Replication method

• US 6,301,589 B1
• Filed: 12/02/1998
• Issued: 10/09/2001
• Est. Priority Date: 12/04/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kikuchi, Satoshi, Yui, Hitoshi, Hirashima, Yoko
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): Veillard, Jacques
• Application Number:
  US09/203,570
• Time in Patent Office: 1,042 Days
• Field of Search: 707/204, 707/201, 707/202, 707/203, 707/8, 707/104, 707/200, 709/217, 709/218, 709/203, 909/200, 909/201, 909/223, 379/34
• US Class Current: 1/1
• CPC Class Codes: H04L 61/4517 using open systems interconnection [OSI] directories, e.g. X.500
• CPC Class Codes: H04L 61/4523 using lightweight directory access protocol [LDAP]
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A directory system for performing replication of directory data, in which a directory server on the consumer side can reconstruct replica data using a backup kept at any point in time. Information 10c for specifying the entry changed for the last time by replication performed by replication service 10′ is recorded into the replica data 9c managed by the directory server on the consumer side. Based on this information, the replication service 10′ can know the entry on which next replication is to be performed. Thus, the replication service 10′ can recognize the difference between the master data 9s managed by the directory server on the supplier side and the replica data 9c, and can perform replication on this difference when only the replica data 9c is reconstructed using the backup.

Claims

1. A replication method for keeping contents of master data and contents of replica data identical to each other in a directory system, in which, a first directory server manages the master data of directory data and records and holds replication log of operations in changing said master data;

one or more second directory servers each manages its replica data as a replica of said master data; and

said first directory server and said one or more second directory servers are capable of being connected through a network;

wherein said replication method comprises;

said first directory server acquires a replication log which becomes an object of processing out of the replication log recorded and held by said first directory server, and issues a replication request that requests performing, on said replica data, the same operations as operations corresponding to the acquired replication log to said second directory server;

said first directory server and the second directory server record an identifying information for specifying the replication log corresponding to said operations performed by said second directory server when said operation performed in accordance with said replication request is successful; and

the identifying information recorded by said second directory server is referred to, so as to decide the replication log to be acquired, in acquiring the replication log which is to be a new object of processing from the replication log recorded and held by said first directory server.

2. The replication method according to claim 1, wherein said replication server issues a directory access request that requests performing an operation of searching said identifying information, to said second directory server, so as to refer to the identifying information recorded in the replica data managed by said second directory server.

3. The replication method according to claim 2, wherein:

said replication server issues a directory access request that requests performing an operation of recording said identifying information, to said second directory server, so as to record said identifying information into the replica data managed by said second directory server.

4. The replication method according to claim 3, wherein:

even when the operations performed by said second directory server in accordance with said replication request result in failure, said replication server judges the failure as success if the failure is caused by issuing the same replication request as the replication request successively more than once, and the second servers previously received the same replication request as the replication request.

5. The replication method according to claim 2, wherein:

said second directory server performs a predefined specific operation in accordance with contents set into a predefined specific field within a directory access request received; and

said replication server sets, into said specific field of said replication request, information necessary for said second directory server to perform a specific operation of recording said identifying information, so that said identifying information is recorded into the replica data managed by said second directory server.

6. The replication method according to claim 5, wherein:

said second directory server performs an operation according to said replication request and an operation of recording said identifying information, in the same single transaction.

7. The replication method according to claim 6, wherein:

said first directory server and said second directory server belong to one object class, and manage respectively entries constituting said master data and said replica data, as objects, each having one or more attributes; and

said identifying information belongs to a specific object class defined in advance, and recorded into an entry managed as an object having a specific attribute defined in advance, as an attribute value of said specific attribute.

8. A replication method for maintaining contents of master data and contents of replica data in a directory system, in which, a first directory server manages the master data of directory data and maintains replication log of operations in changing said master data;

a second directory server manages the replica data as a replica of said master data; and

said first directory server and said second directory server are capable of being connected through a network;

wherein said replication method comprises;

said first directory server acquiring a replication log that becomes an object of processing from the replication log maintained by said first directory server, and issues a replication request that requests performing, on said replica data, the same operations as operations corresponding to the acquired replication log to said second directory server;

said first directory server and the second directory server record an identifying information for specifying the replication log corresponding to said operations performed by said second directory server; and

the identifying information recorded by said second directory server is referred to in acquiring the replication log that is to be a new object of processing from the replication log recorded and held by said first directory server.

9. The replication method according to claim 8, wherein said replication server issues a directory access request that requests performing an operation of searching said identifying information, to said second directory server, so as to refer to the identifying information recorded in the replica data managed by said second directory server.

10. The replication method according to claim 9, wherein:

said replication server issues a directory access request that requests performing an operation of recording said identifying information, to said second directory server, so as to record said identifying information into the replica data managed by said second directory server.

11. The replication method according to claim 10, wherein:

even when the operations performed by said second directory server in accordance with said replication request result in failure, said replication server judges the failure as success if the failure is caused by issuing the same replication request as the replication request successively more than once, and the second servers previously received the same replication request as the replication request.

12. The replication method according to claim 9, wherein:

said second directory server performs a predefined specific operation in accordance with contents set into a predefined specific field within a directory access request received; and

said replication server sets, into said specific field of said replication request, information necessary for said second directory server to perform a specific operation of recording said identifying information, so that said identifying information is recorded into the replica data managed by said second directory server.

13. The replication method according to claim 12, wherein:

said second directory server performs an operation according to said replication request and an operation of recording said identifying information, in the same single transaction.

14. The replication method according to claim 13, wherein:

said first directory server and said second directory server belong to one object class, and manage respectively entries constituting said master data and said replica data, as objects, each having one or more attributes; and

said identifying information belongs to a specific object class defines in advance, and recorded into an entry managed as an object having a specific attribute defined in advance, as an attribute value of said specific attribute.