Abstract:
In an information processing system comprising a redundantly furnished plurality of second information processing apparatuses being commonly connected with a first information processing apparatus through an information transmission path to supervise the first information processing apparatus, and a third information processing apparatus being connected with the second information processing apparatus through an information network to manage the second information processing apparatus, wherein each of the second information processing apparatuses comprises a connection confirmation control logic for trying to transmit connection confirmation information to the third information processing apparatus through the information network in compliance with an instruction being given by the one representative second information processing apparatus, and the third information processing apparatus comprises a maintenance management control logic for collecting the connection confirmation information arriving from each of the second information processing apparatuses and transmitting collected results by e-mail to a manager of the first information processing apparatus.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an information processing system, a control method of same, a supervisory apparatus, a maintenance management apparatus, a supervisory program and a maintenance management program, and in particular to a supervisory technique for an information processing apparatus required for a stable operation for a long period of time, and further to an effective technique applicable to a remote maintenance technique, et cetera, by utilizing a network.  
         [0003]     2. Description of the Related Art  
         [0004]     In conventional information processing apparatuses such as servers required to provide a stable operation, a continuous supervision of error status, unaffected by a failure in a supervisory apparatus, has been enabled by furnishing a plurality of supervisory apparatuses redundantly for the aforementioned supervision of the information processing apparatus for instance as seen in the patent document 1 listed below. It is also conceivable to perform an error information monitoring and a centralized management for supervisory apparatuses by connecting the plurality thereof to a remotely located maintenance management center by way of a network.  
         [0005]     There is also a method for a representative supervisory apparatus, among a plurality thereof being furnished redundantly, to report an error status as disclosed by the patent document 2 listed below.  
         [0006]     Incidentally, when furnishing supervisory apparatuses redundantly and managing them remotely at a maintenance center, an independent communication path becomes a necessity for connection between the individual supervisory apparatus and the maintenance center. In other words, in case the respective communication paths between the maintenance center and each supervisory apparatus are made common, a failed representative supervisory apparatus may not be replaceable by another of such apparatus if there is a failure in the common communication path, hence all the supervisory apparatuses becoming incommunicable with the maintenance center, and thus making the redundancy of supervisory apparatuses meaningless.  
         [0007]     When thus furnishing the supervisory apparatuses redundantly and making the communication path between each supervisory apparatus and the maintenance center independent from one another, it is necessary to confirm a connection between each supervisory apparatus and the maintenance center one by one at the time of starting up the supervisory system in preparation of starting up a random supervisory apparatus for replacing a failed one.  
         [0008]     In the case of a plurality of supervisory apparatuses being present under management, however, a cumbersome operation is required for each of the plurality thereof such as a confirmation of connection by the operator of the supervisory apparatus individually starting up the connection program and trying to connect with the maintenance center, while the management center repeatedly sending a response mail to the installer of the information processing apparatus as an object of supervision (“supervision object (information) apparatus” hereinafter) for confirming the connection result of every applicable apparatus, taking time in proportion to the number of such installed apparatuses. Such has been a technical problem.  
         [0009]     In recent years, a centralized management of many information processing apparatuses by installing them in a specific site has become common where a redundancy of supervisory apparatuses is inevitable for maintaining a stable operation, making it increasingly cumbersome to operate the connection confirmations respectively for the supervisory apparatuses as described above.  
         [0010]     Meanwhile, if the network is erratic between the supervisory apparatus, having no problem, and the maintenance center, then there is no way for the maintenance center to judge whether the failure occurring in a supervisory apparatus is caused by itself or the network, making the maintenance center unable to correctly provide the supervisory apparatus with a solution to the failure. Such has been another technical problem.  
         [0011]     And in the case of having a representative supervisory apparatus from among the redundantly furnished ones report to the maintenance center, a failure in the representative supervisory apparatus will be replaced by another representative apparatus being chosen from among the remaining ones for a continuous supervision. If the problem is stemming from a failure in the network, however, a switching from the representative to another supervisory apparatus will not occur because there is nothing wrong with the representative supervisory apparatus, hence a report will not reach the maintenance center. Such is yet another technical problem.  
         [0012]     [Patent document 1] Japanese patent laid-open application publication 2003-308261  
         [0013]     [Patent document 2] Japanese patent laid-open application publication 2001-23064  
       SUMMARY OF THE INVENTION  
       [0014]     The purpose of the present invention is to provide a technique capable of performing a quick and correct operation of confirming connection for a remote maintenance of redundantly furnished supervisory apparatuses by using a network in a short time.  
         [0015]     Another purpose of the present invention is to provide a technique capable of accomplishing a stable operation by redundantly furnishing supervisory apparatuses without being affected by a failure in network in order to perform a remote maintenance of redundantly furnished supervisory apparatuses by using a network.  
         [0016]     Yet another purpose of the present invention is to provide a technique capable of achieving a stable operation by appropriately switching a failed supervisory apparatus to another without being affected by a failure in the network in order to perform a remote maintenance of redundantly furnished supervisory apparatuses by using a network.  
         [0017]     The first aspect of the present invention is to provide an information processing system comprising a redundantly furnished plurality of second information processing apparatuses being commonly connected with a first information processing apparatus by way of an information transmission path in order to supervise the first information processing apparatus, and a third information processing apparatus being connected with the second information processing apparatus by way of an information network in order to manage the second information processing apparatus, wherein  
         [0018]     each of the second information processing apparatuses comprises a connection confirmation control logic for trying to transmit connection confirmation information to the third information processing apparatus by way of the information network in compliance with an instruction being given by the one representative second information processing apparatus, and  
         [0019]     the third information processing apparatus comprises a maintenance management control logic for collecting the connection confirmation information arriving from each of the second information processing apparatuses and transmitting a result of collecting the connection confirmation information by electronic mail (“e-mail” hereinafter) to a manager of the first information processing apparatus.  
