moxi - memcached + integrated proxy

(pronunciation: rhymes with foxy)

Source Code

• http://github.com/steveyen/moxi

Features

• Open-source, same BSD license as memcached.
• Written in C.
• Based on the latest memcached server code for its high-performance connection and protocol handling.
• Uses the libmemcached for its rich hashing features (consistent hashing, etc).
• Uses libevent for both upstream (client) and downstream connection handling.

• Test suites
• moxi aims to pass all the relevant memcached server compatibility tests.
• moxi has many new test cases to exercise proxy-only features and topologies.

• Protocol support
• memcached text protocol, for upstream and downstream communication
• memcached binary protocol, for downstream communication
• later:
• binary support for upstream communication
• mixing and matching protocols (eg, some downstream servers are text, some are binary).

• Optimizations
• Multi-get Escalation and Protocol Pipelining - de-duplicates requests for popular keys, based on ideas from Dustin Sallings' spymemcached Java client library for memcached. See: http://code.google.com/p/spymemcached/wiki/Optimizations
• Minimal locks - our aspiration is to have no new locks as part of the "main loop" of protocol handling.
• Timeouts - set maximum time for operations. eg, "no downstream memcached operation should take more than X ms."

• Lots of statistics tracked.
• Statistics are tracked without extra locks, independently on each thread, optimized for the 99% case of being a good proxy. A once-in-awhile request for proxy statistics does an internal scatter-gather to aggregate statistics.

• Live reconfiguration
• Separate management channel (in the works) to allow dynamic server pool reconfigurations.

• Simplified deployment
• Assuming you run moxi on your web/app server boxes, your development, staging and production configurations gets easy: always point your memcached clients to "localhost:11211" (or whatever port you run moxi on).

• Features inherited from memcached
• moxi still has all the same code of memcached, and passes all the tests that memcached passes, so you can use moxi as a memcached server if you wish.
• Multi-platform
• Multi-threaded
• Daemonizable
• Run as another user
• Bindable to IP interface, default is INADDR_ANY
• PID file
• etc