Communities play an important role throughout the modern world and arise in numerous scenarios ranging from traffic monitoring to identifying criminal activity cells in social networks. Most interconnected datasets exhibit clusters of strongly interconnected data. Our parallel Louvain algorithm helps uncover accurate communities many times faster than the original sequential code. This makes it suitable for environments where data is distributed geographically besides centralized high performance clusters.
The objectives of this algorithm are two folded:
- Quickly unfold highly accurate communities on large potentially distributed graphs
- Allow a hierarchical view of the communities which enables several levels of detail depending on the needed granularity, e.g., individual level, city level, country level
The algorithm is beneficial to data scientists seeking fast community discovery and analysis on geographically distributed datasets at various levels of detail.
The algorithm has been tested using MPI on an HPC cluster consisting of 16 nodes with 8 cores per node. Each node consisted of two Quad-core AMD Opteron 2376 2.3GHz processors. Speed-ups of up to 6x have been observed for synthetic community graphs consisting of up to 16M vertices and 60M edges.
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To use the algorithm on a given data set:
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Required
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Familiarity with Linux
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Manipulating graph data (potentially to convert the given data to the Metis graph format)
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Ability to run MPI programs on a single node or cluster depending on graph size
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Good to have
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To use the quick start guide, familiarity with Virtual Box and virtualization
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C++
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MPI Library
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To setup the environment on a cluster
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Cluster administration knowledge
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Setting up MPI environment on cluster
The algorithm is hosted at the git hub repository at https://github.com/usc-cloud/parallel-louvain-modularity
Clone the repository using
git clone https://github.com/usc-cloud/parallel-louvain-modularity.git
Note: You may need to install a git client to download the repository.
Given the wide spread adoption of the cloud based frameworks a Map Reduce version of the proposed algorithm was implemented as well and is available here
A quick start guide can be found here together with a precompiled VM to help you get started.
A detailed guide on how to install the software on a distributed setup can be found here.