Node representation system, node monitor system, the methods and storage medium

• US 6,633,538 B1
• Filed: 01/07/1999
• Issued: 10/14/2003
• Est. Priority Date: 01/30/1998
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Tamura, Yasuo, Tanaka, Ryoju
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): Ferris, Derrick W
• Application Number:
  US09/226,239
• Time in Patent Office: 1,741 Days
• Field of Search: 709/208, 709/209, 709/211, 709/346, 709/700, 709/710, 709/712, 370/216, 370/218, 370/220, 370/221, 370/222, 370/223, 370/258, 370/449, 370/452, 714/1, 714/2, 714/5, 714/7, 714/13, 700/3, 710/110, 340/2.24, 340/3.1, 340/3.42, 340/3.44, 712/28
• US Class Current: 370/222
• CPC Class Codes: H04L 12/423 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/437 Ring fault isolation or reconfiguration for SDH/SONET ring networks H04J3/085

Abstract

A node representation system designates for one of a plurality of nodes for a master node and the rest for slave nodes. Each node refers to an address management table, and monitors the node of an entry next to each node in the table in order. As a result, each node monitors the node of the next entry, and simultaneously is monitored by the node of the preceding entry. When detecting a failure in a node to be monitored, a node represents the functions of the failed node, and further represents the monitoring of a node monitored by the node. When an instruction to duplicate the resource of the master node to each slave node is issued by a control node, the master node represents the functions of each slave node while duplicating.

Claims

1. A node representation system for each node representing functions provided by another node in a system where a plurality of nodes are connected through a network, the node representation system comprising:

each of the nodes includes;

an activation controlling unit obtaining information on monitoring when the node is activated;

a monitoring/representing unit monitoring a normal operation of a first other node based on information obtained by the activation controlling unit, and when a failure is detected in the first other node, representing both the monitoring of a second other node monitored by the first other node, and the functions provided by the first other node; and

a first address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of said plurality of nodes,

wherein the activation controlling unit and monitoring/representing unit of each of the nodes are controlled in such a way that a first node may monitor a normal operation of a second node, the second node may monitor the normal operation of the first node or a third node, and after which such a relation is established in order to construct one closed-looped logical monitoring network.

2. The node representation system according to claim 1, wherein

said monitoring/representing unit monitors a status of an individual function provided by said first other node, and represents the functions provided by said first node in units of individual functions, the stopping of whose provision is detected.

3. The node representation system according to claim 1,

wherein said activation controlling unit obtains the real address and virtual address of the first other node to be monitored from said first address storing unit, and

wherein said monitoring/representing unit monitors an operation of the first other node to be monitored using the real address of the first other node, and represents functions provided by the first other node using the virtual address of the first other node.

4. The node representation system according to claim 3, wherein

said first address storing unit stores the real address and virtual address of each of said nodes in a predetermined node order.

5. The node representation system according to claim 3, wherein each of said nodes further comprises:

a second address storing unit storing the real address and virtual address of each of said nodes,

wherein said activation controlling unit duplicates a contents of said first address storing unit to said second address storing unit.

6. The node representation system according to claim 3, wherein said activation controlling unit includes:

a storing unit for storing the real address and virtual address of each node in one entry of said first address storing unit in said node order; and

a searching unit searching said first address storing unit, when a storage entry of a real address next to an entry in which a real address of an own node is stored, is not a storage entry of a final real address, recognizing a node with a real address stored in the next storage entry of a real address as the first other node to be monitored, and when the storage entry of the next real address is the storage entry of a final real address, recognizing a node with a real address stored in a storage entry of a leading real address as the first other node to be monitored.

7. The node representation system according to claim 3, further comprising:

a node setting unit for storing information on the real address and virtual address of each of said nodes in said first address storing unit according to an instruction from a node connected to said network.

8. The node representation system according to claim 1, wherein said monitoring/representing unit includes:

a detecting unit detecting a restoration of a failure in the first other node both while a monitor of the second other node monitored by the first other node is monitored and functions provided by the first other node are represented; and

a representation stopping unit stopping the representation of the functions provided by the first other node when the restoration of the failure in the first other node is detected by said detecting means.

9. The node representation system according to claim 1, wherein the failure in operation of the first other node to be detected by said monitoring/representing unit is a pause of an operation in said first node.

