What is over replication in Hadoop?
Similarly, you may ask, what is replication in Hadoop?
Replication factor in HDFS is the number of copies of a file in file system. A Hadoop application can specify the number of replicas of a file it wants HDFS to maintain. This information is stored in NameNode.
Secondly, where is replication factor in Hadoop? For changing the replication factor across the cluster (permanently), you can follow the following steps:
- Connect to the Ambari web URL.
- Click on the HDFS tab on the left.
- Click on the config tab.
- Under "General," change the value of "Block Replication"
- Now, restart the HDFS services.
Thereof, what is under replication and over replication?
I think you are aware that by default replication factor is 3. Over-replicated blocks are blocks that exceed their target replication for the file they belong to. Under-replicated blocks are blocks that do not meet their target replication for the file they belong to.
Why is replication done in HDFS?
What is the need of Replication in HDFS – Hadoop Distributed File System. Replication in HDFS increases the availability of Data at any point of time. If any node containing a block of data which is used for processing crashes, we can get the same block of data from another node this is because of replication.