Manage Hosts

The hosts are the machines used to run Splunk AppDynamics On-Premises components such as the Controller and Events Service. For example, the Events Service can run on the same host as the Controller, a single host, or a cluster of three or more hosts.

You must properly configure the credential you use to add a new host on a remote host. This means that for a private key that you have specified, you must add the corresponding public key to the remote host ~/.ssh/authorized_hosts file.

The Controller and Events Service must reside on the same local network and communicate by internal network. Do not deploy the cluster to nodes on different networks, whether relative to each other or to the Controller where the Enterprise Console runs. When identifying cluster hosts in the configuration, you will need to use the internal DNS name or IP address of the host, not the externally routable DNS name.

For example, in terms of an AWS deployment, use the private IP address such as 172.31.2.19 rather than public DNS hostname such as ec2-34-201-129-89.us-west-2.compute.amazonaws.com. You must then go to the Appserver Configurations under Controller Settings in the Enterprise Console GUI, and edit the external URL so you can access the page.

The host that runs the Enterprise Console is automatically created and added to the platform as the hostname of the Enterprise Console machine if you use the GUI to install or discover components. If you do not use the GUI, you must manually add this host.

Hosts can be managed through the Enterprise Console GUI on the Hosts page or the command line.

Warning: The id_rsa, RSA private key, should be created using the OpenSSL PEM encoding format over the Open SSH standard encoding.

Set Up Remote Hosts

To set up seamless Enterprise Console communications with remote hosts, perform the following steps:

From the command line:

1. Set up the following passwordless SSH:

  • From the Enterprise Console to the Controller.
  • If HA then:
    • from the Enterprise Console to the primary Controller.
    • from the Enterprise Console to the secondary Controller.
    • From the primary Controller to the secondary Controller.
    • from the secondary Controller to the primary Controller.

From the Enterprise Console:

2. Identify the Enterprise Console Linux user's public/private key pair (usually in ~/.ssh).

3. Add the Enterprise Console Linux user's public key (~/.ssh/id_rsa.pub) into the remote Controller server Linux user's ~/.ssh/authorized_keys.

4. Then chmod 600 /.ssh/authorized_keys.

5. Test the SSH connection from the Enterprise Console server with the following:

ssh <remote user>@<remote-server> hostname

6. Verify that the remote hostname is printed. You may have to first answer yes to trust the server fingerprint.

7. Access the Enterprise Console UI Credential page, and add or edit the existing credentials.

8. Create a single credential, which will likely be the same for all remote hosts, with a name like: EC-<ec linux user name>-<remote appd user name> For example, EC-ecappduser-appduser , or EC-appdyn if the username is the same on the Enterprise Console and remote server.

9. Enter the remote server Linux username. It might be the same as the local Enterprise Console user.

10. Supply the Enterprise Console Linux user's ~/.ssh/id_rsa contents as the private key as chosen in step 2.

Add Hosts

Before you add hosts to the platform, ensure that the required credentials are added to the platform.

Note: You should also check that the user ID created matches those in the credentials. Additionally, the path you specify for the platform base directory must exist.

You can add a host in the GUI by clicking Add.

bin/platform-admin.sh add-hosts --hosts host_1 host_2 host_3 --credential <credential name>

Instead of listing the hosts with --hosts, you can specify a text file with a line-separated list using the following command:

bin/platform-admin.sh add-hosts --host-file <file path to host file> --credential <credential name>

If you do not use the GUI, you must add the host for the Enterprise Console. This is also the host used by the Controller and embedded Events Service. The host is named "localhost" and does not require credentials. For example, run the following command:

Linux
bin/platform-admin.sh add-hosts --hosts localhost
Windows
bin\platform-admin.exe cli add-hosts --hosts localhost
Note: You may also use the loopback address '127.0.0.1' or the machine's actual hostname.

Remove Hosts

Before you remove a host, ensure that you remove all Splunk AppDynamics On-Premises components from the host. You can remove a host in the GUI by selecting the host and clicking Remove.

bin/platform-admin.sh remove-hosts --hosts host_1 host_2 host_3

Instead of listing the hosts with --hosts, you can specify a text file with a line-separated list using the following command:

bin/platform-admin.sh remove-hosts --host-file <file path to host file>

If a host becomes unreachable, you can use the following command to remove it:

bin/platform-admin.sh remove-dead-hosts --hosts <host name> -platform-name <name_of_platform>

This removes the host and all of its associated metadata from the Enterprise Console database.

Warning: Running remove-dead-hosts could leave various services in an inconsistent state.

List Current Hosts

Linux
bin/platform-admin.sh list-hosts
Windows
bin\platform-admin.exe cli list-hosts

Update Host Credentials

Change the credential that the Enterprise Console uses to access hosts. You can change the host credential in the GUI by selecting the host and clicking Change Credentials.

bin/platform-admin.sh update-host-credential --hosts host_1 host_2 host_3 --credential <credential name>

Similar to the add and remove host commands, you can specify a text file instead of providing a list of hosts within the command.