10. The node representation system according to claim 1, further comprising:

a schedule information storing unit storing schedule information on an operation of each node, wherein, said monitoring/representing unit monitors at least one node to be monitored by the first other node and represents at least one function to be performed by the first other node, based on the schedule information stored in the schedule information storing unit.

11. The node representation system according to claim 1, further comprising:

a displaying unit displaying a screen indicating by which node a status of each of said nodes and functions of each of said nodes are represented and performed.

12. The node representation system according to claim 1, further comprising:

a controlling unit modifying said status of each node as occasion demands.

13. The node representation system according to claim 1, further comprising:

a displaying unit displaying a screen indicating by which node a status of each of said nodes and functions of each of said nodes are represented and performed; and

a controlling unit modifying the status of each of said nodes through the screen displayed by the displaying unit.

14. The node representation system according to claim 1, wherein the monitoring network is a closed-looped network where n sets of nodes are connected in a predetermined monitoring direction, and

wherein when a failure occurs in i (2≦

i≦

n−

2) sets of nodes with a node immediately before an own node as an initial stage, the monitoring/representing unit of each node monitors operations of both the i sets of nodes and a node monitored by the last node of the i sets of the node group, and represents functions provided by each of the i sets of nodes.

15. The node representation system according to claim 1,

wherein the monitoring network is a closed-looped network where n sets of nodes are connected in a predetermined monitoring direction, and

wherein when a failure occurs in (n−

1) sets of nodes with a node immediately before an own node as an initial stage, the monitoring/representing unit of each node monitors operations of the (n−

1) sets of nodes, and represents functions provided by the (n−

1) sets of nodes.

16. A node representation system for each node representing functions provided by another node in a system where a plurality of nodes are connected through a network, and out of said plurality of nodes, one is set as a master node and two or more as slave nodes, the node representation system comprising:

each of the master node and the slave nodes includes;

an activation controlling unit obtaining information on monitoring when its own node is activated; and

a monitoring/representing unit monitoring a normal operation of a first other node based on the information obtained by the activation controlling unit, when a failure is detected in the normal operation of the first other node, monitoring a normal operation of a second other node monitored by the first other node and representing functions provided by the first other node, wherein

the activation controlling unit and the monitoring/representing unit of each node control an own node in such a way that a first node may monitor the normal operation of a second node, the second node monitor may monitor a third node, and after which such a relation may be established in order and a closed-looped logical monitoring network may be constructed,

said master node and said slave nodes, further including;

a resource duplicating unit duplicating a resource from said master node to said slave nodes and representing and performing functions provided by said slave nodes using the monitoring/representing unit of said master node while the resources are duplicated; and

a first address storing unit for storing real IP (internet protocol) addresses and virtual IP addresses of each of said plurality of individual nodes.

17. The node representation system according to claim 16, wherein

said monitor/representing unit monitors a status of each function provided by said first other node, and represents functions provided by said first other node in units of individual functions, the stopping of whose provision is detected, and

said resource duplicating unit make the monitoring/representing unit of said master node represent and perform functions provided by said slave nodes in units of said individual functions.

18. The node representation system according to claim 16, wherein after said master node completes a resource duplication process of said two or more slave nodes, said resource duplicating unit makes the monitoring/representing means of said master node stop representing and performing at an appropriate timing functions of slave nodes of which said resource duplication process is completed.

19. The node representation system according to claim 16, wherein when said master node completes a resource duplication process for all of said slave nodes, said resource duplicating unit duplicates resources duplicated for said slave nodes to a running resource of said master node.

20. The node representation system according to claim 19, wherein while said resource duplicating unit is duplicating the resources duplicated for said slave nodes to its own running resource, said master node is both represented and performed functions provided by its own node by monitoring/representing means of a node monitored by its own node.

21. The node representation system according to claim 16, wherein while said master node is duplicating a resource from said master node to said slave nodes, said resource duplicating unit makes the monitoring/representing unit of said master node represent and perform a monitoring of other nodes monitored by said slave nodes.

22. The node representation system according to claim 16,

wherein a monitoring direction along a closed loop with the master node as a start point is set, and

wherein said resource duplicating unit performs a resource duplication from said master node to said slave nodes in said order of the monitoring direction.

23. The node representation system according to claim 16,

wherein said activation controlling unit of the master node and slave nodes obtains a real address and a virtual address of a first other node to be monitored from said first address storing unit,

said monitoring/representing unit of the master node and slave nodes monitors an operation of the first other node to be monitored using the real address of the first other node, and represents functions provided by said first other node using the virtual address of the first other node, and

while said resource duplicating unit are duplicating a resource from said master node to said slave nodes, said monitoring/representing unit of the master node represents and performs functions provided by said slave nodes using the virtual address of said slave nodes.