         [0020]     The second aspect of the present invention is to provide a control method for an information processing system comprising a redundantly furnished plurality of second information processing apparatuses being commonly connected with a first information processing apparatus by way of an information transmission path in order to supervise the first information processing apparatus, and a third information processing apparatus being connected with the second information processing apparatus by way of an information network in order to manage the second information processing apparatus, comprising:  
         [0021]     a first process in which each of the second information processing apparatuses tries to transmit connection confirmation information to the third information processing apparatus by way of the information network in compliance with an instruction being given by the one representative second information processing apparatus; and  
         [0022]     a second process in which the third information processing apparatus collects the connection confirmation information arriving from each of the second information processing apparatuses and transmits a result of collecting the connection confirmation information by e-mail to a manager of the first information processing apparatus.  
         [0023]     The third aspect of the present invention is to provide a supervisory apparatus, being a supervisory apparatus connected to a supervision object apparatus by way of an information transmission path in order to supervise the supervision object apparatus, comprising a connection confirmation control logic for accomplishing the functions of  
         [0024]     performing a connection confirmation with a maintenance management apparatus by way of a information network, prompted by an instruction from another of redundantly furnished supervisory apparatuses commonly connected with the information transmission path;  
         [0025]     requesting another of the said supervisory apparatuses for a substitute transmission of connection error information indicating a failure in transmitting connection confirmation information, of the connection confirmation information and of an alternative connection path to the maintenance management apparatus by way of said information transmission path, if the connection confirmation is failed; and  
         [0026]     performing the substitute transmission requested by the other supervisory apparatus.  
         [0027]     The fourth aspect of the present invention is to provide a maintenance management apparatus which is a maintenance management apparatus for collecting maintenance management information related to a plurality of redundantly furnished supervisory apparatuses, being connected with a supervision object apparatus by way of an information transmission path, from the supervisory apparatuses via an information network, comprising a maintenance management control logic for  
         [0028]     collecting connection confirmation information indicating a successful connection with the maintenance management apparatus arriving from each of a plurality of the supervisory apparatuses and transmitting a result of collecting the connection confirmation information by e-mail to a manager of the supervision object apparatus.  
         [0029]     The fifth aspect of the present invention is to provide a signal carrying a supervisory program, which is for controlling a supervisory apparatus being connected with a supervision object apparatus by way of an information transmission path in order to supervise the supervision object apparatus, making the supervisory apparatus accomplish the functions of  
         [0030]     performing a connection confirmation with a maintenance management apparatus by way of a information network, prompted by an instruction from another of redundantly furnished supervisory apparatuses commonly connected with the information transmission path;  
         [0031]     requesting another of the said supervisory apparatuses for a substitute transmission of connection error information indicating a failure in transmitting connection confirmation information, of the connection confirmation information and of an alternative connection path to the maintenance management apparatus by way of said information transmission path, if the connection confirmation is failed; and  
         [0032]     performing the substitute transmission requested by the other supervisory apparatus.  
         [0033]     The sixth aspect of the present invention is to provide a signal carrying a maintenance management program, which controls a maintenance management apparatus for collecting maintenance management information related to a plurality of redundantly furnished supervisory apparatuses, being connected with a supervision object apparatus by way of an information transmission path, from the supervisory apparatuses via an information network, making the maintenance management apparatus accomplish the functions of  
         [0034]     collecting connection confirmation information indicating a successful connection with the maintenance management apparatus arriving from each of a plurality of the supervisory apparatuses and transmitting a result of collecting the connection confirmation information by e-mail to a manager of the supervision object apparatus. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]      FIG. 1  is a sequence chart exemplifying an operation of an information processing system according to an embodiment of the present invention;  
         [0036]      FIG. 2  is a conceptual diagram exemplifying a configuration of information processing system according to an embodiment of the present invention;  
         [0037]      FIG. 3  is a block diagram exemplifying a configuration of supervisory apparatus constituting an information processing system according to an embodiment of the present invention;  
         [0038]      FIG. 4  is a block diagram exemplifying a configuration of maintenance management apparatus constituting an information processing system according to an embodiment of the present invention;  
         [0039]      FIG. 5  is a conceptual chart exemplifying information being used by a supervisory apparatus according to an embodiment of the present invention;  
         [0040]      FIG. 6  is a conceptual chart exemplifying information being used by a supervisory apparatus according to an embodiment of the present invention;  
         [0041]      FIG. 7  is a conceptual chart exemplifying information being used by a maintenance management apparatus according to an embodiment of the present invention;  
         [0042]      FIG. 8  is a conceptual diagram exemplifying data transmitted at the time of connection confirmation by a supervisory apparatus according to an embodiment of the present invention;  
         [0043]      FIG. 9  is a conceptual diagram exemplifying data transmitted at the time of connection confirmation by a supervisory apparatus according to an embodiment of the present invention;  
         [0044]      FIG. 10  is a conceptual diagram exemplifying data transmitted at the time of error report by a supervisory apparatus according to an embodiment of the present invention;  
         [0045]      FIG. 11  is a conceptual diagram exemplifying data transmitted at the time of error report by a supervisory apparatus according to an embodiment of the present invention;  
         [0046]      FIG. 12  is a flow chart exemplifying an operation of a supervisory apparatus according to an embodiment of the present invention;  
         [0047]      FIG. 13  is a flow chart exemplifying an operation of a supervisory apparatus according to an embodiment of the present invention;  
         [0048]      FIG. 14  is a flow chart exemplifying an operation of a supervisory apparatus according to an embodiment of the present invention;  
         [0049]      FIG. 15  is a flow chart exemplifying an operation of a supervisory apparatus according to an embodiment of the present invention;  
         [0050]      FIG. 16  is a flow chart exemplifying an operation of a maintenance management apparatus according to an embodiment of the present invention;  
         [0051]      FIG. 17  is a conceptual diagram exemplifying an e-mail transmitted at the time of a connection confirmation by a maintenance management apparatus according to an embodiment of the present invention; and  
         [0052]      FIG. 18  is a conceptual diagram exemplifying an e-mail transmitted at the time of a connection confirmation by a maintenance management apparatus according to an embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0053]     A detailed description of an embodiment of the present invention will be given as follows while referring to the accompanying drawings.  
