##The Peer-to-Peer Fault-Tolerant Language-Agnostic Computation Dispatcher Over Pooled Self-Organizing Heterogenous Nodes

As part of the Distributed Systems course at the Rochester Institute of Technology, our group started work on Steve, the peer-to-peer computation dispatcher. Steve was formed from the proposal for a system based on the general concept of distributed computation and meshnets. It's goal is to provide fault-tolerant computation for mobile and capability restricted devices.

Steve consists of trusted but self-organizing nodes which maintain their own capability lists so that they can attempt computation requests or forward them on if unable.

In other words, say you don't have a C++ compiler on your smart-phone, or you are running Linux but want to test your code on a Windows 7 OS running python version 2.7. Steve can help you out. Tell him what to find and he'll ask around. When he finds a friend that is capable of doing what you asked he'll let you know and he'll pass on the program or code to run. When the friend gets back to him he'll forward the report to you.

• Fault-tolerant: Steve can have a lot of friends, and if more than one friend can work on your code, then you can let them all have a go. Just in case one is a no-show, the other's will still have your back. Also, in case you are preoccupied, Steve and his friends have a great memory and will let you know what the answer was when you next get a chance.

• Language-Agnostic: Steve's friends don't all have to speak the same language, as long as they all know how to look at a computation request. The request could be for a particular language, or even a particular operating system.

• Self-Organizing: Steve cares about the friends that do him favors. The one's that don't or send him crap gifts, are dropped from his friends list. In other-words, Steve maintains a reputation system and will lower the reputation of friends that send him code that makes him crash or don't return results that others do.

• Heterogenous: Steve isn't expecting all friends to be able to do everything, in fact, Steve counts on the fact that he's so connected to diverse people, that he can get different things done for you. In his network of friends, being unique and useful is a good thing.

• Trust: Steve only talks to his friends. He's clique'ish like that. To be a part of the group Steve will first ask other's opinion of you before ever talking to you. Whitelist first, then rely on reputation later. This can be a problem, especially if a dynamic friend-base is desirable.

• Security: I'm sorry... right now Steve's a loud mouth. The only real security you have in letting Steve do your dirty work, is that he'll let you tell him exactly how to do something. So if you want it sandboxed, he'll use that damn sandbox.

From the feature and fault lists, you can decide if you want to give Steve a try. Check the Building and Deploying sections below. If you think you can add more features or remove some faults, send us a pull request and we'll take a look at it.

The Steve Daemon has only been tested on Mac OS X and Debian Linux. The Windows platform is currently not supported. The Steve Daemon only needs a few things to get started:

• Erlang VM (minimum version R15B01)
• libcap-dev (for erlexec package, to monitor OS processes)

Steve is headless and will need an interface to interact with it. You can use the Erlang shell, or the following GUI:

• Xamarin Steve Client - Uses Xamarin library and can be built for several different platforms including Android.

• Windows Steve Client - A straight up windows client using XAML and C#.

There are two parts that need to be built, the Daemon service that runs in the background, and the Client that you can use to connect and utilize the Daemon. To build both and start working with them, make sure your system meets the requirements above and type make.

• To run the daemon type the following: ./bin/runerl.sh

• And then once the shell opens type: steve:start().

We use the Rebar system to compile our Erlang application releases:

make all

This will create a 'rel' directory that has bundled Steve along with the Erlang VM for transport, just zip/tar it up if you want to move it to another system. To install Steve:

cd ~/bin
ln -s /pathToRel/rel/steve/bin/steve

Steve works like a service:

./bin/steve
Usage: steve {start|stop|restart|reboot|ping|console|attach} 

Once started you can attach to the running service and treat it like an Erlang shell to send commands to it.