24. The node representation system according to claim 23, wherein a specific virtual address is assigned to said master node, and said specific virtual address is stored in said first address storing unit.

25. The node representation system according to claim 23, wherein said first address storing unit are provided in said master node.

26. The node representation system according to claim 25, wherein each of said slave nodes further comprises:

second address storing unit for storing a real address and a virtual address of each of said nodes, and

said activation controlling unit of each of the slave nodes duplicates a contents of the first address storing unit of the master node to said second address storing unit.

27. The node representation system according to claim 26, wherein

said first address storing unit stores a real address and a virtual address of each node in one entry in said order of nodes,

said activation controlling unit of the master node and said activation controlling unit of the slave nodes search said first and second address storing unit, respectively, if a storage entry of a real address next to an entry in which a real address of its own node is stored, is not a storage entry of a final real address, recognize a node with a real address stored in a storage entry of the next real address as a first other node to be monitored, and if the storage entry of the next real address is the storage entry of the final real address, recognize a node with a real address stored in a storage entry of a leading real address as the first other node to be monitored.

28. The node representation system according to claim 16, further comprising:

a resource duplication designating unit instructing execution of said resource duplicating unit from a control node connected to said network.

29. The node representation system according to claim 16, further comprising:

a schedule information storing unit for storing schedule information on an execution of said resource duplicating unit, wherein

said resource duplicating unit execute a process based on schedule information stored in the schedule information storing unit.

30. The node representation system according to claim 29, wherein said schedule information storing unit are provided in said master node.

31. The node representation system according to claim 29, further comprising:

a schedule designating unit storing said schedule information in said schedule information storing unit according to an instruction from said control node connected to said network.

32. The node representation system according to claim 31, wherein the instruction from said control node is reported to said master node.

33. The node representation system according to claim 32, wherein said schedule information storing unit is provided in said master node.

34. The node representation system according to claim 16, further comprising:

a node setting unit storing information related to the real address and virtual address of each of said nodes in said first address storing unit according to an instruction from a control node connected to said network.

35. The node representation system according to claim 34, wherein the instruction from said control node is reported to said master node.

36. The node representation system according to claim 35, said first address storing unit is provided in said master node.

37. The node representation system according to claim 16, further comprising:

a displaying unit displaying a screen indicating by which node a status of each of said nodes and functions of each of said nodes are represented.

38. The node representation system according to claim 16, further comprising:

a controlling unit modifying said status of each node as occasion demands.

39. The node representation system according to claim 16, further comprising:

a displaying unit displaying a screen indicating by which node a status of each of said nodes and functions of each of said nodes are represented; and

a controlling unit modifying said status of each node through a screen displayed by the displaying unit.

40. The node representation system according to claim 16,

wherein the network is a closed-looped logical monitoring network in which n sets of nodes are connected in a predetermined monitoring direction, and

wherein said monitoring/representing unit of each of the nodes monitors the i sets of nodes and a node monitored by the last node of i sets of the node group, and represents functions provided by the i sets of nodes when a failure occurs 20 in i (2<

i<

n−

2) sets of nodes with a node immediately before its own node as an initial stage.

41. The node representation system according to claim 16, wherein the network is a closed-looped logical monitoring network in which n sets of nodes are connected in a predetermined monitoring direction, and

wherein said monitoring/representing unit of each of the nodes monitors an operation of the (n−

1) sets of nodes, and represents functions provided by the (n−

1) sets of nodes when a failure occurs in (n−

1) sets of nodes with a node immediately before its own node as an initial stage.

42. A node monitoring system for each node monitoring a failure of another node in a system where a plurality of nodes are connected through a network, the node monitoring system comprising:

each node includes;

an activation controlling unit obtaining information on monitoring when being activated;

a monitoring unit monitoring a normal operation of a first other node based on information obtained by the activation controlling unit, and when a failure is detected in the normal operation of the first other node, representing a monitoring of a second node monitored by the first node;

a first address storing unit storing at least a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes,

wherein the activation controlling unit and the monitoring unit of each node control in such a way that a first node may monitor a normal operation of a second node, the second node may monitor a normal operation of the first node or a third node, after that such a monitoring relation may be established in order, and a closed-looped logical monitoring network may be constructed.

