Load-balancing in replication engine of directory server

• US 8,832,215 B2
• Filed: 12/02/2009
• Issued: 09/09/2014
• Est. Priority Date: 12/02/2009
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Patel, Virag S.
• Primary Examiner(s): Whipple, Brian P
• Assistant Examiner(s): EDWARDS, JAMES A
• Application Number:
  US12/629,530
• Publication Number:
  US 20110131288A1
• Time in Patent Office: 1,742 Days
• Field of Search: 709/208
• US Class Current: 709/208
• CPC Class Codes: G06F 9/505 considering the load
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1019 Random or heuristic server selection
• CPC Class Codes: H04L 67/1036 Load balancing of requests to servers for services different from user content provisioning, e.g. load balancing across domain name servers

Abstract

An embodiment of this invention provides a new LDAP server control to automate load balancing for replication based directory infrastructure. This solution is applicable to both master-master and master-replica based replication topologies. If one or more of the replication servers or the master servers are available for processing, the request is assigned to them based on output of a weighted non-uniform random number generator. This LDAP server control allows gaining very high performance while doing multiple parallel heavy LDAP operations. This LDAP control prevents the exposure of the replication directory server details to the outer world and therefore proves helpful in easing the security concerns.

Claims

1. A computer product for automatic load-balancing in a plurality of directory servers comprising a master server and one or more replication servers, the computer product comprising a non-transitory computer readable medium, upon which is stored computer readable information that, upon being executed on one or more computers, causes steps comprising:

receiving a request for the plurality of directory servers, wherein the plurality of directory servers are Lightweight Directory Access Protocols (LDAP) servers and the request is an LDAP request;

identifying the received request to be a read request;

conducting a first availability check to determine whether the plurality of directory servers are available or busy;

determining, from the first availability check, that the one or more replication servers are busy; and

assigning the read request to the master server if the master server is determined to be available, or else conducting a second availability check if the master server is determined to be busy, wherein an automatic load-balancing policy seeks to assign the read request to an available one of the one or more replica servers, if any, before seeking to assign the read request to the master server.

2. The computer product of claim 1, further comprising:

adding the read request to a common queue prior to conducting the second availability check if the master server is determined to be busy.

3. The computer product of claim 2, further comprising:

assigning the read request to a first one to be identified as available among the master server and the one or more replication servers in response to the read request being added to the common queue.

4. The computer product of claim 1, wherein the master server is determined to be busy from the first availability check.

5. The computer product of claim 1, wherein the first availability check determines availability status of each of the plurality of directory servers.

6. The computer product of claim 1, further comprising:

determining whether the request is a read request or a write request.

7. The computer product of claim 6, further comprising:

in response to determining the request to be a read request, conducting the first availability check to determine availability status of each of the plurality of directory servers.

8. The computer product of claim 1, wherein the master server and the one or more replication servers are configured in a master-replica topology, the steps further comprising:

receiving a write request; and

assigning the write request to the master server.

9. A computer product for automatic load-balancing in a plurality of directory servers comprising a plurality of master servers and a plurality of replication servers, the computer product comprising a non-transitory computer readable medium, upon which is stored computer readable information that, upon being executed on one or more computers, causes steps comprising:

receiving a request for the plurality of directory servers, wherein the plurality of directory servers are Lightweight Directory Access Protocols (LDAP) servers and the request is an LDAP request;

identifying the received request to be a read request;

conducting a first availability check to determine whether the plurality of directory servers are available or busy;

determining, from the first availability check, that the plurality of replication servers are busy; and

assigning the read request to one of the plurality of master servers if at least one of the plurality of master servers is determined to be available, or else conducting a second availability check if all of the plurality of master servers are determined to be busy, wherein an automatic load-balancing policy seeks to assign the read request to an available one of the one or more replica servers, if any, before seeking to assign the read request to the master server.

10. The computer product of claim 9, further comprising:

adding the read request to a common queue prior to conducting the second availability check.

11. The computer product of claim 10, further comprising:

assigning the read request to a first one to be identified as available among the plurality of master servers and the plurality of replication servers in response to the read request being added to the common queue.

12. The computer product of claim 9, wherein the plurality of master servers are determined to be busy from the first availability check.

13. The computer product of claim 9, wherein the first availability check determines availability status of each of the plurality of directory servers.

14. The computer product of claim 9, further comprising:

determining whether the request is a read request or a write request.

15. The computer product of claim 14, further comprising:

in response to determining the request to be a read request, conducting the first availability check to determine availability status of each of the plurality of directory servers.

16. The computer product of claim 9, wherein at least one master server among the plurality if master servers and at least one replication server among the plurality of replication servers are configured in a master-replica topology, the steps further comprising:

receiving a write request; and

assigning the write request to one of the plurality of master servers.

17. A system configured for automatic load-balancing comprising:

a plurality of master servers among a plurality of directory servers;

a plurality of replication servers among the plurality of directory servers, wherein the plurality of directory servers are Lightweight Directory Access Protocols (LDAP) servers and the request is an LDAP request; and

means for load balancing configured to receive a read request for the plurality of directory servers, determine from a first availability check that the plurality of replication servers are busy, and assign the read request to one of the plurality of master servers if at least one of the plurality of master servers is determined to be available, or else conduct a second availability check if all of the plurality of master servers are determined to be busy, wherein an automatic load-balancing policy seeks to assign the read request to an available one of the one or more replica servers, if any, before seeking to assign the read request to the master server.

18. The system of claim 17, wherein the means for load balancing is further configured to add the read request to a common queue prior to conducting the second availability check, and assign the read request to a first one to be identified as available among the plurality of master servers and the plurality of replication servers in response to the read request being added to the common queue.

19. The system of claim 17, wherein the means for load balancing is further configured to conducting the first availability check to determine availability status of each of the plurality of directory servers in response to determining that a received request is the read request.

20. The system of claim 17, wherein upon a write request being received for the plurality of directory servers the means for load balancing is further configured to assign the write request to one of the plurality of master servers.