Was thinking about how to "unsubscribe" of the infrastucture any unused server in a multi server architecture. Once the ldap master changed, you would delete the old server of the infrastructure not only the references of the old server within each server's configuration.
For exemple i still have reference within ldap of the unused server, still have the unused server shown in the servers' state web gui and so on...

Trying to delete the server using the following command gave me the foolowing error:

zmprov ds ldap1.domain.com

[] INFO: I/O exception (java.net.ConnectException) caught when processing request: Connection refused
[] INFO: Retrying request
ERROR: zclient.IO_ERROR (invoke Connection refused, server: localhost) (cause: java.net.ConnectException Connection refused)