aiomas 0.2.0

A multi-agent system based on asyncio

aiomas – A library for multi-agent systems and RPC based on asyncio

aiomas is an easy-to-use library for remote procedure calls (RPC) and multi-agent systems (MAS). It’s written in pure Python on top of asyncio.

Here is an example how you can write a simple multi-agent system:

>>> import asyncio
>>> import aiomas
>>>
>>> class TestAgent(aiomas.Agent):
...     def __init__(self, container, name):
...         super().__init__(container, name)
...         print('Ohai, I’m %s' % self.name)
...
...     @asyncio.coroutine
...     def run(self, addr):
...         remote_agent = yield from self.container.connect(addr)
...         ret = yield from remote_agent.service(42)
...         print('%s got %s from %s' % (self.name, ret, addr))
...
...     @aiomas.expose
...     def service(self, value):
...         return value
>>>
>>> loop = asyncio.get_event_loop()
>>> c = aiomas.Container(('localhost', 5555))
>>> agents = [c.spawn(TestAgent) for i in range(2)]
Ohai, I’m agent://localhost:5555/0
Ohai, I’m agent://localhost:5555/1
>>> loop.run_until_complete(agents[0].run('agent://localhost:5555/1'))
agent://localhost:5555/0 got 42 from agent://localhost:5555/1
>>> c.shutdown()

aiomas is released under the MIT license. It requires Python 3.4 and above and runs on Linux, OS X, and Windows.

Features

aiomas just puts three layers of abstraction around raw TCP / unix domain sockets provided by asyncio:

Agents and agent containers:

The top-layer provides a simple base class for your own agents. All agents live in a container.

Containers take care of creating agents and performing the communication between them. Only agents in different containers talk via network sockets. Agents within the same container use direct method calls.

The container provides a clock for the agents. This clock can either be synchronized with the real (wall-clock) time or be set by an external process (e.g., other simulators).

RPC:

The rpc layer implements remote procedure calls which let you call methods on remote objects nearly as if they were normal objects:

Instead of ret = obj.meth(arg) you write ret = yield from obj.meth(arg).

Request-reply channel:

The channel layer is the basis for the rpc layer. It sends JSON or MsgPack encoded byte strings over TCP or unix domain sockets. It also maps replies (of success or failure) to their corresponding request.

Although you usually want to use the agent layer, it is perfectly okay to only use the rpc or channel layer.

Planned features

Some ideas for future releases:

• SSL/TLS support for TCP sockets

• Optional automatic re-connect after connection loss

• Helper for binding a socket to a random free port

Installation

aiomas requires Python >= 3.4 and msgpack-python (it may also run on Python 3.3 with the asyncio package, but this is untested).

Install aiomas via pip by running:

$ pip install aiomas

Contribute

• Issue Tracker:

• Source Code:

Set-up a development environment with:

$ pip install -r requirements.txt

Run the tests with:

$ py.test

Support

• Documentation:

• Mailing list:

License

The project is licensed under the MIT license.

Changelog

0.2.0 - 2015-01-23

• [CHANGE] The MsgPack codec is now the default. Thus, msgpack-python is now a mandatory dependency.

• [CHANGE] Renamed RpcClient.call to RpcClient.remote.

• [NEW] aiomas.agent module with an Agent base class and a Container for agents. Agents within a container communicate via direct method calls. Agents in different containers use RPC.

• [NEW] aiomas.clock module which offers various clocks for a MAS:

  • AsyncioClock is a real-time clock and wraps asyncio’s time(), sleep(), call_later() and call_at() functions.

  • ExternalClock can be synchronized with external simulation environments. This allows you to stop the time or let it pass faster/slower than the wall-clock time.

• [NEW] Support for unix domain sockets in aiomas.channel and aiomas.rpc.

• [NEW] “rpc_service()” tasks created by an RPC server can now be collected so that you can wait for their completion before you shutdown your program.

• [NEW] Added contents to the README and created a Sphinx project. Only the API reference is done yet. A tutorial and topical guides will follow.

• [FIX] aiomas with the JSON codec is now compatible to simpy.io

0.1.0 – 2014-12-18

Initial release with the following features:

• A request-reply channel via TCP that allows to send multiple messages and to asynconously wait for results (or an exception).

• Messages can be serialized with JSON or msgpack.

• The underlying communication protocol should be compatible with simpy.io (if you use JSON and no custom serializers).

• Remote procedure calls (RPCs) supporting nested handlers and bidirectional calls (callees can make calls to the caller before returning the actual result).

Authors

The original author of aiomas is Stefan Scherfke.

The development is kindly supported by OFFIS.