High availability in-service software upgrade using virtual machine instances in dual computing appliances

• US 8,943,489 B1
• Filed: 06/29/2012
• Issued: 01/27/2015
• Est. Priority Date: 06/29/2012
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Qu, Hui
• Primary Examiner(s): Dao, Thuy
• Assistant Examiner(s): Wang, Ben C
• Application Number:
  US13/537,760
• Time in Patent Office: 942 Days
• Field of Search: None
• US Class Current: 717/168
• CPC Class Codes: G06F 8/656 while running
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors

Abstract

Techniques are described for providing high availability during an in-service software upgrade (ISSU) of an appliance within a network device, e.g., a router, by running a pair of virtual machines on each of a primary appliance and a secondary appliance within the router. Examples of the appliances include a routing engine within a router, and a service physical interface card (PIC) within a forwarding engine of a router. An ISSU of the primary appliance may first upgrade the operating system instance of a secondary virtual machine, switch operation from a primary virtual machine to the secondary virtual machine, and then upgrade the operating system instance on the primary virtual machine. During the ISSU of the primary appliance, primary and secondary virtual machines on the secondary appliance provide high availability to the virtual machine on the primary appliance executing the original operating system.

Claims

1. A method comprising:

running a first primary virtual machine (VM) on a primary appliance of a network device, wherein the first primary VM executes a first operating system that controls functionality of the primary appliance;

running a second primary VM on a secondary appliance of the network device, wherein the second primary VM on the secondary appliance executes the first operating system and provides high availability for the primary appliance;

in response to receiving an in-service software upgrade (ISSU) request, initializing a first secondary VM on the primary appliance and a second secondary VM on the secondary appliance, wherein each of the first secondary VM and the second secondary VM execute the first operating system;

performing the ISSU on the primary appliance by upgrading the first secondary VM on the primary appliance to a second operating system, switching control of the primary appliance from the first primary VM to the first secondary VM, and upgrading the first primary VM to the second operating system, wherein, during the ISSU of the primary appliance when the first primary VM and the first secondary VM on the primary appliance are executing different operating systems, the second primary VM executing the first operating system on the secondary appliance provides high availability for the primary appliance; and

if the first primary VM on the primary appliance fails during the ISSU of the primary appliance when the first primary VM and the first secondary VM on the primary appliance are executing different operating systems, switching control of the functionality of the primary appliance from the first primary VM on the primary appliance to the second primary VM on the secondary appliance, wherein the second secondary VM on the secondary appliance provides high availability for the secondary appliance.

2. The method of claim 1, wherein the primary appliance comprises a primary routing engine that controls routing functionality for the network device, and wherein the secondary appliance comprises a secondary routing engine that provides high availability for the primary routing engine.

3. The method of claim 1, wherein the primary appliance comprises a primary service physical interface card (PIC) that performs network services on packets received by the network device, and wherein the secondary appliance comprises a secondary service PIC that provides high availability for the primary service PIC.

4. The method of claim 3, further comprising managing the virtual machines on the primary service PIC and the secondary service PIC using a virtual machine manager executing on a control unit of the network device.

5. The method of claim 3, further comprising managing the virtual machines on the primary service PIC using a first virtual machine manager executing on the primary service PIC, and managing the virtual machines on the secondary service PIC using a second virtual machine manager executing on the secondary service PIC.

6. The method of claim 3, wherein the network services performed by the primary service PIC comprise one or more of firewall services and packet processing services including intrusion detection and prevention (IDP), packet flow monitoring, and authentication services.

7. The method of claim 1, wherein upgrading the first secondary VM on the primary appliance comprises:

installing the second operating system on the first secondary VM;

rebooting the first secondary VM; and

synchronizing the first secondary VM with the first primary VM on the primary appliance by replicating state information from the first primary VM onto the first secondary VM via a shared storage between the first primary VM and the first secondary VM on the primary appliance.

