Table of Contents
How does MapReduce algorithm work?
MapReduce algorithm is based on sending the processing node (local system) to the place where the data exists. MapReduce Algorithm works by breaking the process into 3 phases. In MapReduce, each phase has key-value pairs as input and output.
Can BFS be parallelized?
With this bag-structure, parallel BFS is allowed to write the vertexes of a layer in a single data structure in parallel and later efficiently traverse them in parallel.
How does BFS and DFS work?
BFS(Breadth First Search) uses Queue data structure for finding the shortest path. DFS(Depth First Search) uses Stack data structure. 3. BFS can be used to find single source shortest path in an unweighted graph, because in BFS, we reach a vertex with minimum number of edges from a source vertex.
What is MapReduce in MongoDB?
Map-reduce is a data processing paradigm for condensing large volumes of data into useful aggregated results. To perform map-reduce operations, MongoDB provides the mapReduce database command. For those keys that have multiple values, MongoDB applies the reduce phase, which collects and condenses the aggregated data.
What is chain Mapper and chain reducer?
The ChainReducer class allows to chain multiple Mapper classes after a Reducer within the Reducer task. Using the ChainMapper and the ChainReducer classes is possible to compose Map/Reduce jobs that look like [MAP+ / REDUCE MAP*] . And immediate benefit of this pattern is a dramatic reduction in disk IO.
What distributed BFS?
2.2 Distributed BFS with 1-D Partitioning. A 1-D partitioning of a graph is a partitioning of its vertices such that each vertex and the edges emanating from it are owned by one processor. The set of vertices owned by a processor is also called its local vertices.
How do you implement parallel DFS?
Depth First Search in Parallel
- Start with a single thread and do a normal DFS, as this hits a node, spawn a new thread that start with the fail node as the start node and pass to that call the Node travelled so far.
- The initial thread continues in the path of the pass.
What is BFS algorithm in C?
Introduction to BFS algorithm in C BFS is a traversal algorithm that is applied mostly on the graphs to travel from one node to another node for various manipulation and usage. The visit on each node using the BFS algorithm makes the entire algorithm treated as an efficient and useful algorithm.
What is a BFS queue?
Breadth-First Search (BFS) is an algorithm used to traverse through all of the nodes within a graph, tree, etc. It uses a Queue, which is a list of the nodes the algorithm is going to visit, and the algorithm ends when the Queue is empty (indicating that their are no more nodes to be visited).
How to use BFS pseudocode?
BFS pseudocode create a queue Q mark v as visited and put v into Q while Q is non-empty remove the head u of Q mark and enqueue all (unvisited) neighbours of u Python, Java and C/C++ Examples The code for the Breadth First Search Algorithm with an example is shown below.
How to use BFS to traversing a data set?
In the various levels of the data, you can mark any node as the starting or initial node to begin traversing. The BFS will visit the node and mark it as visited and places it in the queue. Now the BFS will visit the nearest and un-visited nodes and marks them. These values are also added to the queue.