NimbostratusWhat happens to the existing connections to a pool node when a health monitor marks a pool node as unavailable? Do the connections get immediately dropped or does the LTM have the same behavior as if you forced the node offline?
CumulonimbusThe outcome of a health monitor will only aid the selection of a pool member for a new connection. When a health monitor fails, an existing connection should also fail if your monitor accurately reflects the health of the service, except in cases in which the pool member will not accept any new connections but will keep serving existing connections.
CirrusFor your specific use case, I would look into using the Receive Disable String on your health monitor. With this, you can query a specific file on your server with the monitor that can be changed by administrators or whomever. When it is changed to match the receive disable string, the server will be disabled which will not terminate any current connections but prevent any new ones. This will allow connections to slowly bleed off, changes to be made, and then the file can be changed to the receive string to mark the server as up again.
If you have any more questions, I am sure I can help.