This repository contains parallelized implementations of the five game theoretic centrality algorithms proposed in Tomasz Michalak et al (2013). Please check the publication for more details.

1. M Vishnu Sankar
2. Balaraman Ravindran

1. Ensure that Java 8 is installed in your system. Run java -version to ensure proper installation. If not, please install Java SE Development Kit 8 before proceeding. You can also use OpenJDK if you prefer that.
2. Ensure that you have maven installed. Run mvn -v to ensure proper installation. If not, please install Maven following the official documentation.
3. Clone this repository to your system and change your working directory to the cloned one.
4. Each of the directories named Game{x}, where x = 1, 2, 3, 4, 5 inside src/; contain the source code of the algorithms. Head over to the directories in your cloned repo and run mvn clean package. This will generate the Game{x}-1.0.0.jar.

1. Ensure that Java 8 is installed in your system. Run java -version to enure proper installation. If not, please install Java SE Runtime Environment 8 before proceeding. You can also use OpenJDK if you prefer that.
2. Please download the .jar files from dist/ and follow the Apache Hadoop setup instructions.

1. Please install Apache Hadoop 3.1.1 and configure it according to the official documentation.
2. Ensure hadoop version is displaying the correct version.
3. Also, make sure you have a working HDFS cluster before proceeding.

The .jar files need to be run like so:

$ hadoop jar Game{x}-1.0.0.jar in.ac.iitm.rbcdsai.centrality.Game{x}.Main <hdfs/path/to/input> <hdfs/path/to/output>

where the algorithm to run can be chosen by setting x to be one of {1, 2, 3, 4, 5}.

The input file is basically an adjacency list containing edges of the graph. Each line denotes an edge, whose nodes are separated by a single whitespace as the delimiter.

A few things to also note about the format:

1. No comments or blank lines.
2. No annotations.
3. No explicit mention of total nodes or edges.

For clarity, here's a basic example of what input.txt can be:

1 2
2 3
3 4
4 5

The output directory name will depend on the number of steps required for the respective algorithm to process the input file. For example, Game 1 has two sets of Map-Reduce, and so, the final output file will be in the directory path: <hdfs/path/to/output>2. The output file will have nodes listed along with the respective Shapley value, like so:

1 2.556
2 5.444

Here's an example of running Game 1 on email-EuAll dataset from SNAP, and input file being stored in HDFS, having input path as /usr/hadoop/email-Eu-core.txt and output directory path as /usr/hadoop/email-Eu-core-output:

$ hadoop jar Game1-1.0.0.jar in.ac.iitm.rbcdsai.centrality.Game1.Main '/usr/hadoop/email-Eu-core.txt' '/usr/hadoop/email-Eu-core-output'

If you use the implementations, please cite:

@Article{SANKAR2015,
    author  = "SANKAR, M. VISHNU and RAVINDRAN, BALARAMAN",
    title   = "Parallelization of game theoretic centrality algorithms",
    journal = "Sadhana",
    year    = "2015",
    month   = "Sep",
    day     = "01",
    volume  = "40",
    number  = "6",
    pages   = "1821--1843",
    issn    = "0973-7677",
    doi     = "10.1007/s12046-015-0425-z",
    url     = "https://doi.org/10.1007/s12046-015-0425-z",
}