The master server needs to be configured so that it can perform ssh communication with itself without a password.
Furthermore, in a master server replicated configuration, also configure so that the primary master server and the secondary master server can use ssh communications with each other without a password.
Create a public key on both the primary master server and the secondary master server so that ssh connection between the two occurs with root permissions and does not require a password.
See
Refer to the help for the ssh-keygen command for information on how to create a public key.
Note
When starting or stopping the Hadoop of this product, Hadoop communicates via ssh.
Furthermore, the content of the definitions files on the master server need to be matched with the various servers during Hadoop setup and DFS file system configuration. In this document, the procedure is to copy the definition files on the master server using scp.
Be aware that prompts for the password are displayed when using ssh/scp.
The following shows whether ssh connections between the servers require root permission.
Connected server | ||||||
|---|---|---|---|---|---|---|
Master server | Slave server | Development | Collaboration | |||
Primary | Secondary | |||||
Initiating | Primary master server | Y (*1) | Y (*1) | Y (*2) | Y | Y |
Secondary master server | Y (*1) | Y (*1) | Y (*2) | N | N | |
Slave | Y | N | - | N | N | |
Development | Y | N | N | - | N | |
Collaboration | Y | N | N | N | - | |
Y: Required
N: Not required
*1: It is necessary to be able to perform ssh connection without a password
*2: The master server communicates via ssh with the slave servers when starting and stopping Hadoop, therefore a prompt will be displayed for each slave server if you do not make the settings for ssh connection without a password
