Moneta: A unified interface for key/value stores¶ ↑
Moneta provides a standard interface for interacting with various kinds of key/value stores. Moneta supports the well-known NoSQL and document based stores.
A short overview of the features:
-
Supports a lot of backends with consistent behaviour (See below)
-
Allows a full configuration of the serialization -> compression -> adapter stack using proxies (Similar to Rack middlewares)
-
Configurable serialization via
Moneta::Transformer
proxy (Marshal/JSON/YAML and many more) -
Configurable value compression via
Moneta::Transformer
proxy (Zlib, Snappy, LZMA, …) -
Configurable key transformation via
Moneta::Transformer
proxy
-
-
Expiration for all stores (Added via proxy
Moneta::Expires
if not supported natively) -
Atomic operations
-
Atomic incrementation and decrementation for most stores (Method
#increment
and#decrement
) -
Atomic creation of entries (Method
#create
) -
Shared/distributed database-wide synchronization primitives
Moneta::Mutex
andMoneta::Semaphore
-
-
Includes a simple pure-ruby key/value server (
Moneta::Server
) and client (Moneta::Adapters::Client
) -
Integration with Rails, Rack}[http://rack.github.com/]/{Rack-Cache, Sinatra and Ramaze.
If you are not yet convinced, you might ask why? What are the goals of the project?
-
Get people started quickly with key/value stores! Therefore all the adapters are included in the gem and you are ready to go. Tilt does the same for template languages.
-
Make it easy to compare different key/value stores and benchmark them
-
To hide a lot of different and maybe complex APIs behind one well-designed and simple Moneta API
-
Give people a starting point or example code to start working with their favourite key/value store. Feel free to copy code, please mention Moneta then :)
-
Create a reusable piece of code, since similar things are solved over and over again (Rails brings its own cache stores, and many frameworks do the same…)
Moneta is tested thoroughly using Travis-CI.
Getting started¶ ↑
Install Moneta via Rubygems
~~~ $ gem install moneta ~~~
or add it to your Gemfile
~~~ ruby gem 'moneta' ~~~
Now you are ready to go:
~~~ ruby require 'moneta'
Create a simple file store¶ ↑
store = Moneta.new(:File, :dir => 'moneta')
Store some entries¶ ↑
store = 'value'
Read entry¶ ↑
store.key?('key') # returns true store # returns 'value'
store.close ~~~
Links¶ ↑
-
Source: github.com/minad/moneta
-
Tests and benchmarks: travis-ci.org/minad/moneta
-
API documentation:
-
Latest Gem: rubydoc.info/gems/moneta/frames
-
GitHub master: rubydoc.info/github/minad/moneta/master/frames
-
Supported backends¶ ↑
Out of the box, it supports the following backends. Use the backend name
symbol in the Moneta constructor (e.g.
Moneta.new(:Memory)
).
-
Memory:
-
In-memory store (
:Memory
) -
LRU hash - prefer this over :Memory! (
:LRUHash
) -
LocalMemCache (
:LocalMemCache
) -
Memcached store (
:Memcached
,:MemcachedNative
and:MemcachedDalli
)
-
-
Relational Databases:
-
DataMapper (
:DataMapper
) -
ActiveRecord (
:ActiveRecord
) -
Sequel (
:Sequel
) -
Sqlite3 (
:Sqlite
)
-
-
Filesystem:
-
Key/value databases:
-
Berkeley DB using DBM interface or NDBM (Depends on Ruby environment) (
:DBM
) -
Cassandra (
:Cassandra
) -
Daybreak (
:Daybreak
) -
GDBM (
:GDBM
) -
HBase (
:HBase
) -
LevelDB (
:LevelDB
) -
Redis (
:Redis
) -
Riak (
:Riak
) -
SDBM (
:SDBM
) -
KyotoCabinet (
:KyotoCabinet
) -
TokyoCabinet (
:TokyoCabinet
) -
TokyoTyrant (
:TokyoTyrant
) -
Simple Samba database TDB (
:TDB
)
-
-
Document databases:
-
Moneta network protocols:
-
Other
-
Fog cloud storage which supports Amazon S3, Rackspace, etc. (
:Fog
) -
Storage which doesn't store anything (
:Null
)
-
Some of the backends are not exactly based on key/value stores, e.g. the relational ones. These are useful if you already use the corresponding backend in your application. You get a key/value store for free then without installing any additional services and you still have the possibility to upgrade to a real key/value store.
Backend feature matrix¶ ↑
NOTE: <a name=“backend-matrix”>The backend matrix</a> is much more readable on rubydoc.info than on github. Go there!
Adapter | Required gems | Multi-thread safe[1] | Multi-process safe[2] | Atomic increment[8] | Atomic create[9] | Native expires[3] | Persistent | Description |
---|---|---|---|---|---|---|---|---|
Persistent stores | ||||||||
Mongo | mongo | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | MongoDB database |
Redis | redis | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | Redis database |
ActiveRecord | activerecord | ✓ | ✓ | ✓ | ✓ | ✗ | ✓ | ActiveRecord ORM |
File | - | ✓ | ✓ | ✓ | ✓ | ✗ | ✓ | File store |
Sequel | sequel | ✓ | ✓ | ✓ | ✓ | ✗ | ✓ | Sequel ORM |
TokyoTyrant | tokyotyrant or ruby-tokyotyrant | ✗ | ✓ | ✓ | ✓ | ✗ | ✓ | TokyoTyrant database |
PStore | - | ✗ | ✓[10] | ✓ | ✓ | ✗ | ✓ | PStore store |
YAML | - | ✗ | ✓[10] | ✓ | ✓ | ✗ | ✓ | YAML store |
Sqlite | sqlite3 | ? | ✓[10] | ✓ | ✓ | ✗ | ✓ | Sqlite3 database |
Daybreak | daybreak | ✗ | (✓)[7] | ✓ | ✓ | ✗ | ✓ | Incredibly fast pure-ruby key/value store Daybreak |
DBM | - | ✗ | ✗ | ✓ | ✓ | ✗ | ✓ | Berkeley DB using DBM interface or NDBM (Depends on Ruby environment) |
GDBM | - | ✗ | ✗ | ✓ | ✓ | ✗ | ✓ | GDBM database |
LevelDB | leveldb | ✗ | ✗ | ✓ | ✓ | ✗ | ✓ | LevelDB database |
SDBM | - | ✗ | ✗ | ✓ | ✓ | ✗ | ✓ | SDBM database |
TDB | tdb | ✗ | ✗ | ✓ | ✓ | ✗ | ✓ | TDB database |
KyotoCabinet | kyotocabinet | ✗ | ✗ | ✓ | ✓ | ✗ | ✓ | KyotoCabinet database |
TokyoCabinet | tokyocabinet | ✗ | ✗ | ✓ | ✓ | ✗ | ✓ | TokyoCabinet database |
DataMapper | dm-core, dm-migrations | ✓ | ✓ | ✗ | ✓ | ✗ | ✓ | DataMapper ORM |
Couch | faraday, multi_json | ✗ | ✓ | ✗ | ✓ | ✗ | ✓ | CouchDB database |
HBase | hbaserb | ? | ✓ | ✓ | ✗ | ✗ | ✓ | HBase database |
Cassandra | cassandra | ? | ✓ | ✗ | ✗ | ✓ | ✓ | Cassandra distributed database |
LocalMemCache | localmemcache | ✓ | ✓ | ✗ | ✗ | ✗ | ✓ | LocalMemCache database |
Fog | fog | ? | ✓ | ✗ | ✗ | ✗ | ✓ | Fog cloud store |
Riak | riak-client | ✗ | ✓ | ✗ | ✗ | ✗ | ✓ | Riak database |
Non persistent stores | ||||||||
MemcachedDalli | dalli | ✓ | ✓ | ✓ | ✓ | ✓ | ✗[4] | Memcached database with Dalli library |
Memcached | dalli or memcached | ? | ✓ | ✓ | ✓ | ✓ | ✗[4] | Memcached database |
MemcachedNative | memcached | ✗ | ✓ | ✓ | ✓ | ✓ | ✗[4] | Memcached database with native library |
Cookie | - | ✗ | (✓)[6] | ✓ | ✓ | ✓ | ✗ | Cookie in memory store |
LRUHash | - | ✗ | (✓)[6] | ✓ | ✓ | ✗ | ✗ | LRU memory store |
Memory | - | ✗ | (✓)[6] | ✓ | ✓ | ✗ | ✗ | Memory store |
Null | - | ✓ | ✓ | ✗ | ✗ | ✗ | ✗ | No database |
Client | - | ✗ | ✓ | ?[5] | ?[5] | ?[5] | ?[5] | Moneta client adapter |
RestClient | faraday | ✗ | ✓ | ✗ | ✗ | ✗ | ?[5] | Moneta REST client adapter |
-
[1]: Make adapters thread-safe by using
Moneta::Lock
or by passing the option:threadsafe => true
