System and method for addition and removal of servers in server cluster

• US 9,344,569 B2
• Filed: 03/15/2013
• Issued: 05/17/2016
• Est. Priority Date: 12/04/2012
• Status: Active Grant

• Current Assignee: Genesys Telecommunications Laboratories Incorporated (Genesys Cloud Services Incorporated)
• Original Assignee: Genesys Telecommunications Laboratories Incorporated (Genesys Cloud Services Incorporated)
• Inventors: Kolesov, Victor, Glagolev, Anatoliy, Tikin, Alexander
• Primary Examiner(s): Tiv, Backhean
• Application Number:
  US13/844,159
• Publication Number:
  US 20140156789A1
• Time in Patent Office: 1,159 Days
• Field of Search: 709/217
• US Class Current: 1/1
• CPC Class Codes: G06F 40/205 Parsing
• CPC Class Codes: G06F 9/50 Allocation of resources, e.g. of the central processing unit [CPU]
• CPC Class Codes: G06Q 10/063114 Status monitoring or status determination for a person or group
• CPC Class Codes: H04L 41/04 Network management architectures or arrangements
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 45/26 Route discovery packet
• CPC Class Codes: H04L 61/106 across networks, e.g. mapping telephone numbers to data network addresses
• CPC Class Codes: H04L 61/4541 Directories for service discovery
• CPC Class Codes: H04L 61/4557 Directories for hybrid networks, e.g. including telephone numbers
• CPC Class Codes: H04L 65/1045 Proxies, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/401 wherein the services involve a main real-time session and one or more additional parallel real-time or time sensitive sessions, e.g. white board sharing or spawning of a subconference
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04M 2203/402 Agent or workforce management
• CPC Class Codes: H04M 3/42306 Number translation services, e.g. premium-rate, freephone or vanity number services
• CPC Class Codes: H04M 3/5191 interacting with the Internet
• CPC Class Codes: H04M 3/5232 Call distribution algorithms

Abstract

A method of adding a server to, or removing a server from, a cluster of servers, and of transferring state information. A new server being added sends a message to all existing servers indicating that it is being added, the new server sends a request for state information, the existing servers in the cluster transfer state information to the new server, and the new server sends a commit message to finalize its addition. Acknowledge messages are exchanged during the process. An existing server being removed sends, to the remaining servers, an initiate message, a transfer of state information, and a commit message to finalize the removal, with acknowledge messages exchanged during the process.

Claims

1. A method for adding a first server to a group of existing second servers associated with a contact center, the method comprising:

sending by the first server not already belonging to the group of existing second servers, a request for initiating addition of the first server to the group of existing second servers;

sending, by each of the plurality of existing second servers, in response to the request, state information for a resource mapped to the existing second server, the state information being transmitted to the first server without sending the state information to one of the existing second servers; and

sending, by the first server, a commit message to each of the existing servers, in response to receiving the state information from each of the plurality of existing second servers; and

changing the mapping of one of the resources from one of the existing second servers to the first server in response to the commit message.

2. The method of claim 1, comprising:

sending, by the first server, to each of the plurality of existing second servers, an initiate message;

sending, by each of the plurality of existing second servers, to the first server, an initiation acknowledge message; and

sending, by the first server, to each of the plurality of existing second servers, a state transfer request.

3. The method of claim 1, comprising:

notifying a configuration server, responsible for maintaining a list of servers, of the addition of the first server;

updating, by the configuration server, the list of servers; and

notifying, by the configuration server, a set of subscribers of the update to the list of servers.

4. The method of claim 1 further comprising:

receiving a request associated with a resource mapped to the first server from the existing second servers;

identifying the first server as responsible for the resource; and

routing the request to the first server in response to the identifying.

5. The method of claim 4, wherein the resource is a directory number (DN).

6. The method of claim 4, wherein the identifying of the first server as responsible for the resource comprises:

providing, to a function, a resource identifier (ID) identifying the resource; and

receiving as an output from the function a module identifier (ID) for the first server.

7. The method of claim 6, wherein the function is a hash function.

8. The method of claim 7, wherein the hash function is a consistent hash function.

9. The method of claim 8, wherein the hash function comprises:

a first basic hash function configured to map resource identifiers into a range; and

a second basic hash function configured to map module identifiers into the range.

10. The method of claim 9, wherein the second basic hash function is further configured to map a replica of each module identifier into the range.

11. The method of claim 7, wherein the hash function is configured to map resource identifiers corresponding to resources in a geographic region into module identifiers corresponding to servers executing on computing devices in the geographic region.

12. The method of claim 1 further comprising:

sending by the first server a request for initiating removal of the first server from the group of servers;

sending, by the first server, state information for a second resource mapped to the first server, the state information for the second resource being transmitted by the first server without state information being transmitted by one of the other second servers; and

sending, by the first server, a second commit message to each of the other second servers; and

changing the mapping of the second resource from the first server to one of the other second servers in response to the second commit message.

13. The method of claim 12, comprising:

sending, by each of the plurality of other second servers, to the first server, an initiation acknowledge message.

14. The method of claim 12, comprising:

notifying a configuration server, responsible for maintaining a list of servers, of the removal of the first server;

updating, by the configuration server, the list of servers; and

notifying, by the configuration server, a set of subscribers of the update to the list of servers.

15. The method of claim 12, further comprising:

receiving a request associated with the second resource mapped to a remaining server of the plurality of other second servers from the first server;

identifying the remaining server as responsible for the second resource; and

routing the request to the remaining server in response to the identifying.

16. The method of claim 15, wherein the identifying of the remaining server as responsible for the second resource comprises:

providing, to a function, a resource identifier (ID) identifying the second resource; and

receiving as an output from the function a module identifier (ID) for the remaining server.

17. The method of claim 16, wherein the function is a hash function.

18. The method of claim 17, wherein the hash function is a consistent hash function.

19. The method of claim 18, wherein the hash function comprises:

a first basic hash function configured to map resource identifiers into a range; and

a second basic hash function configured to map module identifiers into the range.

20. The method of claim 19, wherein the second basic hash function is further configured to map a replica of each module identifier into the range.

21. The method of claim 17, wherein the hash function is configured to map resource identifiers corresponding to resources in a geographic region into module identifiers corresponding to servers executing on computing devices in the geographic region.