Date:February, 2010
Author:  Neal Richter  nrichter@gmail.com
RE: Project MemcacheInnoDB

Project MemcacheInnoDB is inspired and derived from MemcacheDB (http://memcachedb.org/), a version of 
memcached with BerkeleyDB used as a persistent store.  A excellent overview of MemcacheDB is available here:
http://memcachedb.org/memcachedb-guide-1.0.pdf MemcacheDB: A Complete Guide, by Steve Chu.

Here the persistent layer will be replaced with Innodb, specifically embedded-InnoDB.
http://www.innodb.com/products/embedded-innodb
Documentation:  http://www.innodb.com/products/embedded-innodb/documentation/
Source Code:  http://www.innodb.com/products/embedded-innodb/download/
Binaries:   http://www.innodb.com/products/embedded-innodb/download/

No real code yet, but here's the TODO:

Phase 0:
  - [DONE] convert ib_test2.c from InnoDB embedded examples to tests/iv_kvtest.c
  - Hack an open, set, get, and close method by sturying examples & tests from InnoDB source and binary distributions
  - Leave BDB code in to write parallel tables

Phase 1:
  - decide on InnoDB configuration options.  conf file versus CLI options?
  - map or toss each BDB API usage to an InnoDB usage
  - excise the BerkeleyDB code entirely

Phase 2:
  - review threading models for compatibility
  - some work done outside of BerkeleyDB maybe taken care of within InnoDB
     - chkpoint_thread (checkpointing)
     - memp_trickle_thread (dirty page writer)
     - dl_detect_thread  (deadlock detecting)

Phase 3:
  - keep banging on it until it's working well

GOALS for the project:

Provide a memcache compatible storage system based upon the InnoDB embedded library. 
 - keep-it-simple-stupid and let InnoDB handle the hard stuff
 - support transactions and replication
 - provide complete control of all InnoDB configuration options
 - compatibility with InnoDB tools from Innobase Oy and Percona 
 - support multiple tables and spread objects evenly

Features
********
* High performance read/write for a key-value based object
* High reliable persistent storage with transaction
* High availability data storage with replication
* Memcache protocol compatibility

Supported memcache commands
***************************
get(also mutiple get) 
set, add, replace
append/prepend
incr, decr
delete
stats

Unsupported memcache features
***************************
expiration time of objects are ignored

Private commands
****************
???

LIMITATIONS:
 - This will use ONLY simple key-value tables with no secondary indexes
 - If you need something else, use MySQL