James Hamilton has published a thorough summary of Facebook's Cassandra, another scalable key-value store for your perusal. It's open source and is described as a "BigTable data model running on a Dynamo-like infrastructure." Cassandra is used in Facebook as an email search system containing 25TB and over 100m mailboxes. # Google Code for Cassandra - A Structured Storage System on a P2P Network # SIGMOD 2008 Presentation. # Video Presentation at Facebook # Facebook Engineering Blog for Cassandra # Anti-RDBMS: A list of distributed key-value stores # Facebook Cassandra Architecture and Design by James Hamilton
HBase: Bigtable-like structured storage for Hadoop HDFS Just as Google's [WWW] Bigtable leverages the distributed data storage provided by the [WWW] Google File System, HBase provides Bigtable-like capabilities on top of Hadoop Core. Data is organized into tables, rows and columns. An Iterator-like interface is available for scanning through a row range (and of course there is the ability to retrieve a column value for a specific key). Any particular column may have multiple versions for the same row key.
JumboMem provides a low-effort solution to the problem of running memory-hungry programs on memory-starved computers. The JumboMem software gives programs access to memory spread across multiple computers, providing the illusion that all of the memory resides within a single computer. When a program exceeds the memory in one computer, it automatically spills over into the memory of the next computer.