PrepAway - Latest Free Exam Questions & Answers

What does the this tell you?

Cluster Summary:
45 files and directories, 12 blocks = 57 total. Heap size is 15.31 MB/193.38MB(7%)

Refer to the above screenshot.
You configure a Hadoop cluster with seven DataNodes and on of your monitoring UIs displays the
details shown in the exhibit.
What does the this tell you?

PrepAway - Latest Free Exam Questions & Answers

A.
The DataNode JVM on one host is not active

B.
Because your under-replicated blocks count matches the Live Nodes, one node is dead, and
your DFS Used % equals 0%, you can’t be certain that your cluster has all the data you’ve written
it.

C.
Your cluster has lost all HDFS data which had bocks stored on the dead DatNode

D.
The HDFS cluster is in safe mode

14 Comments on “What does the this tell you?

  1. sravan says:

    correct answer is A. Because one node is shown as dead meaning that it is not connected to namenode and NN won’t perform any writes to that DN. The command “hadoop dfsadmin -refrshNodes” might help bringing back the node to live.




    0



    0
  2. Chris says:

    Why would B not be the correct answer with the best explanation? We know that “one node is dead” from this display but we do not know exactly the cause. This is why I do not agree with “A”. Only “B” seems to have all correct statements.




    0



    0
  3. Yaro says:

    “DFS Used %” is zero only because overall cluster usage is so low:
    0.144MB (dfs used) / 17330MB (capacity) * 100 = 0,00080784766 %




    0



    0

Leave a Reply

Your email address will not be published. Required fields are marked *