Method and system for error recovery for cascaded servers
First Claim
1. A method for error recovery in a client-server distributed processing system using cascaded servers, said distributed processing system comprising:
- an intermediate server; and
a successor server of said intermediate server, not in a processing loop with said intermediate server, the method comprising;
said intermediate server saving a copy of a request message sent to said successor server; and
if no done message has been received in a predetermined period of time, said intermediate server resending said request message to said successor server.
3 Assignments
0 Petitions
Accused Products
Abstract
An improved method for error recovery in client-server distributed processing systems using cascaded servers. The method adds an additional form of acknowledgement message from a server to its predecessor. This message is sent when the server has completed all its processing and has received an ACK message from its successor, indicating that its result has been successfully received by the successor. The predecessor server retains a copy of its results until it receives the done message, at which time the copy of the results is discarded. If a done message is not received by the time a timer has expired, indicating that a problem has occurred with a server or its communications, the predecessor server resends its stored results.
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Citations
30 Claims
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1. A method for error recovery in a client-server distributed processing system using cascaded servers, said distributed processing system comprising:
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an intermediate server; and a successor server of said intermediate server, not in a processing loop with said intermediate server, the method comprising; said intermediate server saving a copy of a request message sent to said successor server; and if no done message has been received in a predetermined period of time, said intermediate server resending said request message to said successor server. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for error recovery in a client-server distributed processing system using cascaded servers, said distributed processing system comprising:
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an intermediate server; a successor server of said intermediate server, not in a processing loop with said intermediate server; and a subsequent server of said intermediate server, the method comprising; said intermediate server saving a copy of a request message sent to said successor server; and if no done message has been received in a predetermined period of time, said intermediate server resending said request message to said successor server. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A computer system providing error recovery for a client-server distributed processing system having a cascade of servers, comprising:
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an intermediate server computer having; a program implementing a server function, a memory means for storing information, and a timing means for determining whether a predetermined period of time has elapsed; a successor server computer, not in a processing loop with said intermediate server computer said successor server computer being a successor of said intermediate server computer in said cascade of servers and not in a processing loop with said intermediate server computer; and a data communications system, comprising means for sending messages from said intermediate server computer to said successor server computer and for sending messages from said successor server computer to said intermediate server computer, wherein said intermediate server computer sends a request message to said successor server computer using said data communications system; and wherein said intermediate server computer saves said request message in said memory means of said intermediate server computer; and wherein said intermediate server computer starts said timing means when said request message is sent to said successor server computer; and wherein said intermediate server computer resends said request message to said successor server computer if said done message has not been received before said timing means has determined whether said predetermined period of time has elapsed. - View Dependent Claims (28)
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29. A computer system providing error recovery for a client-server distributed processing system having a cascade of servers, comprising:
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an intermediate server computer having; a program implementing a server function, a memory means for storing information, and a timing means for determining whether a predetermined period of time has elapsed; a successor server computer, not in a processing loop with said intermediate server computer said successor server computer being a successor of said intermediate server computer in said cascade of servers and not in a processing loop with said intermediate server computer; a subsequent server computer having a program implementing a server function, said subsequent server computer being a subsequent server in said cascade of servers to said intermediate server computer; and a data communications system, comprising means for sending messages from said intermediate server computer to said successor server computer and further comprising means for sending messages from said subsequent server computer to said intermediate server computer, wherein said intermediate server computer sends a request message to said successor server computer using said data communications system; and wherein said intermediate server computer saves said request message in said memory means of said intermediate server computer; and wherein said intermediate server computer starts said timing means when said request message is sent to said successor server computer; and wherein said intermediate server computer resends said request message to said successor server computer if said done message has not been received before said timing means has determined whether said predetermined period of time has elapsed. - View Dependent Claims (30)
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Specification