- How many repository server can we have ?
There can be only one active repository database. The repository database is used by all nodes.
- Is there any limitation of node configuration (Central vs secondary)
I don't understand your question. Can you explain in more detail what you want to know
- If repository server located in different region (Japan /Hong Kong /China), what is the sync method.
(provided that we have a 4M connection)
Since there is only one repository database it does not need to be synched.
Perhaps the examples here help: https://help.qlik.com/en-US/sense/September2018/Subsystems/PlanningQlikSenseDeployments/Content/Sense_Deployment/Enterpr…