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A: It is actually the piing time out which controls this factor. The mysql connector property that controls this is "loadBalancePingTimeout".
     Currently this property is not exposed through db.properties so it uses the default pint time out value which is 0(Mean no ping time out)
     (http://dev.mysql.com/doc/connector-j/en/connector-j-reference-configuration-properties.html) 

Q:  What Mysql DB Versions are supported when DB HA is enabled?

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A: The Synchronization between 2 master nodes is immediate and latency is depending on the actual network latency between 2 master nodes. There is no parameter to control this. The only thing we can get from master server nodes is how many seconds it is behind the other master server.
The following parameter gives us the above value when we so "Show slave status" on any master mysql prompt : "Seconds_Behind_Master"
 (http://dev.mysql.com/doc/refman/5.7/en/show-slave-status.html)

Q: What Network topologies(Same Zone, Multiple Zones) are suggested?

A: .As mentioned in previous question, as long as we make sure the network latency between 2 master nodes is as much less as possible we can use any topology. There are no recommended practices on this in mysql documentation

Appendix

• What if I want to do a Manual Switch over from Master-1 to Master-2?
  • Put a 2 way replication as above and do not enable the db ha in db.properties. I.e put the value false against the following property in db.properties
    db.ha.enabled=false

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