Directory Server does not load plug-ins dynamically. Instead, you must restart the server. Directory Server then registers your plug-in at startup.
Set logging so Directory Server logs plug-in informational messages with the dsconf set-log-prop error level:err-plugins command. After setting the log level appropriately, restart the server to ensure that it loads the new plug-ins that you configured:
$ dsadm restart instance-path
You can adjust log levels while the server is running.