8. The method of claim 1, wherein, when the ISSU on the primary appliance is complete, the first primary VM executing the second operating system on the primary appliance provides high availability for the primary appliance.

9. The method of claim 1, further comprising, when the ISSU of the primary appliance is complete, performing the ISSU on the secondary appliance by upgrading the second secondary VM to the second operating system, switching control of the secondary appliance from the second primary VM to the second secondary VM, and upgrading the second primary VM to the second operating system.

10. The method of claim 9, wherein upgrading the second secondary VM on the secondary appliance comprises:

installing the second operating system on the second secondary VM;

rebooting the second secondary VM; and

synchronizing the second secondary VM with the second primary VM on the secondary appliance by replicating state information from the second primary VM onto the second secondary VM via a shared storage between the second primary VM and the second secondary VM on the secondary appliance, wherein the second primary VM synchronizes with the first secondary VM on the primary appliance.

11. The method of claim 9, wherein, when the ISSU of the secondary appliance is complete, the second primary VM on the secondary appliance provides high availability for the secondary appliance.

12. The method of claim 9, further comprising, when the ISSU of the secondary appliance is complete, terminating the first primary VM on the primary appliance and terminating the second primary VM on the secondary appliance.

13. The method of claim 1,

wherein the first primary VM on the primary appliance comprises a master VM and the first secondary VM on the primary appliance comprises a backup VM that synchronizes with the first primary VM,

wherein the second primary VM on the secondary appliance comprises a backup VM that synchronizes with the first primary VM on the primary appliance, and

wherein the second primary VM on the secondary appliance also comprises a master VM of the secondary appliance and the second secondary VM on the secondary appliance comprises a backup VM that synchronizes with the second primary VM.

14. A network device comprising one or more processors configured to operate as:

a primary appliance;

a secondary appliance;

a first hypervisor that runs one or more virtual machines on the primary appliance;

a second hypervisor that runs one or more virtual machines on the secondary appliance;

a first primary virtual machine (VM) running on the primary appliance, wherein the first primary VM is configured to execute a first operating system that controls functionality of the primary appliance; and

a second primary VM running on the secondary appliance, wherein the second primary VM is configured to execute the first operating system and provide high availability for the primary appliance,

wherein, in response to receiving an in-service software upgrade (ISSU) request, the first hypervisor initializes a first secondary VM on the primary appliance and the second hypervisor initializes a second secondary VM on the secondary appliance, wherein each of the first secondary VM and the second secondary VM execute the first operating system,

wherein the first hypervisor performs the ISSU on the primary appliance to upgrade the first secondary VM to a second operating system, switch control of the primary appliance from the first primary VM to the first secondary VM, and upgrade the first primary VM to the second operating system, wherein, during the ISSU of the primary appliance when the first primary VM and the first secondary VM on the primary appliance are executing different operating systems, the second primary VM executing the first operating system on the secondary appliance provides high availability for the primary appliance, and

wherein, if the first primary VM on the primary appliance fails during the ISSU of the primary appliance when the first primary VM and the first secondary VM on the primary appliance are executing different operating systems, the first and second hypervisors switch control of the functionality of the primary appliance from the first primary VM on the primary appliance to the second primary VM on the secondary appliance, wherein the second secondary VM on the secondary appliance provides high availability for the secondary appliance.

15. The network device of claim 14, wherein the primary appliance comprises a primary routing engine that controls routing functionality for the network device, and wherein the secondary appliance comprises a secondary routing engine that provides high availability for the primary routing engine.

16. The network device of claim 14, wherein the primary appliance comprises a primary service physical interface card (PIC) that performs network services on packets received by the network device, and wherein the secondary appliance comprises a secondary service PIC that provides high availability for the primary service PIC.

17. The network device of claim 16, wherein the processors are configured to operate as a control unit of the network device executing a virtual machine manager configured to manage the virtual machines on the primary service PIC and the secondary service PIC.