         [0054]      FIG. 1  is a sequence chart exemplifying an operation of an information processing system according to an embodiment of the present invention;  FIG. 2  is a conceptual diagram exemplifying a configuration of information processing system according to an embodiment of the present invention;  FIG. 3  is a block diagram exemplifying a configuration of supervisory apparatus constituting an information processing system according to the present embodiment; and  FIG. 4  is a block diagram exemplifying a configuration of maintenance management apparatus constituting an information processing system according to the present embodiment.  
         [0055]      FIGS. 5 and 6  are conceptual charts each exemplifying information being used by a supervisory apparatus according to the present embodiment; and  FIG. 7  is a conceptual chart exemplifying information being used by a maintenance management apparatus according to the present embodiment.  
         [0056]      FIGS. 8 and 9  are conceptual diagrams each exemplifying data transmitted at the time of connection confirmation by a supervisory apparatus according to the present embodiment; and  FIGS. 10 and 11  are conceptual diagrams exemplifying data transmitted at the time of error report by a supervisory apparatus according to the present embodiment.  
         [0057]      FIGS. 12, 13 ,  14  and  15  are flow charts each exemplifying an operation of a supervisory apparatus according to the present embodiment; and  FIG. 16  is a flow chart exemplifying an operation of a maintenance management apparatus according to the present embodiment.  
         [0058]     As exemplified by  FIG. 2 , an information processing system according to the present embodiment comprises for instance a supervision object apparatus  10  (i.e., first information processing apparatus) made up of information apparatuses such as a mainframe computer required for a stable continuous operation for a long period of time, a server apparatus, et cetera, and a redundantly furnished plurality of supervisory apparatuses  20  (i.e., second information processing apparatus) for supervising the operations of the supervision object apparatus  10 .  
         [0059]     Each of the supervisory apparatuses  20 , being interconnected by a redundantly furnished general purpose bus and a general purpose bus, is also connected to the supervision object apparatus  10 .  
         [0060]     That is, the information exchanges among the supervisory apparatuses  20 , and the information exchange between each of the supervisory apparatuses  20  and the supervision object apparatus  10 , are adequately enabled if either one of the furnished general purpose buses  31  and  32  fails.  
         [0061]     As such, a redundantly furnished plurality of supervisory apparatuses  20  are provided for the supervision object apparatus  10  in order to assure a stable supervision in the present embodiment.  
         [0062]     Each of the supervisory apparatuses  20  is connected to an information network  40  such as a wide area information network by way of a mutually independent plurality of communication paths  40   a , and is further connected with, for instance, a remotely located maintenance management apparatus  50  (i.e., third information processing apparatus) by way of the information network  40 .  
         [0063]     As exemplified by  FIG. 3 , the supervisory apparatus  20  according to the present embodiment for example comprises an MPU  21  for controlling the whole system, a main storage  22  for storing a program and data executed by the MPU  21 , a display  23  for visualizing the information for providing to the user, a keyboard  24  provided for the user inputting information, a plurality of general purpose bus adaptors  25  for connecting with a redundantly furnished general purpose bus  31  and a bus  32 , a network interface  26  for connecting with an information network  40  by way of a communication path  40   a , a nonvolatile storage apparatus  27  for storing information renewably and sustainedly and an internal bus  28  for interconnecting each of the aforementioned components.  
         [0064]     In the case of the present embodiment, the main storage  22  stores a supervisory program  61  (i.e., connection confirmation control logic) for the supervisory apparatus  20  accomplishing processing as exemplified by the later described flow charts shown by  FIGS. 12 through 15 . The supervisory program  61  is stored in the nonvolatile storage apparatus  27  and will be loaded onto the main storage  22  so as to be executed by the MPU  21  as required. Alternatively the supervisory program  61  may be loaded onto the nonvolatile storage apparatus  27  from the outside by way of the communication path  40   a  and the information network  40 .  
         [0065]     The nonvolatile storage apparatus  27  also stores such information as a later described supervisory apparatus management table  70  and supervision object apparatus management table  80  which will be accessed by an MPU  51 .  
         [0066]     As exemplified by  FIG. 4 , a maintenance management apparatus  50  according to the present embodiment comprises an MPU  51  for controlling the whole system, a main storage  52  for storing a program and data to be executed by the MPU  51 , a display  53  for visualizing the information for displaying, a keyboard  54  for the user inputting information, a network interface  55  for connecting the maintenance management apparatus  50  to the information network  40 , a nonvolatile storage  56  for renewably and sustainedly storing information and an internal bus  57  for interconnecting each of the aforementioned components.  
         [0067]     In the case of the present embodiment, the main storage stores a maintenance management program  62  (i.e., maintenance management control logic) which will be executed by the MPU  51  for the maintenance management apparatus  50  accomplishing the processing exemplified by a later described flow chart associated with  FIG. 16 .  
         [0068]     The maintenance management program  62  is stored in the non volatile storage  56 , readout to the main storage  52  and executed by the MPU  51 . Alternatively, the maintenance management program  62  may be installed into the nonvolatile storage  56  from the outside by way of the information network  40 .  
         [0069]     The nonvolatile storage  56  stores a later described connection management table  90  which will be accessed by the MPU  51 .  
         [0070]     As exemplified by  FIG. 5 , the supervisory apparatus management table  70  is installed in each of the supervisory apparatuses  20  and used for respectively managing the apparatus itself and the redundantly furnished other supervisory apparatuses  20 .  
         [0071]     That is, the supervisory apparatus management table  70  stores the ID on general purpose bus  71  assigned fixedly and uniquely to each supervision object apparatus  10  and each of a plurality of supervisory apparatuses  20  all of which are connected onto the general purpose bus  31  (and general purpose bus  32 ), the supervisory apparatus number  72  assigned changeably and uniquely to each of the plurality of supervisory apparatuses  20 , the error flag  73  for managing a presence or absence of error in each supervisory apparatus  20  and the management information  74  with regard to each supervisory apparatus  20  with the aforementioned information being in correspondence to the ID on general purpose bus  71  respectively.  
