Network management system and network management method capable of controlling agent even in case of fault occurring on logical communication channel

A network management method for controlling a network having a plurality of agents and a manager for controlling management objects of the plurality of agents which are respectively connected by a logical communication channel, the network management method comprising the steps of:

• in said manager,
• monitoring communication state between the plurality of agents and said manager itself;
• inquiring of said other agents whether communication with an agent incapable of communication is possible or not, when the manager fails to communicate with said agent;
• upon receipt of replies from acting manager candidates, that are agents capable of communicating with said agent incapable of communication, deciding one of said acting manager candidates as an acting manager;
• and
• controlling said management objects of said agent incapable of communication with said manager, through the mediation of said acting manager, while
• in each of said agents,
• checking whether the communication with said agent incapable of communication is possible or not, in reply to the inquiry from said manager;
• when the communication with said agent incapable of communication is possible, making a reply indicating that this agent is an acting manager candidate, for said manager;
• and
• receiving said management objects of said agent incapable of communication and sending said management objects to said manager.

A computer readable memory storing a computer program for controlling a network management system for controlling a network having a plurality of agents and a manager for controlling management objects of the plurality of agents which are respectively connected by a logical communication channel, wherein

• the computer program for controlling the manager comprising the steps of:
• monitoring the communication state between the plurality of agents and said manager itself;
• when the manager fails to communicate with said agent, inquiring of the other agents whether communication with an agent incapable of communication is possible or not;
• upon receipt of replies from acting manager candidates, that are agents capable of communication with said agent incapable of communication, deciding one of said acting manager candidates as an acting manager;
• and
• controlling said management objects of said agent incapable of communication with said manager, through the mediation of said acting manager, while
• the computer program for controlling the agents comprising the steps of:
• checking whether the communication with said agent incapable of communication is possible or not, in reply to the inquiry from said manager;
• when the communication with said agent incapable of communication is possible, making a reply indicating that this agent is an acting manager candidate, for said manager;
• and
• receiving said management objects of said agent incapable of communication and sending said management objects to said manager.