I want to refer to two features within Kemp Loadmaster:
Drop Connections on Real Server (Exsist from 5.x) (Default not enabled!!).
Failure & Drop at Drain Time End (New feature at 7.04) (Default not Enabeld!!)
Drop Connections on Real Server Failure
By default existing connections are not closed if a Real Server fails. This can lead to issues with Outlook clients if an Exchange CAS server fails. A solution to this is to enable the Drop Connections on RS Failure option which can be found on the System Configuration > Miscellaneous > L7 Configuration screen in the WUI.
When this option is enabled, LoadMaster tracks all the incoming connections and which Real Servers they are connected to. When a Real Server fails, all connections to the Real Server are immediately dropped, forcing the connections to reconnect to a different Real Server.
Enabling this option has the added benefit of allowing relatively higher Idle Connection Timeout values to be set as the danger of the client retaining a connection to a failed server is removed.
Drop at Drain Time End
By default existing connections are not closed when a real server is disabled. This can lead to issues with Outlook clients if an Exchange CAS server is administratively disabled. A solution to this is to enable the Drop at Drain Time End option which can be found on the System Configuration > Miscellaneous > L7 Configuration screen in the WUI.
When this option is enabled, LoadMaster will sever all existing connections to a disabled server after the L7 Connection Drain Time is reached. Clients will then be fored to reestablish a connection to one of the remaining Real Servers.
