TWCS is a proposed improvement on DTCS. The motivations for TWCS are explained at:

https://issues.apache.org/jira/browse/CASSANDRA-9666

And:

http://www.slideshare.net/JeffJirsa1/cassandra-summit-2015-real-world-dtcs-for-operators

Checkout the repo:

git clone https://github.com/jeffjirsa/twcs/

Switch to the right version (for newest 2.1 release, for example):

git checkout origin cassandra-2.1

Build the jar:

cd TimeWindowCompactionStrategy
mvn compile
mvn package

The resulting jar will be placed in target/

This repository ( https://github.com/jeffjirsa/twcs ) will be used for standalone TWCS code (simple jar to drop into lib/). For practical purposes, in this repository the compaction strategy is com.jeffjirsa.cassandra.db.compaction.TimeWindowCompactionStrategy .

TWCS is also available as a C* fork (in the hopes that patches are accepted upstream):

2.1: https://github.com/jeffjirsa/cassandra/tree/twcs-2.1

2.2: https://github.com/jeffjirsa/cassandra/tree/twcs-2.2

Trunk / 3.0: https://github.com/jeffjirsa/cassandra/tree/twcs

In the full fork, the compaction strategy is: org.apache.cassandra.db.compaction.TimeWindowCompactionStrategy

TWCS is provided under the Apache License, V2: http://www.apache.org/licenses/LICENSE-2.0