43. The node monitoring system according to claim 42, wherein said monitoring unit monitors a status of individual functions provided by said first other node, and represents a monitoring of said first other node in units of individual functions whose failure is detected.

44. The node monitoring system according to claim 42,

wherein said activation controlling unit obtains the real address and virtual address of the first other node from said first address storing unit, and

wherein said monitoring unit monitors an operation of the first other node using the real address of the first node, and represents functions provided by the first other node using the virtual address of the first other node.

45. The node monitoring system according to claim 44, wherein said first address storing unit stores said real address of each node in a predetermined order of nodes.

46. The node monitoring system according to claim 44, wherein each of said nodes further includes:

a second address storing unit storing at least said real address of each node, and

said activation controlling unit duplicates a contents of said first address storing unit to said second address storing unit.

47. The node monitoring system according to claim 46, wherein said activation controlling unit includes:

a storing unit for storing a real address of each node in one entry of said second address storing unit in a predetermined order of nodes, and

a search said second address storing unit, if a storage entry of a real address next to an entry which a real address of its own node is stored, is not a storage entry of a final real address, recognizes a node with a real address stored in a storage entry of the next real address as a first other node to be monitored, and if the storage entry of the next real address is the storage entry of the final real address, recognizes a node with a real address stored in a storage entry of a leading real address as the first other node to be monitored.

48. The node monitoring system according to claim 44, further comprising:

a node setting unit storing information related to a real address of each of said nodes in said first address storing unit according to an instruction from a node connected to said network.

49. The node monitoring system according to claim 42, wherein said monitoring unit includes:

a detecting unit detecting a restoration of the first other node while representing a monitoring of a second other node monitored by the first other node; and

a representation stopping unit stopping the representation of functions provided by the first other node when a restoration of a failure in the first other node is detected.

50. The node monitoring system according to claim 42, wherein failures in an operation of the first other node detected by said monitoring unit also include a pause of an operation of the first other node.

51. The node monitoring system according to claim 42, further comprising:

a schedule information storing unit storing schedule information on an operation of each node, wherein

said monitoring unit represents and performs monitoring to be performed by the first other node based on schedule information stored in said schedule information storing unit.

52. The node monitoring system according to claim 42, further comprising:

a displaying unit displaying a screen indicating a status of each of said nodes.

53. The node monitoring system according to claim 42, further comprising:

a controlling unit modifying a status of each of said nodes as an occasion demands.

54. The node monitoring system according to claim 42, further comprising:

a displaying unit displaying a screen indicating a status of each of said nodes; and

a controlling unit modifying a status of each of said nodes through a screen displayed by said displaying unit.

55. The node monitoring system according to claim 42,

wherein the monitoring network is a closed-looped network in which n sets of nodes are connected in a predetermined monitoring direction, and

wherein said monitoring/representing unit of each of the nodes monitors the i sets of nodes and a node monitored by the last node of i sets of the node group, and represents functions provided by the i sets of nodes when a failure occurs in i (2<

i<

n−

2) sets of nodes with a node immediately before its own node as an initial stage.

56. The node monitoring system according to claim 42,

wherein the monitoring network is a closed-looped network in which n sets of nodes are connected in a predetermined monitoring direction, and

wherein said monitoring/representing unit of each of the nodes monitors an operation of the (n−

1) sets of nodes, and represents functions provided by the (n−

1) sets of nodes when a failure occurs in (n−

1) sets of nodes with a node immediately before its own node as an initial stage.

57. A master node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, and the master node and the slave nodes provide one or more functions, the master node comprising:

a function representing unit instructing the slave nodes to stop the one or more functions provided by the slave nodes and representing the functions of the slave nodes;

a resource duplicating unit transmitting a latest resource for duplication to the slave nodes whose functions are represented using the function representing unit and duplicating the latest resource to the slave nodes;

a controlling unit restarting the functions of the slave nodes after a process of the resource duplicating unit is completed;

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

58. A slave node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, and the master node and the slave nodes provide one or more functions, the slave node comprising:

a represented unit having its own functions represented by the master node according to an instruction from the master node;

a resource duplicating unit duplicating a latest resource received from the master node as a running resource while is having its own functions represented by the master node;

a function restarting unit restarting its own functions receiving a report that a representation of its own function is terminated by the master node after a resource duplication process is completed by the resource duplicating unit; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

59. A control node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the control node comprising:

a displaying unit displaying an input screen of schedule data;

an inputting unit inputting the schedule data through the input screen displayed by the displaying unit; and

a unit transmitting the schedule data inputted through the inputting unit to the master node,

wherein the network is a closed-looped network in which n sets of nodes are connected in a predetermined monitoring direction, and wherein each node has a real IP (internet protocol) address and a virtual IP address.

