Application based active-active data center network using route health injection and IGP

• US 20060195607A1
• Filed: 02/25/2005
• Published: 08/31/2006
• Est. Priority Date: 02/25/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Naseh, Zeeshan, Gundi, Vinay
• Granted Patent: US 7,769,886 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1006 with static server selection, e.g. the same server being selected for a specific client
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30

Abstract

A distributed data center topology having at least a pair of active data centers that can recover from a disaster at one of the data centers and achieves load balancing using IGP (Interior Gateway Protocol) between data centers. The distributed data centers use virtual IP addresses, route health injection and Border Gateway Protocol (BGP) for business continuance, disaster recovery and load balancing. Active applications are deployed at each data center to provide a logical active/standby configuration for certain applications. Alternatively, active applications are deployed at both sites and BGP routes traffic to the closest data center edge router. Load balancing occurs over an internal IGP link between sites.

Claims

1. A data center topology coupled to the internet comprising:

Two active data centers each coupled to the internet an internet service provider and at least one of said data centers coupled to a second internet service provider, each data center having an edge router broadcasting a common IP address and directly linked to the other data center;

each of said edge routers having a multilayer switch feature card (MSFC);

each edge router configured to redistribute route health injection (RHI) routes into OSPF and to summarize a host route on said MSFC;

each edge router further adapted to distribute OSPF into their BGP process using a prefix-list and to update neighboring routers with said routes; and

Means for implementing application-based load balancing between said data centers.

2. The data center topology of claim 1 wherein each data center is logically partitioned into an active and a standby site.

3. The data center topology of claim 1 further comprising means for detecting a disaster at one of said data centers by detecting a route being removed from a routing table.

4. The data center topology of claim 1 wherein said link between data centers comprises an IGP link.

5. The data center topology of claim 4 wherein each data center further comprises said edge router coupled by an internal network to a router and content switching module, said content switching module and said router sharing a common chassis for supporting virtual IP addresses.

6. The data center topology of claim 5 further comprising the step using the same virtual IP address (VIP) to represent the server cluster at each data center for each application.

7. The data center topology of claim 1 further comprising means for translating private virtual IP addresses to a public IP address.

8. In an autonomous system comprising at least two data centers, a method for load balancing and recovering from a disaster comprising the steps of:

hosting active applications and serving clients from said at least two active data centers in said autonomous system;

Configuring route summarization in BGP;

Configuring BGP route redistribution and route preference to update neighboring routers; and

Using application-based load balancing on a direct link between said at least two active data centers.

9. The method of claim 8 further comprising the step of using Exterior Border Gateway Protocol (E-BGP) for interautonomous system routing and to exchange network routing information with other networks.

10. The method of claim 9 further comprising the step of controlling incoming and outgoing routes in BGP by the using weights.

11. The method of claim 9 further comprising the step of probing the health of the servers in each data center and application daemons that run on the servers.

12. A data center system coupled to the internet comprising:

At least two active data centers each coupled to the internet by an edge router, each edge router broadcasting a common IP address and each edge router configured to;

redistribute route health injection (RHI) routes into OSPF;

summarizing a host route; and

distribute routes from OSPF into the BGP process of each edge router using a prefix-list to update neighboring routers with said routes; and

an IGP link for coupling said at least two data centers.

13. The data center system of claim 12 wherein one of said at least two data centers may change its active status by an IGP cost modification.

14. The data center system of claim 12 wherein each data center comprises a server farm having a plurality servers and computer resources coupled to said edge routers by a router and a load balancer.

15. The data center system of claim 14 wherein said servers use RHI to inject static host routes of interest to said router if said server farm is in an operational state.

16. The data center system of claim 15 wherein said router redistributes said static host route into its OSPF routing protocol and advertises said route to said edge router.

17. The data center system of claim 16 wherein said edge routers use an IP Anycast mechanism to load balance client requests.

18. The data center system of claim 14 wherein said router is coupled to said edge router by an IGP link.

19. The data center system of claim 12 wherein each of said edge routers is linked to a multilayer switch feature card.

20. The data center system of claim 13 wherein each of said edge routers couples said data center to a first internet service provider and one of said edge routers links a corresponding data center to a second internet service provider, wherein said one of said edge routers configures a first metric for the route updates sent to a router at said first internet service provider and a second metric for the route updates sent a router at said second internet service provider such that said first internet service provider is configured to be the preferred path to said at least one data center.

21. The data center system of claim 20 wherein inbound routes to said at least one data center are set so that said edge router selects said first internet service provider as a next-hop router.