toMoneta#new
. There is alsoMoneta::Pool
which can be used to share a store between multiple threads if the store is multi-process safe. I recommend to add the option:threadsafe
to ensure thread-safety since for example under JRuby and Rubinius even the basic datastructures are not thread safe due to the lack of a global interpreter lock (GIL). This differs from MRI where some adapters might appear thread safe already but only due to the GIL. -
[2]: Share a Moneta store between multiple processes using
Moneta::Shared
(See below). -
[3]: Add expiration support by using
Moneta::Expires
or by passing the option:expires => true
toMoneta#new
. -
[4]: There are some servers which use the memcached protocol but which are persistent (e.g. MemcacheDB, Kai, IronCache, Roma and Flare)
-
[5]: Depends on server
-
[6]: Store is multi-process safe because it is an in-memory store, values are not shared between multiple processes
-
[7]: Store is multi-process safe, but not synchronized automatically between multiple processes
-
[8]: If a store provides atomic increment it can be used with
Moneta::Semaphore
. You can add weak#increment
support using theMoneta::WeakIncrement
proxy. -
[9]: If a store provides atomic creation it can be used with
Moneta::Mutex
. You can add weak#create
support using theMoneta::WeakCreate
proxy. -
[10]: Sqlite/YAML/PStore are multiprocess safe, but the performance suffers badly since the whole database file must be locked for writing. Use a key/value server if you want multiprocess concurrency!
Proxies¶ ↑
In addition it supports proxies (Similar to Rack middlewares) which add additional features to storage backends:
-
Moneta::Proxy
andMoneta::Wrapper
proxy base classes -
Moneta::Expires
to add expiration support to stores which don't support it natively. Add it in the builder usinguse :Expires
. -
Moneta::Stack
to stack multiple stores (Read returns result from first where the key is found, writes go to all stores). Add it in the builder usinguse(:Stack) {}
. -
Moneta::Transformer
transforms keys and values (Marshal, YAML, JSON, Base64, MD5, …). Add it in the builder usinguse :Transformer
. -
Moneta::Cache
combine two stores, one as backend and one as cache (e.g.Moneta::Adapters::File
+Moneta::Adapters::Memory
). Add it in the builder usinguse(:Cache) {}
. -
Moneta::Lock
to make store thread safe. Add it in the builder usinguse :Lock
. -
Moneta::Pool
to create a pool of stores as a means of making the store thread safe. Add it in the builder usinguse(:Pool) {}
. -
Moneta::Logger
to log database accesses. Add it in the builder usinguse :Logger
. -
Moneta::Shared
to share a store between multiple processes. Add it in the builder usinguse(:Shared) {}
. -
Moneta::WeakIncrement
andMoneta::WeakCreate
to add#create
and#increment
support without atomicity (weak) to stores which don't support it.
