Apparatus and methods for highly available directory services in the distributed computing environment

• US 6,014,686 A
• Filed: 06/20/1997
• Issued: 01/11/2000
• Est. Priority Date: 06/21/1996
• Status: Expired due to Term

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Inventors: Segal, Mark Edward, Ratan, Vivek, Elnozahy, Elmootazbellah Nabil
• Primary Examiner(s): Asta, Frank J.
• Assistant Examiner(s): YUAN, ALMARI ROMERO
• Application Number:
  US08/880,094
• Time in Patent Office: 935 Days
• Field of Search: 709/202, 709/211, 709/217, 709/218, 709/219, 709/224, 709/226, 709/227, 709/229, 709/234, 709/237, 709/239
• US Class Current: 709/202
• CPC Class Codes: G06F 11/1482 by means of middleware or OS functionality
• CPC Class Codes: G06F 11/2028 eliminating a faulty processor or activating a spare
• CPC Class Codes: G06F 11/2041 with more than one idle spare processing component
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548
• CPC Class Codes: G06F 9/547 Remote procedure calls [RPC]; Web services

Abstract

In the Distributed Computing Environment (DCE) standard, availability of directory services is increased by apparatus and methods using agents inserted between requesting clients and servers. By using agents, additional functions are carried out which are not performed in a typical DCE environment. Each agent inserts itself between the requesters and servers by writing over the pointer to the server with information pointing to the agent, thus redirecting requests to themselves. The agent then receives incoming requests and forwards them on to its associated server and other agents. The agent handling requests for the master server is called the "master" agent and the agents handling requests for replica servers are "replica" agents. The agents make sure requests are performed before replying to the original requester. Agents also monitor themselves. If a master agent crashes, the remaining agents elect a new master agent. If a replica agent crashes the master agent excludes the agent from further communications. The apparatus and methods provide a highly available and robust directory server.

Claims

1. Apparatus for a Distributed Computing Environment (DCE) including a first and at least one second Cell Directory Service (CDS) machine and a DCE client machine, including a CDS clerk for communicating with said first CDS machine, said apparatus providing automatic failover to said second machine on failure of said first machine and said apparatus comprising

a first CDS name server in said first CDS machine and a second CDS name server in each said second CDS machine,

a first agent in said first CDS machine distinct from and not a part of said first CDS name server but connected to said first CDS name server and to said CDS clerk in said DCE client machine, and

a second agent in said second CDS machine distinct from and not a part of said second CDS name server but connected to said second CDS name server and to said first agent, said first agent intercepting requests to said first CDS machine from said CDS clerk in said DCE client machine and forwarding the requests to said second agent.

2. The apparatus in accordance with claim 1 further comprising a security service connected to said first agent for determining that said CDS clerk in said DEC client machine is authorized to request changes in said first CDS name server.

3. A method for providing automatic failover from a first Cell Directory Service (CDS) machine acting as a master to a second CDS machine to act as a master in a Distributed Computing Environment (DCE), said first CDS machine including a first CDS name server and a first agent distinct from and not a part of said first CDS name server but connected thereto and said second CDS machine including a second CDS name server and a second agent distinct from and not a part of said second CDS name server but connected thereto, said method comprising the steps of

forwarding from a DCE client machine to said first CDS name server a request to update a name,

intercepting said request at said first agent and forwarding said request from said first agent to said first CDS name server to update its clearinghouse and to said second agent,

said second agent forwarding said request to said second CDS name server to update its clearinghouse,

said second agent monitoring the state of said first CDS machine, and

said second CDS machine becoming the master upon detection by said monitoring step of a failure of said first CDS machine.

4. The method in accordance with claim 3 further comprising the step of said second agent causing said second CDS name server to broadcast to the DCE client machine that said second CDS machine is then the master.

5. A method for providing automatic failover from a first Cell Directory Service (CDS) machine having a server and a first agent distinct from said first CDS server but connected thereto, said first agent acting as a master in a Distributed Computing Environment (DCE), to one of a plurality of second CDS machines each having a server and a second agent distinct from a second CDS server but connected thereto, each said second agent capable of acting as a master in the Distributed Computing Environment on failure of said first machine, said method comprising the steps of

monitoring by one of said second agents of one of said second CDS machines the state of said first agent of said first CDS machine, and

electing one of said second machines as a new master upon detection by said monitoring step of a failure in said first CDS machine.

6. The method in accordance with claim 5 further comprising said second agent of said new master machine causing the broadcasting that said second agent of said new master machine has replaced said first agent for receipt of requests in the DCE environment.