netislands

copyright (c) 2015 Oliver Flasch. All rights reserved.

Introduction

Netislands is a tiny network library to support highly scalable parallel distributed computing tasks with modest bandwidth and latency demands, such as evolutionary and genetic algorithms, through a model of connected islands. An island is an abstract object supporting the following operations:

1. Init: int island_init(Netislands_Island *island, const int port, const unsigned n_neighbors, const char *neighbor_hostnames[n_neighbors], const int neighbor_ports[n_neighbors], const long max_message_queue_length, const unsigned max_failures) initializes an island listening on port that has outgoing connections to n_neighbors with hostnames neighbor_hostnames (an array of strings) and ports neighbor_ports (an array of ints). Received neighbor messages are stored in a queue of maximum length max_message_queue_length. If this length is exceeded, the oldest message in the queue will be silently dropped when a new message arrives. Set to max_message_queue_length to disable this behavior. Neighbors are considered as failed and will be removed if max_failures send attempt failed. Set this to 0 to disable neighbor removal.
2. Send: int island_send(const Netislands_Island *island, const char *message) sends the string message to all neighbors of an island.
3. Dequeue Message: char *island_dequeue_message(const Netislands_Island *island) dequeues the oldest message from islands message queue and returns it. If no message is present, 0 (NULL) is returned. The caller is responsible to call free() on the message returned after use.
4. Destroy: int island_destroy(Netislands_Island *island) cleanups an island.

The network topology is defined implicitly by the neighborhood relation, enabling very good scalability. New islands announce their presence to their defined neighbors when started, while unreachable neighbors are removed automatically, increasing robustness. After a network of islands has been set up, no central control instance is needed. Islands can freely join and leave the network.

Compatability

Netislands has been tested on Mac OS X 10.10.3. It should also work under Linux and other POSIX-compatible operating systems. Support for Windows is included, but untested.

Installation and Use

Just add the following source files to your project:

• netislands.h
• netislands.c
• queue.h
• queue.c
• tinycthread.h
• tinycthread.c

Then include the Netislands API via #include "netislands.h".

Demo / Test

Netislands contains netislands_test.c, a simple test driver and demo application. It is built via the included Makefile's all target, i.e. by just typing make on the command line.

License

Netislands is copyright (c) 2015 Oliver Flasch and released under the MIT licence. See the file LICENSE for details.

TinyCThread uses the following license:

Copyright (c) 2012 Marcus Geelnard 2013-2014 Evan Nemerson

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.

2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.

3. This notice may not be removed or altered from any source distribution.