The official upgrade PDF instructions provide sample contents for the upgrade_config file (pasted below) in order to perform a silent upgrade. Does this sample contain all the necessary properties, or are there more that are needed but undocumented in order to ensure that the upgrade is truly "silent"? (note: my Cassandra and Zookeeper components are installed on the same servers)
IP1=xxxx
IP2=xxxx
IP3=xxxx
APIGEE_ADMINPW=xxxx
APIGEE_LDAPPW=xxxx
CASS_HOSTS="$IP1 $IP2 $IP3"
CASS_USERNAME=xxxx
CASS_PASSWORD=xxxx
MSNUM=1
Yes, those are the variables you will need for an upgrade. If you have more than one DC with Management Servers you will need one response file per DC.
On DC 1, the response file must contain: MSNUM=1
On DC 2, MSNUM=2
And so on.