Hitless upgrade of a network device

A non-transitory computer-readable medium storing a set of instructions, the set of instructions comprising:

• one or more instructions that, when executed by one or more processors of a network device, cause the network device to:
• determine that a control plane of the network device is to be rebooted as part of performance of an in-service software upgrade (IS SU) procedure;
• cause, based on determining that the network device is to be rebooted, a plurality of applications of the network device to stop executing on the network device;
• cause, based on causing the plurality of applications to stop executing, a control plane state of the network device to be frozen,
• wherein the one more instructions, that cause the network device to cause the control plane state of the network device to be frozen, cause the network device to:
• identify data objects that are associated with the control plane state and that are stored in one or more distributed data structures, and
• cause the data objects to be stored in a non-distributed data structure to preserve the data objects during performance of the ISSU procedure;
• cause, after causing the control plane state of the network device to be frozen, the ISSU procedure to be performed;
• and
• cause, based on causing the ISSU procedure to be performed, the data objects to be restored in the one or more distributed data structures.

A method, comprising:

• causing, by a network device, a plurality of applications of the network device to stop executing on the network device;
• causing, by the network device and based on causing the plurality of applications to stop executing, a control plane state of the network device to be frozen,
• wherein causing the control plane state of the network device to be frozen includes:
• identifying, by the network device, data objects that are associated with the control plane state and that are stored in one or more distributed data structures, and
• causing, by the network device, the data objects to be stored in a non-distributed data structure to preserve the data objects during performance of an in-service software upgrade (ISSU) procedure;
• causing, by the network device and based on causing the control plane state of the network device to be frozen, the ISSU procedure to be performed;
• and
• causing, by the network device and based on causing the ISSU procedure to be performed, the data objects to be restored in the one or more distributed data structures.