18. The network device of claim 16,

wherein the primary service PIC executes a first virtual machine manager configured to manage the virtual machines on the primary service PIC, and

wherein the secondary service PIC executes a second virtual machine manager configured to manage the virtual machines on the secondary service PIC.

19. The network device of claim 16, wherein the network services performed by the primary service PIC comprise one or more of firewall services and packet processing services including intrusion detection and prevention (IDP), packet flow monitoring, and authentication services.

20. The network device of claim 14, wherein the first hypervisor upgrades the first secondary VM on the primary appliance by:

installing the second operating system on the first secondary VM;

rebooting the first secondary VM; and

synchronizing the first secondary VM with the first primary VM on the primary appliance by replicating state information from the first primary VM onto the first secondary VM via a shared storage between the first primary VM and the first secondary VM on the primary appliance.

21. The network device of claim 14, wherein, when the ISSU of the primary appliance is complete, the first primary VM executing the second operating system on the primary appliance provides high availability for the primary appliance.

22. The network device of claim 14, wherein, when the ISSU on the primary appliance is complete, the second hypervisor performs the ISSU on the secondary appliance to upgrade the second secondary VM to the second operating system, switch control of the secondary appliance from the second primary VM to the second secondary VM, and upgrade the second primary VM to the second operating system.

23. The network device of claim 22, wherein the second hypervisor upgrades the second secondary VM on the secondary appliance by:

installing the second operating system on the second secondary VM;

rebooting the second secondary VM; and

synchronizing the second secondary VM with the second primary VM on the secondary appliance by replicating state information from the second primary VM onto the second secondary VM via a shared storage between the second primary VM and the second secondary VM on the secondary appliance, wherein the second primary VM synchronizes with the first secondary VM on the primary appliance.

24. The network device of claim 22, wherein, when the ISSU of the secondary appliance is complete, the second secondary VM on the secondary appliance provides high availability for the secondary appliance.

25. The network device of claim 22, wherein, when the ISSU of the secondary appliance is complete, the first hypervisor terminates the first primary VM on the primary appliance, and the second hypervisor terminates the second primary VM on the secondary appliance.

26. The network device of claim 14,

wherein the first primary VM on the primary appliance comprises a master VM and the first secondary VM on the primary appliance comprises a backup VM that synchronizes with the first primary VM,

wherein the second primary VM on the secondary appliance comprises a backup VM that synchronizes with the first primary VM on the primary appliance, and

wherein the second primary VM on the secondary appliance also comprises a master VM of the secondary appliance and the second secondary VM on the secondary appliance comprises a backup VM that synchronizes with the second primary VM.

27. A non-transitory, computer-readable storage medium comprising instructions that cause one or more programmable processors to:

run a first primary virtual machine (VM) on a primary appliance of a network device, wherein the first primary VM executes a first operating system that controls functionality of the primary appliance;

run a second primary VM on a secondary appliance of the network device, wherein the second primary VM on the secondary appliance executes the first operating system and provides high availability for the primary appliance;

in response to receiving an in-service software upgrade (ISSU) request, initialize a first secondary VM on the primary appliance and a second secondary VM on the secondary appliance, wherein each of the first secondary VM and the second secondary VM execute the first operating system;

perform the ISSU on the primary appliance by upgrading the first secondary VM on the primary appliance to a second operating system, switch control of the primary appliance from the first primary VM to the first secondary VM, and upgrade the first primary VM to the second operating system, wherein, during the ISSU of the primary appliance when the first primary VM and the first secondary VM on the primary appliance are executing different operating systems, the second primary VM executing the first operating system on the secondary appliance provides high availability for the primary appliance; and

if the first primary VM on the primary appliance fails during the ISSU of the primary appliance when the first primary VM and the first secondary VM on the primary appliance are executing different operating systems, switch control of the functionality of the primary appliance from the first primary VM on the primary appliance to the second primary VM on the secondary appliance, wherein the second secondary VM on the secondary appliance provides high availability for the secondary appliance.