         [0072]     The supervision object apparatus management table  80  exemplified by  FIG. 6  is installed in each supervisory apparatus  20 , and is stored by the supervision object apparatus ID  81  being uniquely assigned to the supervision object apparatus  10  and by failure information  82  occurring in the supervision object apparatus  10  being specified by the supervision object apparatus ID  81 .  
         [0073]     The connection management table  90  exemplified by  FIG. 7  is installed in the maintenance management apparatus  50  and used for managing connection status of the supervisory apparatus  20  being allocated to each supervision object apparatus  10  with the aforementioned maintenance management apparatus  50 .  
         [0074]     That is, the connection management table  90  stores the supervision object apparatus ID  91  for specifying the supervision object apparatus  10  corresponding to the supervisory apparatus  20  as the object of connection management, the time stamp  92  indicating the time of day (“TOD” hereinafter) when the connection management table  90  is generated, the supervisory apparatus number  93  (corresponding to the above noted supervisory apparatus number  72 ) being assigned to the supervisory apparatus  20  as the object of connection management, the connection flag  94  indicating a completion or incompletion of connection confirmation and the management information  95  for managing each supervisory apparatus  20  being specified by the supervisory apparatus number  93 .  
         [0075]      FIG. 8  exemplifies a connection confirmation transmission data  41  transmitted at the time of connection confirmation by each supervisory apparatus  20  to the maintenance management apparatus  50 .  
         [0076]     The connection confirmation transmission data  41  includes a supervision object apparatus ID  41   a  for identifying the supervision object apparatus  10  to which the sending supervisory apparatus  20  belongs, a supervisory apparatus number  41   b  indicating the sending supervisory apparatus  20 , an event category  41   c , constitution information  41   d  and a transmission TOD  41   e . The event category  41   c  indicates the category of event prompting to send the connection confirmation transmission data  41 . The constitution information  41   d  includes a pair of information being made up of the total number of the redundantly furnished supervisory apparatuses  20  for supervising the aforementioned supervision object apparatus  10  and a supervisory apparatus number  41   b  for the sending supervisory apparatus  20 .  
         [0077]      FIG. 9  exemplifies a connection confirmation substitute transmission data  41 - 1  transmitted as a substitute transmission at the time of connection confirmation.  
         [0078]     The connection confirmation substitute transmission data  41 - 1  further includes network related information  41   f  in addition to the content of the above noted connection confirmation transmission data  41 . The network related information  41   f  includes the network information related to the communication path  40   a  and information network  40  collected and handed out to a substitute supervisory apparatus  20  by the supervisory apparatus  20  which has fallen to a path failure, information on an alternative path collected by the substitute supervisory apparatus  20 , et cetera.  
         [0079]      FIG. 10  exemplifies error report transmission data  42  transmitted at the time of reporting error in a supervision object apparatus  10  to the maintenance management apparatus  50  by a supervisory apparatus  20 .  
         [0080]     The error report transmission data  42  includes the supervision object apparatus ID  42   a  for a supervision object apparatus  10 , the supervisory apparatus number  42   b  for the sending supervisory apparatus  20 , an event category  42   c , a transmission TOD  42   d  and error information  42   e  indicating the detail of the error occurring in a supervision object apparatus  10 .  
         [0081]      FIG. 11  exemplifies an error report substitute transmission data  42 - 1  for use by a supervisory apparatus  20  substituting itself for another supervisory apparatus  20  in reporting error information thereof to the maintenance management apparatus  50 .  
         [0082]     The error report substitute transmission data  42 - 1  includes network related information  42   f  such as the network information related to the communication path  40   a  and information network  40  that has been collected and handed out to a substitute supervisory apparatus  20  by a failed supervisory apparatus  20 , which is different from the connection confirmation transmission data  41 . In this case, information indicating “error report” and “substitute transmission” is set for the event category  42   c.    
         [0083]     As described above, a supervision object apparatus ID  81  is assigned to each chassis of the supervision object apparatuses  10  required for assuring a stable operation.  
         [0084]     The maintenance management apparatus  50  (i.e., maintenance center) identifies a group to which the supervision object apparatus  10  belongs by the supervision object apparatus ID  41   a  and the supervision object apparatus ID  42   a  (that is, supervision object apparatus ID  81 ) included in the report contents shown by  FIGS. 8 through 11  (i.e., connection confirmation transmission data  41 , connection confirmation substitute transmission data  41 - 1 , error report transmission data  42  and error report substitute transmission data  42 - 1 ).  
         [0085]     Meanwhile, although a server apparatus as the supervision object apparatus  10  has a plurality of partitions within itself which are operated by the respectively different operating systems (OS), they are all managed by a single supervision object apparatus ID  81  in the case of the present embodiment. That is, the supervision object apparatus  10  is managed by a unit of mechanical case for a failure supervision provided by the supervisory apparatus  20 .  
         [0086]     The following describes operations of the present embodiment.  
         [0087]     When supervisory apparatuses  20  are started initializing, they identify one another and establish a representative supervisory apparatus  20 A. The supervisory apparatuses  20  compare the connection positions (i.e., ID on general purpose bus  71 ) for one another on the general purpose buses  31  and  32  and elect the supervisory apparatus  20  at the youngest connection position as the representative supervisory apparatus  20 A.  
         [0088]     That is, each of the supervisory apparatuses  20  is assigned by a continuous supervisory apparatus number  72  in order of the ID on general purpose bus  71 , and the supervisory apparatus  20  having the youngest number in the supervisory apparatus number  72  becomes the representative supervisory apparatus  20 A.  
         [0089]     And, configuration such as the number of connected supervisory apparatuses  20  and status are comprehended in this process and accordingly the information such as the ID on general purpose bus  71 , the supervisory apparatus number  72 , the error flag  73 , the management information  74 , et cetera, are stored in the supervisory apparatus management table  70  possessed by each of the supervisory apparatuses  20 .  
