At least for me that page comes up blank so 
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What OH offers is the Remote openHAB Addon which will let you mirror the Items defined in an other OH instance in another instance.
It also has MQTT Event Bus [4.0.0.0;4.9.9.9] which will pub/sub Item states and commands to a structured MQTT topic hierarchy that another OH instance (or something else entirely) can pub/sub to/from.
If you are looking for something like load balancing or automatic failover or something like that, OH provides nothing out of the box to support that.