Techniques for replicating state information for high availability

A computer system, comprising:

• one or more processors and a non-transitory computer-readable storage medium of a first network virtualization device (NVD) of a physical network, the non-transitory computer-readable storage medium containing instructions which, when executed on the one or more processors, cause the one or more processors to perform operations including:
• receiving a first portion of first state information of a first virtual network interface card (VNIC) of a set of VNICs, wherein the first VNIC is hosted by a second NVD, wherein the first VNIC performs forwarding of packets for a set of one or more packet flows from a compute instance hosted on a physical host machine connectively coupled to the second NVD, wherein the first NVD is a backup for the first VNIC, wherein:
• the physical network hosts a virtual network, the physical network comprising the physical host machine, the first NVD, and the second NVD, and wherein the first NVD and the second NVD are different physical devices with separate processors from network interface cards of the physical host machine, and
• the virtual network comprises one or more compute instances including the compute instance, and the set of VNICs;
• storing the first portion of the first state information for the first VNIC;
• receiving availability information indicating that the second NVD is unavailable;
• receiving packets associated with the set of one or more packet flows;
• and
• forwarding the packets based on the first portion of the first state information.

One or more non-transitory computer-readable media storing instructions that, upon execution on a first network virtualization device (NVD) of a physical network, cause the first NVD to perform operations comprising:

• receiving a first portion of first state information of a first virtual network interface card (VNIC) of a set of VNICs, wherein the first VNIC is hosted by a second NVD, wherein the first VNIC performs forwarding of packets for a set of one or more packet flows from a compute instance hosted on a physical host machine connectively coupled to the second NVD, wherein the first NVD is a backup for the first VNIC, wherein:
• the physical network hosts a virtual network, the physical network comprising the physical host machine, the first NVD, and the second NVD, and wherein the first NVD and the second NVD are different physical devices with separate processors from network interface cards of the physical host machine, and
• the virtual network comprises one or more compute instances including the compute instance, and the set of VNICs;
• storing the first portion of the first state information for the first VNIC;
• receiving availability information indicating that the second NVD is unavailable;
• receiving packets associated with the set of one or more packet flows;
• and
• forwarding the packets based on the first portion of the first state information.