         [0090]     Only the representative supervisory apparatus  20 A collects a detail of error information for the supervision object apparatus  10  and reports it to the maintenance center. If the representative supervisory apparatus  20 A becomes inoperable, then the remaining apparatuses elect a new representative supervisory apparatus  20 A.  
         [0091]     Meanwhile, each supervisory apparatus  20  has the detail of error information collected from the supervision object apparatus  10  by the representative supervisory apparatus  20 A in the supervision object apparatus management table  80  being installed therein, thus being enabled for taking over the supervisory operation immediately for the supervision object apparatus  10  when the apparatus itself is elected as the representative supervisory apparatus  20 A.  
         [0092]     All of the plurality of supervisory apparatuses  20  must be made normally connectible to the maintenance management apparatus  50  located in the maintenance center.  
         [0093]     Therefore, it is necessary to perform a connection confirmation with the maintenance center when installing an apparatus.  
         [0094]     As the installer of an apparatus (i.e., operator  101 ) selects a connection confirmation from among the menu started out on the representative supervisory apparatus  20 A, the connection confirmations are automatically performed by the representative supervisory apparatus  20 A and all the other supervisory apparatuses  20  being automatically started by the instruction from the aforementioned representative supervisory apparatus  20 A. The maintenance management apparatus  50  at the maintenance center receives a connection report (i.e., connection confirmation transmission data  41 ) including the total number of supervisory apparatuses  20  (i.e., constitution information  41   d  shown by  FIG. 8 ) from the representative supervisory apparatus  20 A.  
         [0095]     As the connection reports arrive from all the supervisory apparatuses  20 , the maintenance management apparatus  50  at the maintenance center sends out e-mail (i.e., connection confirmation mail  43 ) to the apparatus installer terminal  100  of the apparatus installer in such context as shown by  FIG. 17  as a notice of confirming normal connections for all the communication paths. The upper part of the sequence chart of  FIG. 1  shows such successful connection confirmations with all the supervisory apparatuses  20  within a predefined time.  
         [0096]     If connection confirmations are done only for a part of the paths (i.e., apart of supervisory apparatuses  20 ) within a predefined time, the maintenance management apparatus  50  at the maintenance center sends out a connection confirmation mail  44  (i.e., e-mail) to the apparatus installer in such context as shown by  FIG. 18  as a notice of confirming connections with a part of the supervisory apparatuses  20 . That is, while the maintenance center waits for a completion of connection confirmations for all the supervisory apparatuses  20  until the end of a maximum time T 1  (e.g., 10 minutes), the maintenance center sends out notice of a partial connection confirmation, if only a part of the apparatuses is confirmed for the connection within the time T 1  in the present embodiment.  
         [0097]     When failing to connect with the maintenance center, the supervisory apparatus  20  collects the network information related to the communication path  40   a  and the information network  40  with which the supervisory apparatus itself is connected and requests another supervisory apparatus  20  (e.g., the representative supervisory apparatus  20 A) for reporting to the maintenance center as a connection confirmation substitute transmission data  41 - 1  shown by  FIG. 9 . Meanwhile, the other supervisory apparatus  20 , having received the request, collects also the network information, compiles network related information  41   f  including the information being handed out by the requesting supervisory apparatus and accordingly reports it. Having received the information about the point of failure in the network, the maintenance center will be able to issue an instruction for a corrective action with regard to the error in setting information or the point of failure in the network connection.  
         [0098]     Meanwhile, if the elapsed time from the completion of a part of connection paths for supervisory apparatuses  20  to the arrival of error information is within the time T 1 , the maintenance center sends back to the apparatus installer terminal  100  of the apparatus installer by a single e-mail (e.g., connection confirmation mail  44  shown by  FIG. 18 ) compiling the facts that connection confirmations for a part of the paths has succeeded while the remaining part has failed, together with an analysis result for the failed parts. The lower part of  FIG. 1  exemplifies a sequence of substitute transmission between the supervisory apparatuses  20  at the time of error.  
         [0099]     If the elapsed time to an arrival of error information at the maintenance center is more than T 1 , the maintenance management apparatus  50  sends out one e-mail (i.e., connection confirmation mail  44 ) notifying of confirming connection for a part of apparatuses in a T 2  time (e.g., one day) (larger than T 1 ) followed by another e-mail notifying a failed connection for a part of the paths and the analysis result of the failed network information to the apparatus installer terminal  100 .  
         [0100]     In the meantime, a condition of the information network  40  or the communication path  40   a  may change after a successful connection of the supervisory apparatuses  20 .  
         [0101]     In order to confirm a normalcy of the network connections, all the supervisory apparatuses  20  perform a periodical connection with the maintenance management apparatus  50  at the maintenance center. In the periodical connection, the supervisory apparatuses  20  notify the maintenance center of the next periodical connection time. The maintenance center canal so detect an abnormality if the periodical connection is not done past the scheduled time.  
         [0102]     If an abnormality occurs in a supervision object apparatus  10 , the representative supervisory apparatus  20 A collects the error information within the supervision object apparatus  10  by way of the redundantly furnished general purpose bus  31  and the general purpose bus  32 . The representative supervisory apparatus  20 A also notifies the maintenance management apparatus  50  at the maintenance center of the collected information as an error report in which the error report transmission data  42  exemplified by  FIG. 10  is used.  
         [0103]     If an error occurs in a non-representative supervisory apparatus  20 , the supervisory apparatus  20  collects the error information about itself, and also requests the representative supervisory apparatus  20 A for reporting the error information about the aforementioned supervisory apparatus  20  to the maintenance management apparatus  50 .  
         [0104]     If the representative supervisory apparatus  20 A finds itself erratic, it collects the error information about itself and also requests another supervisory apparatus  20  (i.e., a representative supervisory apparatus  20 A in the next rank of the supervisory apparatus number  72  in this case) for notifying the error information about the erratic representative supervisory apparatus  20 A and starting operation as new representative supervisory apparatus  20 A, thus ending an operation of itself as a supervisory apparatus  20 .  
         [0105]     The switching of representative supervisory apparatuses  20 A will be notified to all the other supervisory apparatuses  20 A by way of the general purpose buses  31  and  32 .  
