The purpose of this paper is to find all the instances of a given set of pattern graphs (sub-graphs) in a large data graph using a single round of Map-Reduce. For the simplest pattern graphs like a triangle and rectangle we propose the solution. This paper enumerates complex pattern graphs using the enumeration of simple pattern graphs. We proposed Dominating set based graph partition, it generates non-overlapped sub-graphs. Each sub-graph is processed by one machine in the cluster. We analyze both the communication cost and the total computational cost. Communication cost is reduced by using Map-Reduce based dominating set graph partition. At the same time Multiple pattern (sub-graphs) graphs can be enumerated with the same communication cost. The proposed method is not always superior to the conventional sub-graph enumeration, but in some cases involving large-scale data where this method wins, including (1) Adjacency list representation of the graph is the input (2) Number of partitions are decided based on the graph size. We experimentally show that our approach decreases significantly the computation cost, communication cost and scales the enumeration process with a large graph database.

Graphs have become increasingly important in modeling structures with broad applications like Chemical informatics, Bioinformatics, Web page retrieval and World Wide Web. Frequent graph pattern mining plays an important role in many data mining tasks to find interesting patterns from graph databases. Among different graph patterns, frequent substructures are the very basic patterns that can be discovered in a collection of graphs. We extended the problem of mining frequent subgraph patterns to the problem of mining sequential patterns in a graph database. In this paper, we introduce the concept of Sequential Graph-Pattern Mining and proposed two novel algorithms SFG(Sequential Frequent Graph Pattern Mining) and TCSFG(Top-k Closed Sequential Frequent Graph Pattern Mining). SFG generates all the frequent sequences from the graph database, whereas TCSFG generates top-k frequent closed sequences. We have applied these algorithms on synthetic graph database and generated top-k frequent graph sequences.

Mining frequent and infrequent itemsets from a given dataset is the most important field of data mining. When we mine frequent and infrequent itemsets simultaneously, infrequent itemsets become very important because there are many valued negative association rules in them. Mining frequent Itemset is highly expensive, if the minimum threshold is low, whereas mining infrequent itemsets is highly expensive, if the minimum threshold is high. When the dataset size is very large, both memory usage and computational cost of mining infrequent items is very expensive. In addition, single processor’s memory and CPU resources are not enough to handle very large datasets. Parallel and distributed computing are effective approaches to handle large datasets. In this paper we proposed a method based on Hadoop-MapReduce model, which can handle massive datasets in mining infrequent itemsets. Experiments are performed on 8 node cluster with a synthetic dataset. The performance study shows that the proposed method is efficient in handling very large datasets.