You should see a progress bar after making service changes. Configuration should be applied when this progress is complete. This usually takes no more than a minute.
Port types are divided into categories for each protocol (TCP, UDP, HTTP). Information on these categories can be found here.
As a basic form of mitigation a rate limit is enforced in regards to the acceptable request rate per connecting client. This rate can be adjusted or disabled in the dashboard. For more information on HTTP Rate Limiting see here.
Contact us. There is many custom algorithms we may be able to apply.