The engineering blog of the CUBRID open-source database project, covering Java internals, databases, and scalability, including pieces on LINE's app development.
HN commenters cite it for NoSQL benchmarking and large-scale database technology overviews, using it as a reference in database and JVM garbage collection discussions.
"Some cursory Googling suggests that Java's GC will suspend the main execution thread during each GC op"
The (non-default) CMS and G1 GCs will do as much as they can in background threads before they have to stop the world. For more information see http://www.oracle.com/webfolder/technetwork/tutorials/obe/java/gc01/index.html and http://www.cubrid.org/blog/dev-platform/understanding-java-garbage-collection/. I only know about this because I kept encountering long, GC-related pauses on my Minecraft server that went away when I switched to the concurrent mark-sweep collector. :)
Be careful to compare apples to apples. Sure, the memory-only crowd (e.g, redis) will post higher numbers, but Cassandra is the performance leader for scalable, larger-than-memory datasets. See http://www.cubrid.org/blog/dev-platform/nosql-benchmarking/ for example. (And this tests an old version of Cassandra; we did a lot of optimization on the read path for 1.0: http://www.datastax.com/dev/blog/whats-new-in-cassandra-1-0-performance.)
Other candidates:
* Yahoo's Everest
* Greenplum
* Aster Data
All mentioned here: http://www.cubrid.org/blog/dev-platform/database-technology-for-large-scale-data/
The Register wrote that Amazon's solution is a column-oriented database possibly based on Postgres, like Yahoo's:
http://www.theregister.co.uk/2012/11/28/amazon_aws_redshift_data_warehousing/