Table of Contents
moxi was started around Q1 2009 based off the memcached code base. It's current source repository is a http://github.com/couchbase/moxi.
Moxi inherited a lot of machinery from memcached, including:
Networking and connection management
Thread management
Protocol parsing
Startup components
Build environment
From the point of view of moxi's codebase:
upstream -- the client application, or the source of requests
downstream -- the memcached/membase servers which are the destination for requests
Moxi code also uses the word "pool" in a way that predates our modern usage of "cluster", so they are somewhat synonyms.