No, HDFS will not move blocks to new nodes automatically. However, newly created files will likely have their blocks placed on the new nodes. You need to run Balancer on NameNode to re-balance the cluster.
Please check that SSH service is enabled on remote machine and credentials provided are correct.
Yes, all cluster components like NameNode, DataNode, ResourceManager, NodeManager, host must work on different ports for single host machine. Adding more that one node will require changing port settings.
You need to add IP to hostname mapping in your host's /etc/hosts file. Administrative privileges are required to edit /etc/hosts file.
This problem might be due to ports used by QueryIO are blocked by firewall. All ports used by QueryIO must be open from firewall.
In a typical Hadoop cluster, total number of files grows to the order of millions over a period of time. Thus with multiple NameNodes having millions of files each, HDFS cluster storage scales horizontally but the namespace does not. In order to scale the name service horizontally, NameNode federation uses multiple independent namespaces. The Namenodes are federated, that is, the Namenodes are independent and don't require coordination with each other. The datanodes are used as common storage for blocks by all the federated Namenodes. Each datanode registers with all the Namenodes in the cluster. QueryIO supports configuration of one database instance per namespace to support NameNode Federation. User can define a database configuration and link it to a namespace. All the metadata / tags associated with the data in given namespace is stored in this linked in database. This feature is required only if user need to use Analytics query feature.
This happens after you have changed configuration properties for NameNode. You need to restart NameNode by first stopping NameNode and then start NameNode. Same is valid for all cluster components. (NameNode, DataNode, ResourceManager, NodeManager).
A common cause for this is the Hadoop service isn't running. Make sure all your cluster components are running. You can see status of all components on Dashboard view.
The only purpose of the secondary name-node is to perform periodic checkpoints.
The secondary name-node periodically downloads current name-node image and edits log files, joins them into new image and uploads the new image back to the (primary and the only) name-node.
So if the name-node fails and you can restart it on the same physical node then there is no need to shutdown data-nodes, just the name-node needs to be restarted.
If you cannot use the old node anymore you will need to copy the latest image somewhere else. The latest image can be found either on the node that used to be the primary before failure if available; or on the secondary name-node.
The latter will be the latest checkpoint without subsequent edits logs, that is the most recent name space modifications may be missing there. You will also need to restart the whole cluster in this case.
Check for the forward slash '/' at the top of data browser, clicking on this this lead you to the root location.
This problem might occur if any of your NameNode or DataNode is stopped. Please make sure your NameNode and DataNode are running.
E-mail is sent to the Email IDs of all registered users. Please write the Email IDs carefully while creating user accounts.
You need to configure notification settings to get email alerts.
For production setup you should consider having Static IPs to your machines, while for a standalone setup where all servers are configured on same host please follow these steps: