Reverse-Sync is when an action or job is executed inside your VMWare environment (VCSA, VCD, NSX) and Hyalto reflects that change inside the portal. The process however differs depending on the environment. Here are the procedures for each environment and how Reverse-Sync is achieved.
vCloud Director and NSX Edge Gateway
Both vCloud and NSX uses the messaging protocol AMQP to send messages back and forth to Hyalto. These messages tells Hyalto what action to apply to any object whether its power on a VM, delete a vApp or add a firewall rule. It can also show changes made at the System level, for example, adding a datastore, removing a distributed port group, or modifying a external network.
This works only if you have setup Hyalto to use the same AMQP service that vCloud/NSX is using and you are using a different username other than administartor@system.
Please see Create a vCloud Automator for more details.
vCenter Server Appliance
Unlike vCloud and NSX, vCenter does not use a messaging protocol to send out any actions or jobs done by vCenter. So Hyalto has a built-in service that will fetch any changes in vCenter and apply them to Hyalto. The script will run every 15 minutes on the hour (:00, :15, :30, and :45).
So if you power on a VM in vCenter at 7:25pm, the action will reflect in Hyalto at 7:30pm.
This service also works for System actions as well. For example, if you added a datastore at 3:47pm, the new datastore will show up in Hyalto at 4:00pm.