Method and system for balancing network load in a virtual environment

A system for automatically balancing network load in a virtual environment, the system comprising:

• at least one computer running at least one hypervisor managing the virtual environment, the virtual environment comprising a plurality of virtual hosts and a plurality of virtual routers, the plurality of virtual hosts and the plurality of virtual routers running on at least one virtual machine within the virtual environment, wherein the system is configured to:
• establish a plurality of groups associated with the plurality of virtual routers, the plurality of groups comprising a first group and a second group, the plurality of virtual routers comprising a first virtual router and a second virtual router;
• assign the plurality of virtual hosts to the plurality of groups, wherein one of the plurality of virtual hosts is assigned to the first group and another one of the plurality of virtual hosts is assigned to the second group, wherein each of the plurality of virtual hosts comprises an ARP cache comprising a default gateway MAC address for routing network traffic from the plurality of virtual hosts;
• assign a plurality of priority values for the plurality of groups to the plurality of virtual routers, wherein one of the plurality of virtual routers having a highest priority value for a group in the plurality of groups is a master virtual router for the group, wherein the first virtual router has the highest priority value for the first group and the highest priority value for the second group;
• initialize an additional virtual router within the plurality of virtual routers when network traffic load exceeds a defined threshold, wherein the additional virtual router has the highest priority value for the second group;
• wherein each of the plurality of virtual routers is in either a master state or a backup state for at least one of the plurality of virtual routers;
• wherein each of the plurality of virtual routers is configured to periodically advertise a priority value to other virtual routers that are configured to receive advertised priority values, such that a backup virtual router for at least one group transitions to the master state for the at least one group if the priority value of the backup virtual router for the at least one group is greater than the priority value of the master virtual router for the at least one group, and the master virtual router for the at least one group transitions to a backup virtual router state for the at least one group if the priority value of the backup virtual router for the at least one group is greater than the priority value of the master virtual router for the at least one group;
• wherein the master virtual router for the at least one group in the plurality of groups periodically sends a gratuitous ARP packet to the plurality of virtual hosts assigned to the at least one group, and a sender hardware address of the gratuitous ARP packet is an updated gateway MAC address;
• and
• wherein each of the plurality of virtual hosts assigned to the at least one group updates its default gateway MAC address in the ARP cache based on the updated gateway MAC address.

A non-transitory computer-readable storage medium containing program instructions for automatically balancing network load in a virtual environment comprising a plurality of virtual hosts and a plurality of virtual routers, the plurality of virtual hosts and the plurality of virtual routers running on at least one virtual machine within the virtual environment, wherein execution of the program instructions by one or more processors of a computer system causes the one or more processors to perform steps comprising:

• establishing a plurality of groups associated with the plurality of virtual routers, the plurality of groups comprising a first group and a second group, the plurality of virtual routers comprising a first virtual router and a second virtual router;
• assigning the plurality of virtual hosts to the plurality of groups, wherein one of the plurality of virtual hosts is assigned to the first group and another one of the plurality of virtual hosts is assigned to the second group, wherein each of the plurality of virtual hosts comprises an ARP cache comprising a default gateway MAC address for routing network traffic from the plurality of virtual hosts;
• assigning a plurality of priority values for the plurality of groups to the plurality of virtual routers, wherein one of the plurality of virtual routers having a highest priority value for a group in the plurality of groups is a master virtual router for the group, wherein the first virtual router has the highest priority value for the first group and the highest priority value for the second group;
• initializing an additional virtual router within the plurality of virtual routers when network traffic load exceeds a defined threshold, wherein the additional virtual router has the highest priority value for the second group;
• wherein each of the plurality of virtual routers is in either a master state or a backup state for at least one of the plurality of virtual routers;
• wherein each of the plurality of virtual routers is configured to periodically advertise a priority value to other virtual routers that are configured to receive advertised priority values, such that a backup virtual router for at least one group transitions to the master state for the at least one group if the priority value of the backup virtual router for the at least one group is greater than the priority value of the master virtual router for the at least one group, and the master virtual router for the at least one group transitions to a backup virtual router state for the at least one group if the priority value of the backup virtual router for the at least one group is greater than the priority value of the master virtual router for the at least one group;
• wherein the master virtual router for the at least one group in the plurality of groups periodically sends a gratuitous ARP packet to the plurality of virtual hosts assigned to the at least one group, and a sender hardware address of the gratuitous ARP packet is an updated gateway MAC address;
• and
• wherein each of the plurality of virtual hosts assigned to the at least one group updates its default gateway MAC address in the ARP cache based on the updated gateway MAC address.