60. A master node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the master node comprising:

a receiving unit receiving schedule data from the control node;

a controlling unit controlling an operation of its own node and the slave nodes based on schedule data received by said receiving unit; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

61. A slave node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, and the master node and the slave nodes provide one or more functions, the slave node comprising:

a receiving unit receiving an instruction on a predetermined operation from the master node;

an operating unit performing an instructed operation received by said receiving unit; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

62. A control node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the control node comprising:

a displaying unit displaying a list display screen of a running status of the master node or the slave nodes;

an inputting unit inputting control information for modifying the running status of the master node or slave nodes through the list display screen of the running status displayed by said displaying unit; and

a unit transmitting the control information inputted through the inputting unit to the master node,

wherein the network is a closed-looped network in which n sets of nodes are connected in a predetermined monitoring direction, and wherein each node has a real IP (internet protocol) address and a virtual IP address.

63. A control node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the control node comprising:

an obtaining unit obtaining information related to a running status of the master node or the slave nodes from the master node; and

a displaying unit displaying a list of the running status of the master node or the slave nodes based on the information on the running status obtained by said obtaining unit,

wherein the network is a closed-looped network in which n sets of nodes are connected in a predetermined monitoring direction, and wherein each node has a real IP (internet protocol) address and virtual IP address.

64. A master node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the master node comprising:

a collecting unit collecting running status information of at least one of the master node and one or more of the slave nodes;

a reporting unit reporting the running status information collected by said collecting unit; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

65. A slave node in a system where out of a plurality of nodes on a network, one is set as a master node and or more as slave nodes, and the master node and the slave nodes provide one or more functions, the slave node comprising:

a receiving unit receiving a report request on a running status from the master node;

a reporting unit reporting its own running status to the master node as a response when said receiving unit receives the report request; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

66. A master node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the master node comprising:

a receiving unit receiving control information for modifying a running status of the master node or the slave nodes from the control node;

a controlling unit controlling an operation of its own node or the slave nodes based on the control information; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

67. A slave node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, and the master node and the slave nodes provide one or more functions, the slave node comprising:

a receiving unit receiving an instruction on a predetermined operation from the master node;

an operating unit performing the instructed operation received by said receiving unit; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

68. A control node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the control node comprising:

an inputting unit inputting information related to each node; and

a transmitting unit transmitting the information inputted by said inputting unit to the master node,

wherein the network is a closed-looped network in which n sets of nodes are connected in a predetermined monitoring direction, and wherein each node has a real IP (internet protocol) address and a virtual IP address.

69. The control node according to claim 68, whe rein said information related to each node include at least one of a master class, an address on the network, an address of a node to be monitored, contents of monitor ing services and existence/non-existence of a representation operation.

70. A master node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, further out of the plurality of nodes one is set as a control node, and the master node and the slave nodes provide one or more functions, the master node comprising:

a receiving unit receiving information related to each node;

a storing unit storing the information received by said receiving unit; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

71. The master node according to claim 70, wherein said information related to each node include at least one of a master class, an address on the network, the real and virtual addresses of a node to be monitored, contents of monitoring services and existence/nonexistence of a representation operation.

72. A slave node in a system where out of a plurality of nodes on a network, one is set as a master node and two or more as slave nodes, and the master node and the slave nodes provide one or more functions, the slave node comprising:

a receiving unit receiving the information from said storing unit of the master node in which information related to said each node is stored, at a predetermined timing;

a storing unit storing the information received by said receiving unit; and

an address storing unit storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

73. The slave node according to claim 72, wherein said information related to said each node include at least one of a master class, an address on the network, the real and virtual addresses of a node to be monitored, contents of monitoring services and existence/non existence of a representation operation.

