REDUCING VIRTUAL IP-ADDRESS (VIP) FAILURE DETECTION TIME

• US 20130332597A1
• Filed: 06/11/2012
• Published: 12/12/2013
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Kumar, Mahesh
• Granted Patent: US 9,363,313 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 41/0896 Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 41/0897 by horizontal or vertical scaling of resources, or by migrating entities, e.g. virtual resources or entities
• CPC Class Codes: H04L 41/40 using virtualisation of network functions or resources, e.g. SDN or NFV entities
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer

Abstract

Methods and systems are provided for global server load balancing in a communication network using a global site selector and an application control engine in communication with the global site selector, in which the application control engine notifies the global site selector in response to a state change for a virtual internet protocol (VIP) address. Keepalive methods generally rely on periodically polling VIP addresses to check whether they are in an ONLINE or OFFLINE state. A minimum interval between two keepalives can be as long as 40 seconds, during which, without a mechanism to reflect state change to the load balancer in real time, if a VIP address changes state (e.g., VIP address failure), a customer can experience network outage during the time interval. Embodiments provide a mechanism to reflect, in real time, the current VIP address state to a global server load balancer to reduce failure detection time.

Claims

1. A system comprising:

a global site selector; and

an application control engine in communication with the global site selector, wherein;

the application control engine notifies the global site selector in response to a state change for a virtual internet protocol (VIP) address.

2. The system of claim 1, wherein:

the application control engine notifies the global site selector in response to a VIP address state changing from ONLINE to OFFLINE.

3. The system of claim 1, wherein:

the global site selector includes a keepalive engine; and

the application control engine notifies the keepalive engine of the state change of the VIP address.

4. The system of claim 1, wherein:

the global site selector includes a keepalive engine;

the keepalive engine periodically pings the application control engine regarding the state of the VIP address; and

the application control engine notifies the keepalive engine regarding a VIP address state change independently of answering pings regarding the state of the VIP address.

5. The system of claim 1, wherein the global site selector:

processes a domain name system (DNS) request;

performs a keepalive method configured to find a site with a VIP address in an ONLINE state; and

returns the VIP address for the site in response to the request.

6. The system of claim 1, wherein the application control engine:

hosts a plurality of VIP addresses, wherein;

the application control engine keeps track of a state of each VIP address, wherein;

a set of possible states of each VIP address includes an ONLINE state and an OFFLINE state.

7. The system of claim 1, wherein the global site selector includes a keepalive engine to:

periodically poll one or more VIP addresses hosted on the application control engine to check whether each VIP address is in an ONLINE state or an OFFLINE state; and

receive information in response to a state change of one of the VIP addresses, in addition to a polling response that indicates only the ONLINE state or the OFFLINE state, and in less than a minimum interval between the periodic polls.

8. A method comprising:

performing global server load balancing according to availability of a virtual internet protocol (VIP) address, wherein availability is indicated by a VIP address state; and

modifying the global server load balancing in response to a state change for the VIP address.

9. The method of claim 8, wherein modifying the global server load balancing in response to a state change for the VIP address further comprises:

in response to the VIP address state changing from ONLINE to OFFLINE, redirecting network traffic away from the VIP address.

10. The method of claim 8, further comprising:

periodically polling the VIP address and in response to the state of the VIP address being ONLINE, using the VIP address for load balancing; and

periodically polling the VIP address and in response to the state being OFFLINE, directing network traffic away from the VIP address.

11. The method of claim 8, further comprising:

periodically polling the VIP address and in response to the state being OFFLINE, directing network traffic away from the VIP address; and

responding, independently of the periodic polling, to the VIP address state changing from ONLINE to OFFLINE and, in response to the state change, directing network traffic away from the VIP address.

12. The method of claim 8, further comprising:

processing a domain name system (DNS) request;

performing a keepalive method configured to find a site with a VIP address in an ONLINE state, and

returning the VIP address for the site in response to the request.

13. The method of claim 8, further comprising:

hosting a plurality of VIP addresses including;

keeping track of a state of each VIP address, wherein

a set of possible states of each VIP address includes an ONLINE state and an OFFLINE state.

14. The method of claim 8, further comprising:

periodically polling one or more hosted VIP addresses to check whether each VIP address is in an ONLINE state or an OFFLINE state;

modifying the global server load balancing in response to a state change of one of the VIP addresses, in addition to a polling response that indicates only the ONLINE state or the OFFLINE state; and

responding to the state change in less than a minimum interval between the periodic polls.

15. A computer program product comprising a non-transitory computer readable medium having computer readable and executable code for instructing a processor to perform a method, the method comprising:

performing global server load balancing based on availability of a virtual internet protocol (VIP) address, wherein availability is indicated by a VIP address state; and

modifying the global server load balancing in response to a state change for the VIP address.

16. The computer program product of claim 15, wherein modifying the global server load balancing in response to a state change for the VIP address further comprises:

in response to the VIP address state changing from ONLINE to OFFLINE, redirecting network traffic away from the VIP address.

17. The computer program product of claim 15, wherein the method further comprises:

periodically polling the VIP address and, in response to the state being OFFLINE, directing network traffic away from the VIP address; and

responding, independently of the periodic polling, to the VIP address state changing from ONLINE to OFFLINE and, in response to the state change, directing network traffic away from the VIP address.

18. The computer program product of claim 15, wherein the method further comprises:

processing a domain name system (DNS) request;

performing a keepalive method configured to find a site with a VIP address in an ONLINE state, and

returning the VIP address for the site in response to the request.

19. The computer program product of claim 15, wherein the method further comprises:

hosting a plurality of VIP addresses including;

keeping track of a state of each VIP address, wherein

a set of possible states of each VIP address includes an ONLINE state and an OFFLINE state.

20. The computer program product of claim 15 wherein the method further comprises:

periodically polling one or more hosted VIP addresses to check whether each VIP address is in an ONLINE state or an OFFLINE state;

modifying the global server load balancing in response to a state change of one of the VIP addresses, in addition to a polling response that indicates only the ONLINE state or the OFFLINE state; and

responding to the state change in less than a minimum interval between the periodic polls.