HDFS - Blockreport

Yarn Hortonworks


A blockreport is a list of all HDFS data blocks that correspond to each of the local files, and sends this report to the NameNode.

Each datanode create and send this report to the namenode:

  • when the DataNode starts up (It scans through its local file system)
  • at specified interval ?

A Blockreport contains the list of data blocks that a DataNode is hosting. Each block has a specified minimum number of replicas.


Trigger a block report

with HDFS - DFSAdmin, see the options -triggerBlockReport [-incremental]


Discover More
Hdfs Ui Block Information
HDFS - Block

in HDFS. The block size can be changed by file. Block are stored on a datanode and are grouped in block pool The location on where the blocks are stored is defined in hdfs-site.xml....
Yarn Hortonworks
HDFS - Block Replication

in HDFS HDFS stores each file as a sequence of blocks. The blocks of a file are replicated for fault tolerance. The NameNode makes all decisions regarding replication of blocks. It periodically receives...
Hdfs Datanode Ui
HDFS - Datanode Web UI

datanode Web ui. where you can see: Service Nodes Port Protocol Description DataNode All worker nodes 30075 HTTPS Web UI to view status, logs, etc. URL Each data node...
Yarn Hortonworks
HDFS - File System Metadata

The file system metadata section of HDFS. The NameNode is the repository of all HDFS metadata. The metadata are stored in two files: fsimage file which is the metadata store EditLog transaction...
Yarn Hortonworks
HDFS - NameNode

NameNode is an HDFS daemon that run on the head node. It' s the head process of the cluster that manages: the file system namespace and regulates access to files by clients. The NameNode: executes...

Share this page:
Follow us:
Task Runner