Check that the Abiquo RabbitMQ queues are empty. The number of messages in all queues must be 0:

In a standard environment, the RabbitMQ service is on the Abiquo API server. Depending on the environment, this will be the Abiquo Monolithic or the Abiquo Server appliance.
Check for any active V2V conversions by checking for the V2V or Mechadora processes

Stop the API on the API server or monolithic server
Stop the UI on the API server or monolithic server or dedicated UI server
Stop remote services server
Stop the database on the monolithic server or database server.
For a datanode configuration, you will also need to stop the Galera cluster. For more details, see Stop and start HA configuration
Stop RabbitMQ (on the monolithic server or API server or Datanode)
V2V Server -
You do not need to stop anything because the BPM remote service is run on-demand only
Stop monitoring server
On the monitoring server, check if Cassandra is really dead
Get the process number for Cassandra (the first number in the output of the previous command), and kill it. In this example, Cassandra is process 12345.

Prepare to upgrade Abiquo