What is one of the runtime controls available for zabbix_server?

The command "zabbix_server -R config_cache_reload" serves as a runtime control for the Zabbix server that allows for the dynamic reloading of the configuration cache. This is particularly useful when changes are made to the configuration files or when there's a need to update the internal configuration of the Zabbix server without requiring a full restart. By using this command, administrators can ensure that new settings or updates are applied immediately, enhancing flexibility and efficiency in managing the Zabbix environment.

Other options listed may suggest actions related to starting, stopping, or restarting the Zabbix server, but they do not specifically address the reload of the configuration cache. The ability to reload the cache without disrupting the service is essential for maintaining continuous monitoring while still allowing for the application of changes on the fly, making this command a vital tool for Zabbix server management.