         [0106]     The error report substitute transmission data  42 - 1  shown by  FIG. 11  indicates information used for a substitute report when an error occurs either in a supervisory apparatus  20  or the representative supervisory apparatus  20 A as described above. The error report substitute transmission data  42 - 1  includes network related information  42   f  in addition to the format for the connection confirmation transmission data  41 .  
         [0107]     If a connection of the representative supervisory apparatuses  20 A by way of the information network  40  does not work out and hence a report does not reach the maintenance management apparatus  50  at the maintenance center, the representative supervisory apparatuses  20 A collects the information about the communication path  40   a  and the information network  40 , and then requests another supervisory apparatus  20  for notifying the maintenance center of the network information and the error information.  
         [0108]     As described above, if the representative supervisory apparatus  20 A is normal while the communication path  40   a  and the information network  40  between the representative supervisory apparatus  20 A and the maintenance management apparatus  50  is problematic, the representative supervisory apparatus  20 A can be switched correctly to another supervisory apparatus  20  in the present embodiment.  
         [0109]     The supervisory apparatus  20 , having received the above described request, also collects the information relating to the information network  40  and reports the collected information content together with the content requested by the representative supervisory apparatus  20 A to the maintenance management apparatus  50  at the maintenance center by using a substitute transmission indicating that it is a transmission being requested for. A transmission data format the same as the connection confirmation substitute transmission data  41 - 1  as exemplified in  FIG. 9  can be used in this occasion.  
         [0110]     The maintenance management apparatus  50  at the maintenance center is able to identify an abnormality of connection condition by receiving the substitute transmission from the representative supervisory apparatus  20 A. The report reaching at the maintenance center as to where the error is occurring in the information network  40  and the communication path  40   a  enables the maintenance management apparatus  50  at the maintenance center to notify the operator of the representative supervisory apparatus  20 A and the apparatus installer terminal  100  of an error in setting information or the connection condition of the information network  40  and the communication path  40   a . As a result, the apparatus installer is empowered to instruct the supervisory apparatuses  20  and the maintenance management apparatus  50  correctly what to do to solve the problem in which part.  
         [0111]     The following describes operations of the representative supervisory apparatus  20 A and the maintenance management apparatus  50  of the above described configuration according to the present embodiment.  
         [0112]     As exemplified by  FIG. 12 , each supervisory apparatus  20  collects the ID on general purpose bus  71  on the general purpose buses  31  and  32  at the initial startup (step  201 ), judges whether or not the apparatus itself is the representative supervisory apparatus  20 A, and if it is the representative supervisory apparatus  20 A then displays a management menu on the display  23  (step  203 ) for the operator to input the initial information in which information required for supervising the supervision object apparatus  10  (step  204 ), for communicating with the maintenance management apparatus  50 , et cetera, are included. The initial information is shared with the other supervisory apparatuses  20  and retained by each supervisory apparatus  20 .  
         [0113]     Then instructs all the other supervisory apparatuses  20  to perform connection confirmations with the maintenance center (i.e., maintenance management apparatus  50 ) (steps  205  and  206 ).  
         [0114]     Then, the maintenance management apparatus  50  finishes a center connection confirmation processing  300  for the apparatus itself and outputs a message on the display  23  instructing the operator  101  to look up the connection confirmation mail from the maintenance center on the apparatus installer terminal  100  (step  207 ).  
         [0115]     Then, if performs a mutual supervision processing  400  and a periodical connection processing  500 , which is respectively operated by each supervisory apparatus  20  independently in the background.  
         [0116]     Having found out not to be the representative supervisory apparatus  20 A in the above noted step  202 , a supervisory apparatus  20  becomes a terminal therefor and transitions to a terminal mode for displaying the information being notified by the representative supervisory apparatus  20 A by way of the general purpose buses  31  and  32  on the display  23  (step  208 ). That is, a similar window as shown by the display  23  on the representative supervisory apparatus  20 A will be shown by the display on the supervisory apparatus  20  for instance.  
         [0117]     Subsequently, waiting for the arrival of instruction by the representative supervisory apparatus  20 A for performing a connection confirmation with the maintenance center (step  209 ), each of supervisory apparatuses  20  performs a center connection confirmation processing  300 .  
         [0118]     As exemplified by the flow chart in  FIG. 13 , the above noted center connection confirmation processing  300  tries a connection confirmation (that is, transmission of a connection confirmation transmission data  41 ) with the maintenance management apparatus  50  at the maintenance center by way of the communication path  40   a  and the information network  40  (step  301 ) and, if a connection error is occurring (step  302 ), collects the network information in the communication path  40   a  and information network  40  with which the own apparatus is connected (step  303 ).  
         [0119]     Then, it judges whether or not the own apparatus is the representative supervisory apparatus  20 A (step  304 ), and, if it is the representative supervisory apparatus  20 A, transmits the network information of the own apparatus to a supervisory apparatus  20  of the next rank and request for a substitute report (i.e., transmission of a connection confirmation substitute transmission data  41 - 1  shown by  FIG. 9 ) to the maintenance center (step  305 ).  
         [0120]     On the other hand if its own apparatus is not a representative supervisory apparatus  20 A, it requests the representative supervisory apparatus  20 A for a substitute report (step  306 ).  
         [0121]     If there is no connection error detected in the step  302 , the processing ends.  
         [0122]     The flow chart shown by  FIG. 14  exemplifies the above noted mutual supervision processing  400  performed by each supervisory apparatus  20 .  
         [0123]     That is, as the mutual supervision processing  400  is started, a supervisory apparatus  20  judges whether or not the own apparatus is the representative supervisory apparatus  20 A (step  401 ), and, if it is not a representative supervisory apparatus  20 A, waits until a predefined time of periodical supervision (step  402 ), and sends out a prescribed supervision message to the representative supervisory apparatus  20 A by way of the general purpose buses  31  and  32  (step  403 ).  
