US5157663A
Expired / Lapsed
US
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Fault tolerant computer system
Assignee: Micro Focus Software Inc
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Filing: 1990-09-24
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Granted: 1992-10-20
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Expires: 2010-09-24
Abstract
Abstract A method and apparatus for providing a fault-tolerant backup system such that if there is a failure of a primary processing system, a replicated system can take over without interruption. The invention provides a software solution for providing a backup system. Two servers are provided, a primary and secondary server. The two servers are connected via a communications channel. The servers have associated with them an operating system. The present invention divides this operating system into two "engines." An I/O engine is responsible for handling and receiving all data and asynchronous events on the system. The I/O engine controls and interfaces with physical devices and device drivers. The operating system (OS) engine is used to operate on data received from the I/O engine. All events or data which can change the state of the operating system are channeled through the I/O engine and converted to a message format. The I/O engine on the two servers coordinate with each other and provide the same sequence of messages to the OS engines. The messages are provided to a message queue accessed by the OS engine. Therefore, regardless of the timing of the events, (i.e., asynchronous events), the OS engine receives all events sequentially through a continuous sequential stream of input data. As a result, the OS engine is a finite state automata with a one-dimensional input "view" of the rest of the system and the state of the OS engines on both primary and secondary servers will converge.
Inventors
- 👤 Drew Major
- 👤 Kyle Powell
- 👤 Dale Neibaur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:47
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/16; G06F11/1675; G06F11/1687; G06F11/14; G06F11/1479; G06F11/1482; G06F11/20; G06F11/2053; G06F11/2056; G06F11/2071; G06F11/2076; G06F11/1658; G06F11/202; G06F11/2038; G06F11/2048
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
183 words
A method for providing a fault tolerant computer system comprising the steps of: providing a first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; providing a second processing means, said second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; determining a state of said first processing means and providing said state to said second processing means; defining an operation that can change said state of said first OS engine as an event; providing a plurality of events to said first I/O engine and converting each of said events into a message; providing said message to a first message queue in said first OS engine and to a second message queue in said second OS engine; executing said message in said first OS engine and said second OS engine; switching said computer system operation to said second processing means upon failure of said first processing means, such that no loss of operation of said computer system occurs during said switchover.
Claim 2
Independent Claim
183 words
A method for providing a fault tolerant computer system comprising the steps of: providing a first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; providing a second processing means, said second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; determining a state of said first processing means and providing said state to said second processing means; defining an operation that can change said state of said first OS engine as an event; providing a plurality of events to said first I/O engine and converting each of said events into a message; providing said message to a first message queue in said first OS engine and to a second message queue in said second OS engine; executing said message in said first OS engine and said second OS engine; switching said computer system operation to said second processing means upon failure of said first processing means, such that no loss of operation of said computer system occurs during said switchover.
Claim 3
Dependent Claim
59 words
The method of claim 1 further including the steps of: providing each event to said second I/O engine when said first processing means does not operate; converting each of said events to a message in said second I/O engine; providing said message to said second message queue in said second OS engine for execution by said second OS engine.
Claim 4
Dependent Claim
74 words
The method of claim 1 wherein said steps of determining the state of said first processing means and providing said state to said second processing means comprises the steps of: executing in said first OS engine any messages available to said first OS engine until said first OS engine has achieved a stable state; and, transferring a memory image of said first OS engine through said first I/O engine to said second processing means.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said first processing means comprises at least one processor.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said second processing means comprises at least one processor.
Claim 7
Dependent Claim
58 words
The method of claim 1 further including the steps of: generating a request in said OS engine, said request for accomplishing an input/output operation; providing said request to a first request queue in said first I/O engine for execution by said first I/O engine; generating a reply to said first OS engine to indicate execution of said request.
Claim 8
Dependent Claim
10 words
The method of claim 1 wherein said event is asynchronous.
Claim 9
Dependent Claim
163 words
A fault tolerant computer system comprising: first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; said first I/O engine coupled to said second I/O engine on a first bus; said first I/O engine including a converting means for converting operations that can change said state of said first OS engine into a message; said first I/O engine for providing said message to a first message queue in said first OS engine and to a second message queue in said second OS engine; said first OS engine and said second OS engine including means for executing said message; means for switching said computer system operation to said second OS engine upon failure of said first processing means such that no loss of operation of said computer system occurs during said switchover.
Claim 10
Dependent Claim
163 words
A fault tolerant computer system comprising: first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; said first I/O engine coupled to said second I/O engine on a first bus; said first I/O engine including a converting means for converting operations that can change said state of said first OS engine into a message; said first I/O engine for providing said message to a first message queue in said first OS engine and to a second message queue in said second OS engine; said first OS engine and said second OS engine including means for executing said message; means for switching said computer system operation to said second OS engine upon failure of said first processing means such that no loss of operation of said computer system occurs during said switchover.
Claim 11
Dependent Claim
16 words
The computer system of claim 8 wherein said first processing means comprises at least one processor.
Claim 12
Dependent Claim
16 words
The computer system of claim 8 wherein said second processing means comprises at least one processor.
Claim 13
Dependent Claim
35 words
The computer system of claim 8 further including a first storage means coupled to said first processing means, said first storage means storing a memory image corresponding to said state of said first OS engine.
