right now there's a few places where we have to use external locking to manage isolation, and having built in support in the database will be amazing."