         [0124]     Then it detects either a presence or absence of confirmation response back from the representative supervisory apparatus  20 A within a predetermined time (step  404 ) and, if there is no confirmation response, elects new representative supervisory apparatus  20 A based on an assumption of the representative supervisory apparatus  20 A having a problem (step  409 ) and goes back to the step  401 . If there is a confirmation response back from the representative supervisory apparatus  20 A in the step  404 , further detects either a presence or absence of error report from the representative supervisory apparatus  20 A (step  405 ) and, if there is an error report therefrom, a supervisory apparatus  20  in the next rank performs a substitute transmission of the error report for the representative supervisory apparatus  20 A to the maintenance center (step  408 ) by using an error report substitute transmission data  42 - 1 , followed by performing the processings in the step  409  and thereafter.  
         [0125]     If there is no error report from the representative supervisory apparatus  20 A in the step  406 , it tries to detect an error in its own apparatus (step  406 ) and, if there is an error detected, requests the representative supervisory apparatus  20 A for a substitute transmission of its own error to the maintenance center (by using an error report substitute transmission data  42 - 1 ) (step  407 ) and ends the processing by leaving from the supervisory operation for the supervision object apparatus  10 .  
         [0126]     That is, the representative supervisory apparatus  20 A, having received an error report about a supervisory apparatus  20 , records the error occurrence in the aforementioned supervisory apparatus  20  in the error flag  73  of the supervisory apparatus management table  70  and notifies the other supervisory apparatuses  20 .  
         [0127]     If there is no error detected in its own apparatus in the step  406 , then it repeats the processing in the step  406  and thereafter.  
         [0128]     If its own apparatus is judged to be the representative supervisory apparatus  20 A in the above noted step  401 , it supervises the receptions of prescribed supervision messages from the other supervisory apparatuses  20  (step  410 ) and, if there is such a message, then sends out a confirmation response back to the supervisory apparatus  20  from which the aforementioned message has been received (step  411 ) and resets the supervision timer for managing a threshold value of the receiving interval of supervision messages from the aforementioned supervisory apparatus  20  (step  412 ). That is, if there has been no supervision message received within the supervision timer from each supervisory apparatus  20  during the loop between the steps  410  and  413 , the representative supervisory apparatus  20 A regards the aforementioned supervisory apparatus  20  as erratic, records an error for the error flag  73  in the supervisory apparatus management table  70 , notifies all the supervisory apparatuses  20  that the aforementioned specific supervisory apparatus  20  is erratic so as to be recorded in the respective supervisory apparatus management tables  70  installed in all the supervisory apparatuses  20 , and removes the aforementioned specific supervisory apparatus  20  from a list of candidates for the future representative supervisory apparatus  20 A.  
         [0129]     If there is no supervision message received, it detects an error in the own apparatus (step  413 ) and, if no error, then goes back to the step  410 .  
         [0130]     If there is an error detected in its own apparatus in the step  413 , it transmits the error information to the other supervisory apparatus  20  by way of the general purpose buses  31  and  32 , requests for a substitute transmission by using an error report substitute transmission data  42 - 1  to the maintenance center (step  414 ) and ends the processing.  
         [0131]     Description will be given for the above noted periodical connection processing  500  while referring to the flow chart shown by  FIG. 15 . All the supervisory apparatuses  20  keep supervising the timing of their own periodical connection with the maintenance center by using a not-shown timing function, etcetera, (step  501 ), and, when the timing for a periodical connection arrives, create transmission information including the next scheduled periodical connection TOD (step  502 ), perform a periodical connection with the maintenance management apparatus  50  at the maintenance center (step  503 ) and, if the connection is successful, repeats trying to connect periodically in a predetermined time interval as shown in the steps  501  through  504 .  
         [0132]     If the periodical connection is failed in the step  504  (step  504 ), the supervisory apparatus  20  collects the error information relating to the communication path  40   a  and the information network  40  of its own apparatus, transmits it to another supervisory apparatus  20  by way of general purpose buses  31  and  32 , and requests for a substitute transmission to the maintenance center (step  505 ). The requested representative supervisory apparatus  20 A or supervisory apparatus  20  performs a substitute transmission to the maintenance center by using the error report substitute transmission data  42 - 1 .  
         [0133]     The given next is a description of an operation of the maintenance management apparatus  50  at the maintenance center while referring to the flow chart shown by  FIG. 16 .  
         [0134]     The maintenance management apparatus  50  supervises arrival of a connection confirmation transmission data  41  for a connection confirmation by a supervisory apparatus  20  by way of the information network  40  (step  601 ), and, when receiving the connection confirmation transmission data  41 , confirms a presence or absence of connection management table  90  corresponding to the supervision object apparatus ID  41   a  and creates one if there is not (step  602 ). If there is already a connection management table  90  corresponding to the supervision object apparatus ID  41   a  on the other hand, it performs the later described step  604  and thereafter.  
         [0135]     If then stores a time stamp indicating the received TOD in a timestamp  92  of the connection management table  90  (step  603 ). The time stamp will be used for the staring point for a later described T 1 .  
         [0136]     Then the maintenance management apparatus  50  stores the supervisory apparatus number  41   b  and the constitution information  41   d  (i.e., information indicating the very apparatus  20  being the “z”-th rank among the n number of the installed total supervisory apparatuses  20 ), et cetera, contained in the received connection confirmation transmission data  41  for the supervisory apparatus number  93  and the management information  95 , respectively, in the connection management table  90  and records a transmission completion in the connection flag  94  (step  604 ).  
         [0137]     And, when the connection confirmations are completed from all of the n number of supervisory apparatuses  20  installed for supervising the supervision object apparatus  10  corresponding to the specific supervision object apparatus ID  41   a  (step  605 ), the maintenance management apparatus  50  sends out one e-mail with the content such as the connection confirmation mail  43  as exemplified by  FIG. 17  based on the content of the connection management table  90  to the apparatus installer terminal  100  (step  606 ), thereby notifying the apparatus installer that the connection confirmations have been completed for all the n number of supervisory apparatuses  20  furnished for the supervision object apparatus  10  corresponding to a specific supervision object apparatus ID  41   a , and clears the connection management table  90  (step  607 ), followed by returning to the step  601 .  