Serializers and compressors (Moneta::Transformer
)¶ ↑
Supported serializers:
-
BEncode (
:bencode
) -
BERT (
:bert
) -
BSON (
:bson
) -
JSON (
:json
) -
Marshal (
:marshal
) -
MessagePack (
:msgpack
) -
Ox (
:ox
) -
TNetStrings (
:tnet
) -
YAML (
:yaml
)
Supported value compressors:
-
LZ4 (
:lz4
) -
LZMA (
:lzma
) -
LZO (
:lzo
) -
Snappy (
:snappy
) -
QuickLZ (
:quicklz
) -
Zlib (
:zlib
)
Special transformers:
-
Digests (MD5, Shas, CityHash, …)
-
Add prefix to keys (
:prefix
) -
HMAC to verify values (
:hmac
, useful forRack::MonetaCookies
)
Moneta API¶ ↑
The Moneta API is purposely extremely similar to the Hash API with a few minor additions. Every method takes also a optional option hash. In order so support an identical API across stores, Moneta does not support iteration or partial matches.
~~~
initialize(options) options differs per-store, and is used to set up the store.¶ ↑
retrieve a key. If the key is not available, return nil.¶ ↑
load(key, options = {}) retrieve a key. If the key is not available, return nil.¶ ↑
fetch(key, options = {}, &block) retrieve a key. If the key is not available, execute the¶ ↑
block and return its return value.
fetch(key, value, options = {}) retrieve a key. If the key is not available, return the value,¶ ↑
[]=(key, value) set a value for a key. If the key is already used, clobber it.¶ ↑
keys set using []= will never expire.
store(key, value, options = {}) same as []=, but you can supply options.¶ ↑
delete(key, options = {}) delete the key from the store and return the current value.¶ ↑
key?(key, options = {}) true if the key exists, false if it does not.¶ ↑
increment(key, amount = 1, options = {}) increment numeric value. This is an atomic operation¶ ↑
which is not supported by all stores. Returns current value.
decrement(key, amount = 1, options = {}) increment numeric value. This is an atomic operation¶ ↑
which is not supported by all stores. Returns current value. This is just syntactic sugar for incrementing with a negative value.
create(key, value, options = {}) create entry. This is an atomic operation which is not supported by all stores.¶ ↑
Returns true if the value was created.
clear(options = {}) clear all keys in this store.¶ ↑
close close database connection.¶ ↑
features return array of features, e.g. [:create, :expires, :increment]¶ ↑
supports?(feature) returns true if store supports a given feature¶ ↑
~~~
Creating a Store¶ ↑
There is a simple interface to create a store using
Moneta.new
. You will get automatic key and value serialization
which is provided by Moneta::Transformer
. This allows you to
store arbitrary Ruby objects. You can tune some options when you call
Moneta.new
. However for very fine tuning use
Moneta.build
.
~~~ ruby store = Moneta.new(:Memcached, :server => 'localhost:11211') store = 'value' store = {:a => 1, :b => 2} store = MarshallableRubyObject.new ~~~
If you want to have control over the proxies, you have to use
Moneta.build
:
~~~ ruby store = Moneta.build do # Adds expires proxy use :Expires
# Transform key using Marshal and Base64 and value using Marshal use :Transformer, :key => [:marshal, :base64], :value => :marshal
# IMPORTANT: adapter must be defined last for the builder to function properly.
# Memory backend adapter :Memory end ~~~
You can also directly access the underlying adapters if you don't want to use the Moneta stack.
~~~ ruby db = Moneta::Adapters::File.new(:dir => 'directory') db = {:a => 1, :b => 2} # This will fail since you can only store Strings
However for Mongo and Couch this works¶ ↑
The hash will be mapped directly to a Mongo/Couch document.¶ ↑
db = Moneta::Adapters::Couch.new db = {:a => 1, :b => 2}
db = Moneta::Adapters::Mongo.new db = {:a => 1, :b => 2} ~~~
Expiration¶ ↑
The Cassandra, Memcached, Redis and Mongo backends support expiration natively.
~~~ ruby cache = Moneta::Adapters::Memcached.new
Or using the builder…¶ ↑
cache = Moneta.build do adapter :Memcached end
Expires in 60 seconds¶ ↑
cache.store(key, value, :expires => 60)
Never expire¶ ↑
cache.store(key, value, :expires => 0) cache.store(key, value, :expires => false)
Update expires time if value is found¶ ↑
cache.load(key, :expires => 30) cache.key?(key, :expires => 30)
Or remove the expiration if found¶ ↑
cache.load(key, :expires => false) cache.key?(key, :expires => 0) ~~~
You can add the expires feature to other backends using the
Moneta::Expires
proxy. But be aware that expired values are
not deleted automatically if they are not looked up.
