Server decision method and device thereof

A server decision device which decides the existence of an only server to operate a specific task within a plurality of servers connected via a network, comprising:

• a classifying unit for classifying each of said plurality of servers into a main server candidate group capable of operating the specific task, a sub-server candidate group capable of operating a back-up task of the specific task, and an out-of-candidate server group which is excluded from operating the specific task and the back-up task;
• a main server processing unit to which each of the servers in said main server candidate group presents public relations information necessary for the election judgment of a main server, each of said servers running as a candidate at a boot time and, at the same time, each of said servers compares its respective public relation information to that of other servers and, when it is determined that a particular server is not a desirable candidate, presentation of said particular server's public relations information is stopped and its candidacy is withdrawn;
• and
• a sub-server processing unit to which each of the servers in said sub-server candidate node group presents public relations information necessary for the election judgment of a sub-server to all the servers, each of said sub-server servers running as a candidate at a boot time and, at the same time, each of said sub-server servers compares its respective public relations information to that of other servers and, when it is determined that a particular sub-server server is not a desirable candidate, presentation of said particular sub-server server's public relations information is stopped and its candidacy is withdrawn,
• wherein a main server candidacy processing unit of said main server and a sub-server candidacy processing unit of said sub-server are selected at said boot time and periodically report an operation of the specific task to all other servers and assert a right of said main server or said sub-server at an operation starting time after boot and, when a same report asserting said right of said main server or said sub-server is received from other servers, said candidacy processing units recognize a duplicate starting of a plurality of said main servers or said sub-servers and present public relations information of said asserted main server or sub-server to all other servers and, at the same time, compare said main server or sub-server public relations information to that of other servers and, when a particular main server or sub-server is determined to not be desirable candidate, presentation of said particular main server or sub-server's public relations information is stopped and its candidacy is withdrawn.