Parallel replication mechanism for state information produced by serialized processing

A system for parallel replication of state information of a first data processing unit in at least one second data processing unit, each of the at least one second data processing units having a replica of the state information of the first data processing unit, the system comprising:

• a first processing unit for processing an incoming request message for changing the state information in the first data processing unit;
• a respond unit for sending a response message to a sender of the incoming request message after confirming a receipt of a modification record for the incoming request message and modification records of all predecessors of the incoming request message by each of the at least one first storage subsystems;
• and
• at least one second processing unit for updating state information in the replica of each of the at least one second data processing units based on the modification records,
• wherein an incoming request message contains an indicator and a modification record contains the indicator assigned to a corresponding incoming request message and all corresponding changes applied to a set of records used to represent the state information of the first data processing unit.

A system for parallel replication of state information of a first data processing unit in at least one second data processing unit, each of the at least one second data processing units having a replica of the state information of the first data processing unit, the system comprising:

• means for processing an incoming request message for changing the state information in the first data processing unit;
• means for sending a response message to a sender of the incoming request message after confirming a receipt of a modification record for the incoming request message and modification records of all predecessors of the incoming request message by each of the at least one first storage subsystems;
• and
• means for updating state information in the replica of each of the at least one second data processing units based on the modification records,
• wherein an incoming request message contains an indicator and a modification record contains the indicator assigned to a corresponding incoming request message and all corresponding changes applied to a set of records used to represent the state information of the first data processing unit.

A method for replicating state information stored in a first data processing unit to a second data processing unit, whereby the state information is kept in a set of records, the method comprising, for each incoming request message

• requesting a change of the state information:
• receiving an incoming request message for changing the state information;
• assigning an indicator to the incoming request message representing the order in which the incoming request messages are processed;
• processing the incoming request message and updating the set of records in accordance with the result of the processing of the incoming request message;
• sending a modification record to a first storage subsystem containing the indicator assigned to the incoming request message and all changes applied to the set of records performed during processing of the incoming request message;
• checking acknowledge messages which have been received from the second data processing unit indicating a receipt of the sent modification records;
• and
• sending a response message as a reaction to an incoming request message to the respective sender for such incoming request messages, the modification record of which and the modification records of all its predecessors having been received by the first storage subsystem.

A system for replicating state information stored in a first data processing unit to a second data processing unit, whereby the state information is kept in a set of records, the system comprising:

• an input port for receiving an incoming request message for changing the state information;
• an initializing unit for assigning an indicator to the incoming request message representing the order in which the incoming request messages will be processed;
• a first processing unit for processing the incoming request message and updating the set of records in accordance with the result of the processing of the incoming request message;
• a communication unit for sending a modification record to a first storage subsystem containing the indicator assigned to the incoming request message and all changes applied to the set of records performed during processing of the incoming request message;
• a control unit for checking acknowledge messages which have been received from the first storage subsystem indicating a receipt of the sent modification records;
• and
• a respond unit for sending a response message as a reaction to an incoming request message to the respective sender for such incoming request messages, the modification record of which and the modification records of all its predecessors having been received by the second data processing unit.

A computer program product stored on a computer usable medium, comprising computer readable program means for causing a computer to perform a method for replicating state information stored in a first data processing unit to a second data processing unit, whereby the state information are kept in a set of records, the method comprising:

• receiving an incoming request message for changing the state information;
• assigning an indicator to the incoming request message representing the order in which the incoming request messages are processed;
• processing the incoming request message and updating the set of records in accordance with the result of the processing of the incoming request message;
• sending a modification record to a first storage subsystem containing the indicator assigned to the incoming request message and all changes applied to the set of records performed during processing of the incoming request message;
• checking acknowledge messages which have been received from the second data processing unit indicating a receipt of the sent modification records;
• and
• sending a response message as a reaction to an incoming request message to the respective sender for such incoming request messages the modification record of which and the modification records of all its predecessors have been received by the first storage subsystem.