~~~ ruby
Using the :expires option¶ ↑
cache = Moneta.new(:File, :dir => '…', :expires => true)
or manually by using the proxy…¶ ↑
cache = Moneta::Expires.new(Moneta::Adapters::File.new(:dir => '…'))
or using the builder…¶ ↑
cache = Moneta.build do use :Expires adapter :File, :dir => '…' end ~~~
Atomic operations¶ ↑
Atomic incrementation and raw access¶ ↑
The stores support the #increment
which allows atomic
increments of unsigned integer values. If you increment a non existing
value, it will be created. If you increment a non integer value an
exception will be raised.
~~~ ruby store.increment('counter') # returns 1, counter created store.increment('counter') # returns 2 store.increment('counter', -1) # returns 1 store.increment('counter', 13) # returns 14 store.increment('counter', 0) # returns 14 store.decrement('counter') # returns 13 store = 'Moneta' store.increment('name') # raises an Exception ~~~
If you want to access the counter value you have to use raw access to the
datastore. This is only important if you have a
Moneta::Transformer
somewhere in your proxy stack which
transforms the values e.g. with Marshal
.
~~~ ruby store.increment('counter') # returns 1, counter created store.load('counter', :raw => true) # returns 1
store.store('counter', '10', :raw => true) store.increment('counter') # returns 11 ~~~
Fortunately there is a nicer way to do this using some syntactic sugar!
~~~ ruby store.increment('counter') # returns 1, counter created store.raw # returns 1 store.raw.load('counter') # returns 1
store.raw = '10' store.increment('counter') # returns 11 ~~~
You can also keep the raw
store in a variable and use it like
this:
~~~ ruby counters = store.raw
counters.increment('counter') # returns 1, counter created counters # returns 1 counters.load('counter') # returns 1
counters = '10' counters.increment('counter') # returns 11 ~~~
Atomic create¶ ↑
The stores support the #create
which allows atomic creation of
entries. #create
returns true if the value was created.
~~~ ruby store.create('key', 'value') # returns true store.create('key', 'other value') # returns false ~~~
Shared/distributed synchronization primitives¶ ↑
Moneta provides shared/distributed synchronization primitives which are shared database-wide between all clients.
Moneta::Mutex
allows a single thread to enter a critical
section.
~~~ ruby mutex = Moneta::Mutex.new(store, 'mutex_key')
mutex.synchronize do mutex.locked? # returns true
# Synchronized access to counter store += 1 end
begin mutex.lock mutex.locked? # returns true # … ensure mutex.unlock end ~~~
Moneta::Semaphore
allows max_concurrent
threads
to enter a critical section.
~~~ ruby semaphore = Moneta::Semaphore.new(store, 'semaphore_counter', max_concurrent)
semaphore.synchronize do semaphore.locked? # returns true # … end
begin semaphore.enter semaphore.locked? # returns true # … ensure semaphore.leave end ~~~
Weak atomic operations¶ ↑
If an underlying adapter doesn't provide atomic #create
or
#increment
and #decrement
you can use the proxies
Moneta::WeakIncrement
and Moneta::WeakCreate
to
add support without atomicity.
But then you have to ensure that the store is not shared by multiple
processes and thread-safety is provided by Moneta::Lock
.
Syntactic sugar and option merger¶ ↑
For raw data access as described before the class
Moneta::OptionMerger
is used. It works like this:
~~~ ruby
All methods after 'with' get the options passed¶ ↑
store.with(:raw => true).load('key')
You can also specify the methods¶ ↑
store.with(:raw => true, :only => :load).load('key') store.with(:raw => true, :except => [:key?, :increment]).load('key')
Syntactic sugar for raw access¶ ↑
store.raw.load('key')
Access substore where all keys get a prefix¶ ↑
substore = store.prefix('sub') substore = 'value' store # returns nil store # returns 'value'
Set expiration time for all keys¶ ↑
short_lived_store = store.expires(60) short_lived_store = 'value' ~~~
Add proxies to existing store¶ ↑
You can add proxies to an existing store. This is useful if you want to compress only a few values for example.
