What do you mean by the high availability of a NameNode in Hadoop HDFS?

The HDFS NameNode High Availability feature enables you to run redundant NameNodes in the same cluster in an Active/Passive configuration with a hot standby. This eliminates the NameNode as a potential single point of failure (SPOF) in an HDFS cluster.

How do I enable high availability in HDFS?

1. Step 1: Configure a Repository.
2. Step 2: Install JDK.
3. Step 3: Install Cloudera Manager Server.
4. Step 4: Install Databases. Install and Configure MariaDB. Install and Configure MySQL. Install and Configure PostgreSQL.
5. Step 5: Set up the Cloudera Manager Database.
6. Step 6: Install CDH and Other Software.
7. Step 7: Set Up a Cluster.

What is the difference between a federation and high availability?

The main difference between HDFS High Availability and HDFS Federation would be that the namenodes in Federation aren’t related to each other. While in case of HDFS HA, there are two namenodes – Primary NN and Standby NN.

What do you mean by the high availability of a NameNode how is it achieved?

High availability of a NameNode can be achieved by configuring the Passive stand by node in the cluster along with the Primary running node. Passive Node keeps persistent file system name space along with the in memory metadata.

What is High availability in big data?

The high availability feature in Hadoop ensures the availability of the Hadoop cluster without any downtime, even in unfavorable conditions like NameNode failure, DataNode failure, machine crash, etc. It means if the machine crashes, data will be accessible from another path.

What is HDFS High availability overcome the drawback of NameNode as SPOF?

What is high availability in Hadoop? Hadoop 2.0 overcomes this SPOF shortcoming by providing support for multiple NameNodes. It introduces Hadoop 2.0 High Availability feature that brings in an extra NameNode (Passive Standby NameNode) to the Hadoop Architecture which is configured for automatic failover.

What is Federation in big data?

HDFS Federation improves the existing HDFS architecture through a clear separation of namespace and storage, enabling generic block storage layer. It enables support for multiple namespaces in the cluster to improve scalability and isolation.

What is YARN architecture?

YARN stands for “Yet Another Resource Negotiator“. YARN architecture basically separates resource management layer from the processing layer. In Hadoop 1.0 version, the responsibility of Job tracker is split between the resource manager and application manager.

What is high availability in big data?

What is failover and fencing?

Now I’m going to add a method to the created fence device and add hosts in to it. # ccs -h 172.16.1.250 –addmethod Method01 172.16.1.222 # ccs -h 172.16.1.250 –addmethod Method01 172.16.1.223. You have to add the methods you have created while ago for the both nodes you have in your setup.

What is fencing in Hadoop?

A fencing method is a method by which one node can forcibly prevent another node from making continued progress. This might be implemented by killing a process on the other node, by denying the other node’s access to shared storage, or by accessing a PDU to cut the other node’s power.