When running a number of Load Balanced Registries, it is recommended that a single Registry is the primary server and the rest are secondary servers.
When a Registry is running in "Secondary Server" mode, certain tasks are not performed. In particular when using Fusion Portal to perform CRON jobs, "secondary server" Registries do not perform the CRON jobs of obtaining structures and data. This prevents unnecessary synchronization tasks being performed.
By way of example: if there are 3 Registries, one of which is primary, and the other two are secondary, when the primary performs a CRON job to get data from an external server, the primary Registry obtains the data, loads it into its store then the other 2 Registries (via the load-balance mechanism) notice that there is a change and so automatically obtain the data. If none were secondary servers, all 3 Registries would request the data from the external store and then persist it to their own stores. Each Registry would then signal a change and more work is required to sync the Registries with each other.
To set a Registry into "secondary server" mode, the JVM running it should be supplied with the system property:
Read more about System Properties here .