Elevator 0.5

On disk key/value store based on levelDB backend

Key-Value store written in Python and based on levelDB, allows high performance on-disk bulk read/write.

Allows async, multithreaded and/or remote access to a multi-leveldb backend.

Relying on the zeromq network library and msgpack serialization format, it is made to be portable between languages and platforms.

See Documentation for more details

Depends on

• zmq-3.X
• pyzmq (built with zmq-3.X)
• leveldb
• plyvel

Installation

The easy way:

pip install elevator

The hacker way:

$ pip install fabric
$ fab build
$ pip install -r requirements.txt
$ python setup.py install

Usage

When elevator is installed, you can then launch the server using the elevator executable. Note that a –daemon option is disposable, and allows you to run elevator server as a daemon, storing it’s pid in .pid file in /tmp.

See config/elevator.conf for an example of Elevator configuration.

Example:

$ elevator --help
usage: elevator -h

Elevator command line manager

optional arguments:
    -h, --help       show this help message and exit
    -d, --daemon      Launch elevator as a daemon
    -c, --config      Path to elevator server config file, eventually
    -t, --transport   Transfert protocol (tcp | ipc)
    -b, --bind        Ip to bind server to
    -p, --port        Port the server should listen on
    -w, --workers     How many workers should be spawned (Threads with concurrent access to all the db store)
    -P, --paranoid    If option is set, Elevator will shutdown and log on first unhandled exception

Clients

Python: py-elevator

Go: go-elevator (Early early, so early version)

Clojure : Coming soon

C : Coming soon

Thanks

Thanks to srinikom for its leveldb-server which was a very good base to start from.

n.n.n / 2013-02-01

• Remove: legacy setup_loggers function
• fix #123: exposing a database object
• ref #123: Renamed DatabasesHandler to DatabaseStore
• Fix: elevator benchmarks
• Fix: supervisor test should remove their tests files
• Add: tests for backend atm
• Add: backend supervisor tests + fixes
• update: enhance backend majordome management
• fix #125: backend does not instantiate it’s own DatabasesHandler anymore
• Fix: elevator tests fakers now uses a clear files/dirs pattern
• Update: more obvious DatabaseHandler args names
• Add: benchmarks using hurdles and pyelevator
• update #120 : Auto re-mount unmounted database on new requests
• Fix : backend properly tears down workers
• fix #120, fix #91: Implement Majordom watcher thread
• Update #120: set databases last access marker
• Update 120: move ocd worker to backend module
• Update #121: implement last activity action on workers
• Update #121: Documented worker
• Update #121: Workers poll to reduce cpu usage + backend refactoring
• Update #121: use an internal message protocol between supervisor and workers
• Update: Moved the backend elements in their own module
• Fix #122: workers now set their processing state
• Refactor: moved loggers init in their own log module
• Update #121: fixed workers stop action
• Update #121: Added constants to normalize interaction with workers
• Add #121: basic workers supervisor implementation, implies a lot of refactoring
• Update: rename server poller
• Update: use ROUTER/DEALER terminology and rename workerpool and proxy to backend and frontend
• Update: renamed conf module to args

0.4b / 2013-01-28

• Fix: Refactor api tests
• Fix #119: Range and Slice now support include_key, and include_value params
• Remove: max cache management + Add: Lru cache and bloom filters

0.4a / 2013-01-22

• Add : Implement PING command
• Add : Cli module
• Add : Debian packaging files
• Update: Use plyvel leveldb backend
• Update: Use plyvel bloom filter in read operations
• Update: Add experimental command line doc
• Update: Set fabfile as a module
• Update: Documentation to fit with plyvel
• Update #114: Run MGet against db snapshot
• Update : working cmdline
• Fix #114: Enhance MGET perfs by acting on a min/max keys range slice
• Fix #113: handle MGET arguments in command line
• Many other little updates and fixes, see logs

0.4 / 2012-10-22

• Add: restore theme
• Add : Base sphinx documentation
• Update : new License MIT
• Fix #86: IOError when bad config file supplied as cmdline argument
• Fix #95: Elevator will start and log errors even though some databases are corrupted
• Fix : log-level debug messages format
• Fix : travis, tests, requirements

0.3d / 2012-10-19

• Add : Request error for invalid request messages
• Update #91: Mount default at server startup
• Update #91: Mount/Unmount command + auto-mount on connect
• Update #91: add a ticker class, which executes a function every x seconds
• Update #30, Update #99: Compress Responses on demande (request.meta[‘compression’])
• Update #88, Update #99: now responses comes in two parts header+content
• Update #88: Fix MGet, Range, Slice return values types to suite with new responses format
• Update #88: Refactored Request/Responses format
• Update : Refactored DatabasesHandler internal storage
• Update : Few refactoring on loggers handling
• Update : Refactored DBConnect no more db_uid to provide in request
• Fix #97: provide mono-letters args
• Fix #89: Log requests/responses on log-level=DEBUG
• Fix #87: Refactored logging
• Fix #100: Non blocking workers, graceful shutdown == PERFORMANCES
• Fix #98: Activity logging on both file and stdout
• Fix #101: fixed ipc handling
• Fix : api tests for compatibility with new Req/Resp
• Fix : refactored tests for new Range/Slice behavior when size == 1
• Fix : Mount/Unmount passed args