74. A node representation method of a plurality of nodes on a network representing functions provided by other nodes, said method comprising:

controlling an activation of each node in such a way that a first node may monitor a normal operation of a second node, the second node may monitor a normal operation of the first node or a third node, after which such a monitoring relation may be established in order, a logical monitoring network in one closed loop form may be constructed, and as a result, the first node may also be monitored by a node other than the first node;

detecting at each of said nodes a failure in a node to be monitored, representing functions provided by the node to be monitored and monitoring of another node monitored by the node to be monitored at a node having detected the failure; and

storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

75. A node representation method of a plurality of nodes on a network representing functions provided by other nodes, said method comprising:

controlling an activation of each node in such away that.a first node may monitor a normal operation of a second node, the second node may monitor a normal operation of the first node or a third node, after which such a monitoring relation may be established in order, a logical monitoring network in one closed loop form may be constructed, and as a result, the first node may also be monitored by a node other than the first node;

setting out of the plurality of nodes, one as a master node and one or more as slave nodes, duplicating a resource from the master node to at least one of slave nodes, and making the master node represent functions provided by the slave nodes during the resource duplication; and

storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

76. A node representation method of a plurality of nodes on a network representing functions provided by other nodes, said method comprising:

controlling an activation of each node in such a way that a first node may monitor a normal operation of a second node, the second node may monitor a normal operation of the first node or a third node, after which such a monitoring relation may be established in order, a logical monitoring network in one closed loop form may be constructed, and as a result, the first node may also be monitored by a node other than the first node;

detecting at each of said nodes a failure in a node to be monitored and representing monitoring of another node monitored by the node to be monitored at a node having detected the failure; and

storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

77. A computer readable storage medium for storing a program to enable a computer to implement a node representation method of a plurality of nodes on a network representing functions provided by other nodes, the program comprising:

controlling an activation of each node in such a way that a first node may monitor a normal operation of a second node, the second node may monitor a normal operation of the first node or a third node, after which such a monitoring relation may be established in order, a logical monitoring network in one closed loop form may be constructed, and as a result, the first node may also be monitored by a node other than the first node;

detecting at each of said nodes a failure in a node to be monitored, representing functions provided by the node to be monitored and monitoring of another node monitored by the node to be monitored at a node having detected the failure; and

storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

78. A computer readable storage medium for storing a program to enable a computer to implement a node representation method of a plurality of nodes on a network representing functions provided by other nodes, the program comprising:

controlling an activation of each node in such a way that a first node may monitor a normal operation of a second node, the second node may monitor a normal operation of the first node or a third node, after which such a monitoring relation may be established in order, a logical monitoring network in one closed loop form may be constructed, and as a result, the first node may also be monitored by a node other than the first node;

setting out of the plurality of nodes, one as a master node and one or more as slave nodes, duplicating a resource from the master node to at least one of the slave nodes, and making the master node represent functions provided by the slave nodes during the resource duplication; and

storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

79. A computer readable storage medium for storing a recorded program to enable a computer to implement a node representation method of a plurality of nodes on a network representing functions provided by other nodes, the program comprising:

controlling an activation of each node in such a way that a first node may monitor a normal operation of a second node, the second node may monitor a normal operation of the first node or a third node, after which such a monitoring relation may be established in order, a logical monitoring network in one closed loop form may be constructed, and as a result, the first node may also be monitored by a node other than the first node;

detecting at each of said nodes a failure in a node to be monitored and, representing monitoring of another node monitored by the node to be monitored at a node having detected the failure; and

storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes.

80. A node representation method of a plurality of nodes on a network representing functions provided by other nodes, comprising:

establishing a logical monitoring network comprising n sets of nodes, wherein a first node may monitor a normal operation of a second node, and the second node may monitor a normal operation of the first node or a third node;

storing a real IP (internet protocol) address and a virtual IP address of each of the plurality of nodes;

detecting a failure in a node to be monitored; and

monitoring another node, which is monitored by the node to be monitored, at a node that detected the failure.

81. A node representation system for each node representing a function provided by another node in a system where a plurality of nodes are connected through a network, the node representation system comprising:

an address management table for storing pairs of a real address and a virtual address of the plurality of nodes successively in a predetermined node order,

wherein each of the plurality of nodes comprises;

an activation controlling unit to obtain a pair of a real IP (internet protocol) address and a virtual IP address succeeded to the node'"'"'s address in the address management table when the node is activated; and

a monitoring/representing unit to monitor a normal operation of a first other node whose address is obtained by the activation controlling unit, and when a failure is detected in the first other node, to represent both the monitoring of a second other node that is monitored by the first other node and the functions provided by the first other node.