Redundant message processing system featuring reception server controlling communication between client and server process, and stand-by server retransmitting message with information indicating the message being a retransmitted message

A message communication processing system including a stand-by system, said message communication processing system being in a distributed processing system implemented by a computer network including first, second, and third interconnected computers, said message communication processing system comprising:

• client process means for issuing a message including a demand and implemented by the first computer of the computer network;
• processing server means for processing the message and implemented by the second computer of the computer network;
• and
• reception server means for controlling communication between said client process means and said processing server means and implemented by the second computer of the computer network or by the third computer of the computer network, said reception server means including demand discrimination means for distinguishing between a first demand used only for referencing and not updating one of a medium and a state of a source, and a second demand used for referencing and updating a process associated with a change of the state of the source, wherein
• said reception server means identifies said processing server means which becomes a service provider for a service demand, and demands provision of the service demand from the processing server means,
• said reception server means adds an identifier and a reception re-transmission count to the message issued from the client process means forming a process message to be transmitted to the processing server means, and
• said processing server means stores the identifier and first and second re-transmission counts as change over information used for a stand-by system, said processing server means performing a comparison between said first and second re-transmission counts and said reception re-transmission count to determine whether said message is a re-transmitted message or a redundantly transmitted message.

A recovery method in a distributed processing system implemented by a computer network, transmitting a first message issued by a client process after a software problem has been experienced, said recovery method comprising the steps of:

• (a) receiving the first message from the client process and inserting in the first message a message identifier, and first and second re-transmission counts forming a second message using a reception server;
• (b) identifying a process server using the reception server;
• (c) transmitting the second message to the process server without maintaining storage of the first and second messages in the reception server;
• and
• (d) processing the second message and determining whether the second message is one of a new, redundant and retransmitted message using the message identifier and the first and second re-transmission counts using the process server.

A message communication processing system in a distributed processing system implemented by a computer network including first, second, and third interconnected computers, said message communication processing system comprising:

• client process means for issuing a message including one of a first type demand and a second type demand, and implemented by the first computer of the computer network;
• processing server means for processing the message and implemented by the second computer of the computer network;
• and
• reception server means for controlling communication between said client process means and said processing server means and implemented by the second computer of the computer network or by the third computer of the computer network, said reception server means including demand discrimination means for distinguishing between said first type demand and said second type demand, wherein
• said processing server means comprises:
• discrimination stage means for determining whether the processing of the message transmitted from the client process means has already been completed,
• demand processing stage means for performing a demand process for the message received from the client process means when said discrimination stage means determines that the processing of the message transmitted from the client processing means is not completed,
• writing stage means for writing the results of the demand process performed in said demand processing stage to a non-volatile memory, and
• issuing stage means for issuing a first notice that the message processing has already been completed as determined by said discrimination stage means and a second notice that the demand process performed by the demand processing stage means is normally completed when said discrimination stage means determines that the processing is not completed, and
• said client process means determines that the message communication is normal when a re-transmission process for the message is performed and said first notice that the process has already been performed is issued.

A message communication processing system, including a stand-by system, in a distributed processing system implemented by a computer network including first, second, and third interconnected computers, said message communication processing system comprising:

• client process means for issuing a message including one of a first type demand and a second type demand, and implemented by the first computer of the computer network;
• processing server means for processing the message and implemented by the second computer of the computer network;
• and
• reception server means for controlling communication between said client process means and said processing server means and implemented by the second computer of the computer network or by the third computer of the computer network, said reception server means including demand discrimination means for distinguishing between said first type demand and said second type demand, wherein
• said reception server means identifies said processing server means which becomes a service provider for a service demand, and demands provision of the service demand from the processing server means,
• said reception server means adds an identifier and a reception re-transmission count to the message issued from the client process means forming a process message to be transmitted to the processing server means, and
• said processing server means stores the identifier and first and second re-transmission counts as change over information used for the stand-by system, said processing server means performing a comparison between said first and second re-transmission counts and said reception re-transmission count to determine whether said message is a re-transmitted message or a redundantly transmitted message.