~~~ ruby compressed_store = store.with(:prefix => 'compressed') do use :Transformer, :value => :zlib end
store = 'this value will not be compressed' compressed_store = 'value will be compressed' ~~~
Framework Integration¶ ↑
Inspired by redis-store there exist integration classes for Rails and Rack}[http://rack.github.com/]/{Rack-Cache. You can also use all the Rack middlewares together with Rails and the Sinatra framework. There exist the following integration classes:
-
Rack, Rails and Sinatra
-
Rack::Session::Moneta
is a Rack middleware to use Moneta for storing sessions -
Rack::MonetaStore
is a Rack middleware which places a Moneta store in the environment and enables per-request caching -
Rack::MonetaCookies
is a Rack middleware which uses Moneta to store cookies -
Rack::MonetaRest
is a Rack application which exposes a Moneta store via REST/HTTP -
Rack::Cache::Moneta
provides meta and entity stores for Rack-Cache
-
-
Rails
-
Ramaze
Rack¶ ↑
Session store¶ ↑
You can use Moneta as a Rack session store. Use it in your
config.ru
like this:
~~~ ruby require 'rack/session/moneta'
Use only the adapter name¶ ↑
use Rack::Session::Moneta, :store => :Redis
Use Moneta.new¶ ↑
use Rack::Session::Moneta, :store => Moneta.new(:Memory, :expires => true)
Use the Moneta builder¶ ↑
use Rack::Session::Moneta do use :Expires adapter :Memory end ~~~
Moneta middleware¶ ↑
There is a simple middleware which places a Moneta store in the Rack
environment at env['rack.moneta_store']
. It supports
per-request caching if you add the option :cache => true
.
Use it in your config.ru
like this:
~~~ ruby
Add Rack::MonetaStore somewhere in your rack stack¶ ↑
use Rack::MonetaStore, :Memory, :cache => true
run lambda { |env| env # is a Moneta store with per-request caching }
Pass it a block like the one passed to Moneta.build¶ ↑
use Rack::MonetaStore do use :Transformer, :value => :zlib adapter :Cookie end
run lambda { |env| env # is a Moneta store without caching } ~~~
REST server¶ ↑
If you want to expose your Moneta key/value store
via HTTP, you can use the Rack/Moneta REST service. Use it in your
config.ru
like this:
~~~ ruby require 'rack/moneta_rest'
map '/moneta' do run Rack::MonetaRest.new(:Memory) end
Or pass it a block like the one passed to Moneta.build¶ ↑
run Rack::MonetaRest.new do use :Transformer, :value => :zlib adapter :Memory end ~~~
Rack-Cache¶ ↑
You can use Moneta as a Rack-Cache store. Use it
in your config.ru
like this:
~~~ ruby require 'rack/cache/moneta'
use Rack::Cache, :metastore => 'moneta://Memory?expires=true', :entitystore => 'moneta://Memory?expires=true'
Or used named Moneta stores¶ ↑
Rack::Cache::Moneta = Moneta.build do use :Expires adapter :Memory end use Rack::Cache, :metastore => 'moneta://named_metastore', :entity_store => 'moneta://named_entitystore' ~~~
Cookies¶ ↑
Use Moneta to store cookies in Rack. It uses the
Moneta::Adapters::Cookie
. You might wonder what the purpose of
this store or Rack middleware is: It makes it
possible to use all the transformers on the cookies (e.g.
:prefix
, :marshal
and :hmac
for
value verification).
~~~ ruby require 'rack/moneta_cookies'
use Rack::MonetaCookies, :domain => 'example.com', :path => '/path' run lambda { |env| req = Rack::Request.new(env) req.cookies #=> is now a Moneta store! env #=> is now a Moneta store! req.cookies #=> retrieves 'key' req.cookies = 'value' #=> sets 'key' req.cookies.delete('key') #=> removes 'key' [200, {}, []] } ~~~
Rails¶ ↑
Session store¶ ↑
Add the session store in your application configuration
config/environments/*.rb
.
