How to Check Hadoop Server Name?

To check the Hadoop server name, you can typically navigate to the Hadoop web interface. The server name is usually displayed on the home page of the web interface or in the configuration settings. You can also use command-line tools such as "hadoop fs -ls /" to see information about the Hadoop file system, which may include the server name. Additionally, you can check the Hadoop configuration files on the server to find the server name specified in the settings.

How to extract the Hadoop server name from the Resource Manager?

To extract the Hadoop server name from the Resource Manager in Hadoop, you can try the following steps:

1. Log in to the Resource Manager web interface. Usually, the URL for the Resource Manager web interface is http://:8088, where is the hostname or IP address of the machine where Resource Manager is running.
2. Once you are logged in to the Resource Manager web interface, look for the "Nodes" tab or section. This will display a list of all the nodes in the Hadoop cluster along with their status and details.
3. Find the node that is running the Hadoop server (NameNode) in the list. Typically, the node running the Hadoop server will have a special role like "active namenode" or "standby namenode".
4. Click on the node to view more details. Look for the hostname or IP address of the node, which is typically displayed under the node's details.
5. The hostname or IP address of the node running the Hadoop server is the Hadoop server name.

Alternatively, you can also use the Hadoop command-line tools to extract the Hadoop server name from the Resource Manager. You can run the following command to get a list of active nodes in the cluster:

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yarn node -list

This command will list all the nodes in the cluster along with their details, including the hostname or IP address of the node running the Hadoop server.

What is the procedure for migrating the Hadoop server name to a new node?

To migrate the Hadoop server name to a new node, follow these steps:

1. Prepare the new node: Install the necessary software packages on the new node, including Java and Hadoop. Copy the Hadoop configuration files from the existing node to the new node, including core-site.xml, hdfs-site.xml, and mapred-site.xml.
2. Shut down the Hadoop services on the existing node: Stop the Hadoop daemons using the command stop-all.sh or by stopping each daemon individually.
3. Update the configuration settings on the new node: Update the dfs.namenode.name.dir and dfs.datanode.data.dir properties in the hdfs-site.xml file to point to the correct directories on the new node. Update the mapred.job.tracker property in the mapred-site.xml file to point to the new node.
4. Start the Hadoop services on the new node: Start the Hadoop daemons using the command start-all.sh or by starting each daemon individually.
5. Verify the migration: Check the status of the Hadoop services using the jps command to ensure that they are running on the new node. Run some test jobs to verify that the Hadoop cluster is functioning correctly on the new node.
6. Update any client configurations: If necessary, update the client configurations on other nodes or client machines to point to the new Hadoop server name.

Following these steps will help ensure a successful migration of the Hadoop server name to a new node.

How to identify the Hadoop server name using Ambari?

To identify the Hadoop server name using Ambari, follow these steps:

1. Log in to the Ambari web interface using your credentials.
2. Once logged in, navigate to the "HDFS" section under the "Services" tab on the left-hand menu.
3. In the HDFS summary page, you will see a list of all the nodes in your Hadoop cluster. Look for the node that has the "NameNode" component running on it. This node is typically referred to as the Hadoop server.
4. Click on the NameNode component to view more details about the node, including its hostname and IP address. This will help you identify the server name of the Hadoop server.

Alternatively, you can also go to the "Hosts" tab in Ambari and look for the host that is running the NameNode service. This host is also considered as the Hadoop server.