Register mechanism is no longer required for local / exit span
Since version 6.6.0, SkyWalking has removed the local and exit span registers. If an old java agent (before 6.6.0) is still running, which registers to the 6.6.0+ backend, you will face the following warning message.
class=RegisterServiceHandler, message = Unexpected endpoint register, endpoint isn't detected from server side.
This will not harm the backend or cause any issues, but serves as a reminder that your agent or other clients should follow the new protocol requirements.
You could simply use
log4j2.xml to filter this warning message out.