SAF Simulation

This modified version of the SAF simulator is designed to allow the SAF storage scheme to run as a module independently of the simulation runner logic.

The previous version of this implementation involved putting this repository into the scratch folder in NS-3, this is no longer the case. This module is designed to be placed in the contrib folder so it can be used as its own module and can be run independently of my simulation runner code.

This NS-3 scratch simulator code that attempts to implement the SAF data storage scheme and reproduce the performance evaluation as described in:

T. Hara, :Effective replica allocation in ad hoc networks for improving data accessibility" Proceedings IEEE INFOCOM 2001. Apr. 2001

Motivation

As part of my masters work as part of the Gillis Lab group¹ I am evaluating existing data storage schemes that does not have any available implementations to evaluate. A challenge that our lab group discovered is that there although there have been a number of works published that focus on developing new, better algorithms very little work has been done to evaluate the ones that exist, largely due to challenges around replicating the studies or reproducing the algorithms.

The goal of this implementation is to be able to have a baseline to compare other data storage schemes too (since there are none that are readily available and Hara's methods have been the defacto standard that others are compared to).

Note: Hara implemented their algorithm using a custom built simulator, we have chosen to implement it using the popular NS-3 network simulator instead.

Prereqs:

Not sure if there are others but on ubuntu:

• sqlite3, libsqlite3-dev

If building netanim:

• qt4-qmake
• libqt4-dev

(additionally, on ubuntu 20.10, you need to add an additional repo because qt4 no longer ships with it)

• https://launchpad.net/~gezakovacs/+archive/ubuntu/ppa

Building this project

Reproducibility is one of the key goals of simulator studies.

1. Download and build copy of the ns-3.32 all-in-one distribution.

   wget https://www.nsnam.org/release/ns-allinone-3.32.tar.bz2
   tar xjvf ns-allinone-3.32.tar.bz2
   cd ns-allinone-3.32
   python3 ./build.py --enable-examples

2. Change directories to the contrib/ folder of the ns-3.32 source distribution.

   cd ns-3.32/contrib/

3. Clone this repository.

   git clone git@github.com:marshallasch/saf.git saf

4. Change directory back to the ns-3.32 folder of the source distribution and re-configure ./waf so it can cache the new changes

   cd ..
   ./waf configure --enable-examples --enable-tests
   ./waf build

5. Run the example simulation that is included within the module.

   ./waf --run 'saf-example'

6. Create your own simulations using the SAF module. This is done the same way you would run any other simulation using NS-3. Setup your nodes, add a mobility model, install the SAF application using the helper, then run the simulation.

   One this to note is that the current implementation does not separate the SAF validation simulation from the base SAF implementation that can then be used in other applications, that is a work in progress.

Running the simulation

If you're familiar with ns-3, then you should know that the simulation is run via the waf build tool. Arguments to this program must be part of the same string that is passed to ./waf --run (that's just how it works 🤷).

Every parameter of the simulation is configurable. Run the following to see all the configurable parameters. The default values are as described in the SAF paper cited at the top of this document.

./waf --run 'saf-example --printHelp'  # <-- mind the quotes!

You can view an animation of the simulation using NetAnim, which is included with the ns-3 all-in-one distribution. To do so, run the following:

./waf --run 'saf-example --animation-xml=path/to/saf.xml'

This will generate an XML file at the specified path. You can then open this file with NetAnim to view what happens during the simulation run.

NOTE: currently the generation of the animation has been disabled to improve the run time

Code style

This project is formatted according to the .clang-format file included in this repository. It intentionally deviates from the code style used by the ns-3 library and simulator developers.

The code can be formatted using the included python script created by Guillaume Papin ([@Sarcasm]) and can be found Sarcasm/run-clang-format.

The following command can be run to automatically reformat the code in place according the included style guideline.

./run-clang-format.py -r -i --style file .

Special Thanks

I would like to acknowledge the amazing work that was done by Keefer Rourke (@keeferrourke) on the initial RHPMAN project that I used as a base for this implementation.

License

While ns-3 is itself licensed under the GNU General Public License v2, the code in this repository is made available under the Internet Systems Consortium (ISC) License.

A copy of this license is included in this repository, and embedded in the top of each source file.