Master device for controlling application security environments

A method implemented in a first apparatus implemented in hardware for controlling users in a first plurality of second apparatuses, wherein configuration of at least a first user of said first plurality of second apparatuses is to be stored in a second plurality of third apparatuses if said first user is created, said method comprising:

• a) sending a first command to each apparatus in said second plurality of third apparatuses to create said first user;
• b) receiving either a first synchronisation message or a first negative acknowledgement for said first command from each apparatus in said second plurality of third apparatuses;
• c) sending a second command to each apparatus in said second plurality of third apparatuses to discard said first command to create said first user if said first negative acknowledgement is received from at least one apparatus in said second plurality of third apparatuses, wherein each apparatus in said second plurality of third apparatuses discards said first command to create said first user when said second command is received;
• and
• d) sending a third command to each apparatus in said second plurality of third apparatuses to complete operation specified in said first command to create said first user if said first synchronisation message is received from each apparatus in said second plurality of third apparatuses, wherein each apparatus in said second plurality of third apparatuses updates said configuration to create said first user when said third command is received.