High availability using full memory replication between virtual machine instances on a network device

摘要

Techniques are described for providing high availability for a network device, e.g., a router, using full memory replication between a primary virtual machine (VM) and a standby VM running on the network device. In one example, the techniques provide hot-standby high availability for a router by initializing a primary VM and a standby VM on the router at the same time. In another example, the techniques provide high availability for the router by initializing a standby VM on the router upon detecting a failure of the primary VM. In both examples, the primary VM controls the routing functionality and periodically stores a full memory state. Upon a failure of the primary VM, a hypervisor may perform a full memory replication between the primary VM and the standby VM. The standby VM may then take control of the routing functionality at the last stored state of the memory.

主权项

1. A method comprising:
executing a first virtual machine (VM) within an operating environment on a network device, wherein the first VM controls routing functionality of the network device; periodically storing a full memory state of the first VM, wherein the stored full memory state of the first VM comprises link states that comprise states of physical links between network devices in a network; upon detecting a failure of the first VM, replicating the stored full memory state of the first VM to a second VM executing within the operating environment on the network device, wherein replicating the stored full memory state comprises replicating the link states of the first VM to the second VM, and translating, with the second VM, the link states into kernel objects for a software system executed by the second VM; and switching control of the routing functionality from the first VM to the second VM.