How is the distance between two nodes defined in Hadoop?

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How is the distance between two nodes defined in Hadoop?

The distance between two nodes is the minimum number of edges to be traversed to reach one node from another.

How is network distance calculated in Hadoop?

Let’s count distance between any circle and its parent as 1. Then the distance between any two circles is the sum of their distance to their closest common ancestor or 0 for the same node. So it’s always 6 for any two nodes in different data centers (like between /d1/r1/n1 and /d2/r4/n10).

What is the distance between nodes on different racks in the same data center?

distance(/d1/r1/n1, /d1/r2/n3) = 4 (nodes on different racks in the same data center) distance(/d1/r1/n1, /d2/r3/n4) = 6 (nodes in different data centers)

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How do you find the number of nodes in Hadoop cluster?

1 Answer

  1. Here is the simple formula to find the number of nodes in Hadoop Cluster?
  2. N = H / D.
  3. where N = Number of nodes.
  4. H = HDFS storage size.
  5. D = Disk space available per node.
  6. Consider you have 400 TB of the file to keep in Hadoop Cluster and the disk size is 2TB per node.
  7. Number of nodes required = 400/2 = 200.

What does Network topology receive as input?

A network topology is the physical and logical arrangement of nodes and connections in a network. Nodes usually include devices such as switches, routers and software with switch and router features. Network topologies are often represented as a graph.

How do you calculate data nodes?

Formula to calculate HDFS nodes Storage (H)

  1. H = C*R*S/(1-i) * 120\%
  2. Example:
  3. Number of data nodes (n): n = H/d = c*r*S/(1-i)/d.
  4. RAM Considerations:

How does Hadoop ensure fault tolerance?

HDFS is highly fault-tolerant. Before Hadoop 3, it handles faults by the process of replica creation. HDFS also maintains the replication factor by creating a replica of data on other available machines in the cluster if suddenly one machine fails. Hadoop 3 introduced Erasure Coding to provide Fault Tolerance.

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Which topology allows equal access to each node?

❖ The ring network does not subject to signal loss problem as a bus network experiences. ❖ There is no termination because there is no end to the ring. Advantages: 1) Each node has equal access.