~~~ ruby require 'moneta'
Only by adapter name¶ ↑
config.cache_store :moneta_store, :store => :Memory
Use Moneta.new¶ ↑
config.cache_store :moneta_store, :store => Moneta.new(:Memory)
Use the Moneta builder¶ ↑
config.cache_store :moneta_store, :store => Moneta.build do use :Expires adapter :Memory end ~~~
Cache store¶ ↑
Add the cache store in your application configuration
config/environments/*.rb
. Unfortunately the Moneta cache store doesn't support matchers. If
you need these features use a different server-specific implementation.
~~~ ruby require 'moneta'
Only by adapter name¶ ↑
config.cache_store :moneta_store, :store => :Memory
Use Moneta.new¶ ↑
config.cache_store :moneta_store, :store => Moneta.new(:Memory)
Use the Moneta builder¶ ↑
config.cache_store :moneta_store, :store => Moneta.build do use :Expires adapter :Memory end ~~~
Advanced¶ ↑
Build your own key value server¶ ↑
You can use Moneta to build your own key/value
server which is shared between multiple processes. If you run the following
code in two different processes, they will share the same data which will
also be persistet in the database shared.db
.
~~~ ruby require 'moneta'
store = Moneta.build do use :Transformer, :key => :marshal, :value => :marshal use :Shared do use :Cache do cache do adapter :LRUHash end backend do adapter :GDBM, :file => 'shared.db' end end end end ~~~
If you want to go further, you might want to take a look at
Moneta::Server
and Moneta::Adapters::Client
which
are used by Moneta::Shared
and provide the networking
communication. But be aware that they are experimental and subjected to
change. They provide an acceptable performance (for being ruby only), but
don't have a stable protocol yet.
You might wonder why I didn't use DRb to implement server and client - in fact my first versions used it, but with much worse performance and it was real fun to implement the networking directly :) There is still much room for improvement and experiments, try EventMachine, try Kgio, …
ToyStore ORM¶ ↑
If you want something more advanced to handle your objects and relations,
use John Nunemaker's ToyStore which works
together with Moneta. Assuming that
Person
is a ToyStore::Object
you can add
persistence using Moneta as follows:
~~~ ruby
Use the Moneta Redis backend¶ ↑
Person.adapter :memory, Moneta.new(:Redis) ~~~
Testing and Benchmarks¶ ↑
Testing is done using Travis-CI. Currently we support Ruby 1.8.7 and 1.9.3.
Benchmarks for each store are done on Travis-CI for each build. Take a look there to compare the speed of the different key value stores for different key/value sizes and size distributions. Feel free to add your own configurations! The impact of Moneta should be minimal since it is only a thin layer on top of the different stores.
How to contribute?¶ ↑
Always feel free to open an issue on github.com/minad/moneta/issues if something doesn't work as you expect it to work. Feedback is also very welcome!
My only request about patches is that you please try to test them before submitting.
Contribute an adapter¶ ↑
If you want support for another adapter you can at first at it to the list of missing adapters at github.com/minad/moneta/issues/16
If you choose to implement an adapter please also add tests. Usually you
only have to add a few lines to script/generate-specs
to
generate appropriate tests for your adapter. Please check also if
travis.yml needs changes, for example if you need to start additional
services.
Check if the default settings in Moneta#new are appropriate for your adapter. If not specify a better one.
Don't forget to edit the README.md and the CHANGES.
Alternatives¶ ↑
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Horcrux: Used at github, supports batch operations but only Memcached backend
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ActiveSupport::Cache::Store: The Rails cache store abstraction
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Padrino::Cache::Store: The Padrino cache store abstraction. Padrino is currently considering switching to Moneta, see github.com/padrino/padrino-framework/pull/1018
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ToyStore: ORM mapper for key/value stores
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ToyStore Adapter: Adapter to key/value stores used by ToyStore, Moneta can be used directly with the ToyStore Memory adapter
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Cache: Rubygem cache wraps Memcached and Redis
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Ramaze::Cache: Cache stores of the Ramaze framework with support for LocalMemCache, Memcached, Sequel, Redis, …
Authors¶ ↑
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Originally by Yehuda Katz and contributors