Distributed consensus method, distributed system and distributed consensus program

A distributed system comprising:

• a plurality of server apparatuses coupled to one or more client apparatuses via a network;
• and
• an auxiliary consensus device, which is an auxiliary device that assists in reaching consensus in an event of a failure in response to a request from the server apparatus, wherein
• the plurality of server apparatuses perform data consensus processing by operating data according to a predetermined distributed consensus algorithm, and
• auxiliary consensus decided value is caused to take precedence over a decided value of the distributed consensus algorithm under conditions under which an auxiliary consensus decided value decided by the auxiliary consensus device and the decided value decided by the distributed consensus algorithm can conflict with each other,
• wherein the auxiliary consensus device decides whether or not a request with an identical identification number with the auxiliary consensus decided value has already been received from one of the server apparatuses,
• wherein, if the request with the identical identification number with the auxiliary consensus decided value has already been received from the one of the server apparatuses, then the auxiliary consensus device transmits to a source apparatus of the server apparatuses, the auxiliary consensus decided value with the identification number identical to that of the received auxiliary consensus request,
• wherein, if the request with the identical identification number with the auxiliary consensus decided value has not already been received from the one of the server apparatuses, then the auxiliary consensus device considers data included in the received auxiliary consensus request to be the auxiliary consensus decided value for the identification number, saves the data, and transmits the data to all the server apparatuses,
• wherein, each of the plurality of server apparatuses comprises a first decision node that receives/transmits the data from/to the client apparatus and a second decision node that performs aggregation of the data and the consensus processing,
• wherein, the client apparatus puts data to all the first decision nodes,
• wherein, each first decision node transmits data to all the second decision nodes,
• wherein, the second decision node aggregates data received from the first decision node, executes the consensus processing,
• wherein, the second decision node decides whether or not the data in a decision matrix is all the data and is the same as a priority value set in advance,
• wherein, if the data in the decision matrix is not all the data and is not the same as the priority value, then second decision node transmits the auxiliary consensus request to the auxiliary consensus device,
• wherein, the second decision node receives the auxiliary consensus decided value from the auxiliary consensus device, the second decision node stores the auxiliary consensus decided value as a confirmed value, and
• wherein, if the data in the decision matrix is all the data and is the same as the priority value, then second decision node determines that consensus is achieved without transmitting the auxiliary consensus request to the auxiliary consensus device, stores the data from the decision matrix as the confirmed value, and completes a consensus with the identification number.

A non-transitory machine readable storage medium encoded with medium-readable instructions for a distributed consensus program that performs data consensus processing on a distributed system that couples one or more client apparatuses and a plurality of server apparatuses via a network, the program causing each server apparatus to execute:

• a step of performing data operation according to a predetermined distributed consensus algorithm;
• a step of sending a request to an auxiliary consensus device, which is an auxiliary device that assists in reaching consensus in an event of a failure and deciding an auxiliary consensus decided value;
• and
• a step of causing the auxiliary consensus decided value to take precedence over the decided value of the distributed consensus algorithm under conditions under which the auxiliary consensus decided value decided by the auxiliary consensus device and the decided value decided according to the distributed consensus algorithm can conflict with each other,
• wherein the auxiliary consensus device decides whether or not a request with an identical identification number with the auxiliary consensus decided value has already been received from one of the server apparatuses,
• wherein, if the request with the identical identification number with the auxiliary consensus decided value has already been received from the one of the server apparatuses, then the auxiliary consensus device transmits to a source apparatus of the server apparatuses, the auxiliary consensus decided value with the identification number identical to that of the received auxiliary consensus request,
• wherein, if the request with the identical identification number with the auxiliary consensus decided value has not already been received from the one of the server apparatuses, then the auxiliary consensus device considers data included in the received auxiliary consensus request to be the auxiliary consensus decided value for the identification number, saves the data, and transmits the data to all the server apparatuses,
• wherein, each of the plurality of server apparatuses comprises a first decision node that receives/transmits the data from/to the client apparatus and a second decision node that performs aggregation of the data and the consensus processing,
• wherein, the client apparatus puts data to all the first decision nodes,
• wherein, each first decision node transmits data to all the second decision nodes,
• wherein, the second decision node aggregates data received from the first decision node, executes the consensus processing,
• wherein, the second decision node decides whether or not the data in a decision matrix is all the data and is the same as a priority value set in advance,
• wherein, if the data in the decision matrix is not all the data and is not the same as the priority value, then second decision node transmits the auxiliary consensus request to the auxiliary consensus device,
• wherein, the second decision node receives the auxiliary consensus decided value from the auxiliary consensus device, the second decision node stores the auxiliary consensus decided value as a confirmed value, and
• wherein, if the data in the decision matrix is all the data and is the same as the priority value, then second decision node determines that consensus is achieved without transmitting the auxiliary consensus request to the auxiliary consensus device, stores the data from the decision matrix as the confirmed value, and completes a consensus with the identification number.