         [0138]     If not completed in the step  605 , it continues to wait for receiving a confirmation until the maximum time T 1  (e.g., 10 minutes) from the TOD of the time stamp  92  (step  608 ) and, if a reception confirmation corresponding to the aforementioned supervision object apparatus ID  41   a  is received (step  609 ), it performs the step  604  and thereafter and registers the reception content in the connection management table  90 .  
         [0139]     If the connection confirmations from all the supervisory apparatuses  20  are not completed within the maximum time T 1 , it sends out one e-mail of a content such as the connection confirmation mail  44  shown by  FIG. 18  based on the content of the connection management table  90  at the time to the apparatus installer terminal  100  (step  610 ). The connection confirmation mail  44  also contains the content of substitute transmission so that the apparatus installer can firmly comprehend a failure in the supervisory apparatus  20 , et cetera.  
         [0140]     Then the maintenance management apparatus  50  waits for connection confirmations from the remaining supervisory apparatuses  20  until the maximum time T 2  (e.g., 24 hours) from the time of the time stamp  92  (step  611 ) and, if the connection confirmations from the remainder (step  612 ), registers the supervisory apparatus number  41   b , et cetera, in the connection management table  90  (step  613 ), and sends out one e-mail (i.e., connection confirmation mail  44 ) to the apparatus installer terminal  100  based on the content of the connection management table  90  at the time (step  614 ).  
         [0141]     The connection confirmation mail  44  also contains the content of substitute transmission so that the apparatus installer can firmly comprehend a failure in the supervisory apparatus  20 , et cetera.  
         [0142]     Then, judges whether or not the connection confirmations from all the supervisory apparatuses  20  have been received within the maximum time T 2  (step  615 ) and, if received, goes back to the step  607 , clears the connection management table  90  and goes back to the step  601 . If, however, not received from the all supervisory apparatuses in the step  615 , then goes back to the step  611 .  
         [0143]     As described thus far, connection confirmations with the maintenance center from a plurality of supervisory apparatuses  20  redundantly furnished for supervising the supervision object apparatus  10  required for a stable operation in a long period of time are automatically performed just by starting up one representative supervisory apparatus  20 A according to the present embodiment. This eliminates a necessity of the operator  101  working manually on the cumbersome operations such as an instruction for a connection confirmation or an input of the initial setting information for each of the supervisory apparatuses  20 , thus drastically simplifying connection confirmations, et cetera, for the supervisory apparatuses  20  at the time of starting up the information processing system.  
         [0144]     That is, it is possible to perform the connection confirmation operation quickly and correctly for the redundantly furnished supervisory apparatuses  20  in a remote maintenance by the maintenance center (i.e., maintenance management apparatus  50 ) by utilizing the information network  40 .  
         [0145]     Meanwhile, since a result of connection confirmation with the maintenance center for a plurality of supervisory apparatuses  20  being furnished for one supervision object apparatus  10  is notified from the maintenance center to the apparatus installer (i.e., the apparatus installer terminal  100 ) by compiling into one e-mail also containing error information such as a substitute transmission, the apparatus installer is able to comprehend a result of the connection confirmations for the plurality of supervisory apparatuses  20  being furnished for each supervision object apparatus  10  quickly while being freed from a cumbersome work such as looking up a number of e-mails individually for the number of the supervisory apparatuses  20  under management.  
         [0146]     Meanwhile, if there is a failure in the communication path for a specific supervisory apparatus  20 , a substitute notification of the failure to the maintenance center by another supervisory apparatus  20  and therefore a fault caused by the communication path can be averted by establishing a detour for the troubled supervisory apparatus  20 , thus enabling the redundantly furnished supervisory apparatuses  20  to function effectively, being unaffected by a failure in the information network  40  or the communication path  40   a . As a result, a stable operation of the supervision object apparatus  10  is made possible by the redundantly furnished supervisory apparatuses  20 .  
         [0147]     That is, in the remote maintenance of the redundantly furnished supervisory apparatuses  20  from the maintenance center by using the information network  40 , a stable operation is made possible by the redundantly furnished supervisory apparatuses  20  without being affected by a failure in the information network  40  and the communication path  40   a.    
         [0148]     Also, a mutual supervision between the representative supervisory apparatus  20 A and the supervisory apparatuses  20 , an automatic switching and a substitute notification of error information to the maintenance center empower the maintenance center and the apparatus installer to comprehend the redundantly furnished supervisory apparatuses  20  correctly and accomplish a stable operation of the supervision object apparatus  10  by a precise switching of the redundantly furnished supervisory apparatuses  20 .  
         [0149]     That is, in the remote maintenance of the redundantly furnished supervisory apparatuses  20  from the maintenance center by using the information network  40 , a stable operation is enabled by a correct switching of a failed supervisory apparatus  20 , without being affected by a failure in the information network  40  or the communication path  40   a.    
         [0150]     Meanwhile, since the maintenance management apparatus  50  at the maintenance center does not send a confirmation mail back to each supervisory apparatus  20 , there is no concern that such a confirmation mail to a supervisory apparatus  20  should be used for an illegitimate access to the supervisory apparatus  20 , hence enhancing the security for the supervision object apparatus  10  and supervisory apparatus  20 .  
         [0151]     It goes without saying that the present invention is not limited by the above described embodiment and rather can be changed within the scope of the concept of the invention.  
         [0152]     According to the present invention, a quick and correct connection confirmation operation in a short time for a remote maintenance of a redundantly furnished supervisory apparatus by using a network is enabled.  
         [0153]     Also, in a remote maintenance of a redundantly furnished supervisory apparatus by using a network, a stable operation is made possible by the redundantly furnished supervisory apparatus without being affected by a failure in the network.  
         [0154]     Furthermore, in a remote maintenance of a redundantly furnished supervisory apparatus by using a network, a stable operation is enabled by correctly switching a failed supervisory apparatus without being affected by a failure in the network.