The behavior of dhcp failover when a dhcp server down

Issue

• The following DHCP's behaviors are correct?
  • The behavior of dhcp failover when a dhcp server down.
  • At the first, primary DHCP and secondary DHCP server have the same number of leases. e.g.(primary 50: secondary 50 )
  • When DHCP-failover happens (it means that primary DHCP down), we expected  DHCP's leases increase by primary's leases. e.g.(primary 0: secondary 100)
  • But, secondary DHCP's lease does not increase by failover and keeps the same number as it was before. e.g.(  primary 0: secondary 50)