Abstract: The method includes modifying a routing rule of a load balancer of the system, the rule representing at least one parameter for communications between a client device and the first VM to specify that data from the client device destined for the first VM instance is queued, suspending processing, at the first VM instance, of pending requests from the client device, transmitting data, from the first VM instance, to the load balancer representing the state of the or each suspended request, modifying the routing rule to specify that the endpoint for a communication channel from the second VM instance is the client device, transmitting the or each suspended request to the second VM instance, and modifying the routing rule to specify transmission of data from the client device directly to the second VM instance.

Abstract: A method, in a virtualized system, for balancing a load across multiple virtual machines instantiated over physical hardware of the system, including vertically scaling the capacity of respective ones of the VMs up to a physical capacity limit, LPHY, from an initially allocated physical capacity, LVIRT, by providing access to additional resources of the physical hardware in response to an increased load causing the or each VM to reach or exceed a threshold capacity LT1, and horizontally scaling the capacity of the system by supplementing the multiple VMs with an additional VM instantiated using a hypervisor of the system when a predefined proportion, U1, of the VMs have a capacity LPHY.

Abstract: The method includes modifying a routing rule of a load balancer of the system, the rule representing at least one parameter for communications between a client device and the first VM to specify that data from the client device destined for the first VM instance is queued, suspending processing, at the first VM instance, of pending requests from the client device, transmitting data, from the first VM instance, to the load balancer representing the state of the or each suspended request, modifying the routing rule to specify that the endpoint for a communication channel from the second VM instance is the client device, transmitting the or each suspended request to the second VM instance, and modifying the routing rule to specify transmission of data from the client device directly to the second VM instance.

Abstract: A method, in a virtualised system, for balancing a load across multiple virtual machines instantiated over physical hardware of the system, including vertically scaling the capacity of respective ones of the VMs up to a physical capacity limit, LPHY, from an initially allocated physical capacity, LVIRT, by providing access to additional resources of the physical hardware in response to an increased load causing the or each VM to reach or exceed a threshold capacity LT1, and horizontally scaling the capacity of the system by supplementing the multiple VMs with an additional VM instantiated using a hypervisor of the system when a predefined proportion, U1, of the VMs have a capacity LPHY.