To run a session using an FTP connection for an SFTP server that requires public key authentication, the public key and private key files must be accessible on nodes where the session will run.
If the Integration Service is configured to run on primary and backup nodes, make the key files accessible on each node configured to run the Integration Service process.
If the Integration Service is configured to run on a grid, make the key files accessible on each node configured to run on the grid. If you cannot put the files on each node in the grid, create a resource in the domain and assign it to each node where you put the files. When you create a session, configure it to use the resource.
For example, create a custom resource called SFTP. When you create a session, you can require the session to use the SFTP resource. The Load Balancer will only dispatch the session to nodes where the key files are accessible.