There are now two new global settings for main.mk that allow limiting the number of monitored hosts and/or services. This option only works when using the Check_MK Micro Core. Example:
cmc_host_limit = 100 cmc_service_limit = 3000
If you now try to activate a configuration with more than 100 hosts or more then 3000 services you will run into an error and the old configuration is being kept. It is also possible to just set a limit on hosts or services. Setting the according variable to None deactivates the limit. This is the default.
This setting can not be changed via WATO. It can be useful in situations where you give access to a user or customer via WATO but want to restrict the amount of objects that he/she can monitor.