Claim 14
Dependent Claim
35 words
The computer system of claim 11 further including a second storage means coupled to said second processing means, said second storage means storing a memory image corresponding to said state of said second OS engine.
Claim 15
Dependent Claim
19 words
The computer system of claim 8 wherein said first OS engine controls execution of instructions of said computer system.
Claim 16
Dependent Claim
28 words
The computer system of claim 13 wherein said second OS engine controls execution of instructions of said computer system when said first OS engine cannot execute said instructions.
Claim 17
Dependent Claim
17 words
The computer system of claim 8 wherein said I/O engine controls communication with input and output devices.
Claim 18
Dependent Claim
14 words
The computer system of claim 8 wherein said message comprises synchronous and asynchronous events.
Claim 19
Independent Claim
173 words
A method for providing a fault tolerant computer system comprising the steps of: providing a first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; providing a second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; determining a state of said first processing means and providing said state to said second processing means; defining an operation that can change said state of said first OS engine as an event; providing a plurality of events to said first I/O engine and serializing said events into an event sequence; providing successive events in said event sequence to said first OS engine and to said second OS engine; executing said successive events in said first OS engine and said second OS engine, switching said computer system operation to said second processing means upon failure of said first processing means, such that no loss of operation to said computer system occurs during said switchover.
Claim 20
Independent Claim
173 words
A method for providing a fault tolerant computer system comprising the steps of: providing a first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; providing a second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; determining a state of said first processing means and providing said state to said second processing means; defining an operation that can change said state of said first OS engine as an event; providing a plurality of events to said first I/O engine and serializing said events into an event sequence; providing successive events in said event sequence to said first OS engine and to said second OS engine; executing said successive events in said first OS engine and said second OS engine, switching said computer system operation to said second processing means upon failure of said first processing means, such that no loss of operation to said computer system occurs during said switchover.
Claim 21
Dependent Claim
57 words
The method of claim 17 further including the steps of: providing each event to said second I/O engine when said first processing means does not operate; serializing said events into an event sequence in said second I/O engine; providing successive events of said event sequence to said second OS engine for execution by said second OS engine.
Claim 22
Dependent Claim
75 words
The method of claim 17 wherein said step of determining the state of said first processing means and providing said state to said second processing means comprises the steps of: executing in said first OS engine any successive events available to said first OS engine until said first OS engine has achieved a stable state; and, transferring a memory image of said first OS engine through said first I/O engine to said second processing means.
Claim 23
Dependent Claim
15 words
The method of claim 17 wherein said first processing means comprises at least one processor.
Claim 24
Dependent Claim
15 words
The method of claim 17 wherein said second processing means comprises at least one processor.
Claim 25
Dependent Claim
58 words
The method of claim 17 further including the steps of: generating a request in said OS engine, said request for accomplishing an input/output operation; providing said request to a first request queue in said first I/O engine for execution by said first I/O engine; generating a reply to said first OS engine to indicate execution of said request.
Claim 26
Dependent Claim
12 words
The method of claim 17 wherein said plurality of events are asynchronous.
Claim 27
Dependent Claim
156 words
A fault tolerant computer system comprising: first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; said first I/O engine coupled to said second I/O engine on a first bus; said first I/O engine including a converting means for converting operations that can change said state of said first OS engine into an operation sequence; said first I/O engine for providing said operations in sequence to said first OS engine and to said second OS engine; said first OS engine and said second OS engine including means for executing said operations; means for switching said computer system operation to said second OS engine upon failure of said first processing means such that no loss of operation of said computer system occurs during said switchover.
Claim 28
Dependent Claim
156 words
A fault tolerant computer system comprising: first processing means for operation of said computer system, said first processing means comprising a first operating system (OS) engine and a first input/output (I/O) engine; second processing means comprising a second operating system (OS) engine and a second input/output (I/O) engine; said first I/O engine coupled to said second I/O engine on a first bus; said first I/O engine including a converting means for converting operations that can change said state of said first OS engine into an operation sequence; said first I/O engine for providing said operations in sequence to said first OS engine and to said second OS engine; said first OS engine and said second OS engine including means for executing said operations; means for switching said computer system operation to said second OS engine upon failure of said first processing means such that no loss of operation of said computer system occurs during said switchover.
Claim 29
Dependent Claim
16 words
The computer system of claim 24 wherein said first processing means comprises at least one processor.
Claim 30
Dependent Claim
16 words
The computer system of claim 24 wherein said second processing means comprises at least one processor.
Claim 31
Dependent Claim
35 words
The computer system of claim 24 further including a first storage means coupled to said first processing means, said first storage means storing a memory image corresponding to said state of said first OS engine.
Claim 32
Dependent Claim
35 words
The computer system of claim 27 further including a second storage means coupled to said second processing means, said second storage means storing a memory image corresponding to said state of said second OS engine.
Claim 33
Dependent Claim
19 words
The computer system of claim 24 wherein said first OS engine controls execution of instructions of said computer system.
Claim 34
Dependent Claim
28 words
The computer system of claim 29 wherein said second OS engine controls execution of instructions of said computer system when said first OS engine cannot execute said instructions.
Claim 35
Dependent Claim
17 words
The computer system of claim 24 wherein said I/O engine controls communication with input and output devices.
Claim 36
Dependent Claim
14 words
The computer system of claim 24 wherein said sequence comprises synchronous and asynchronous operations.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-20 | 1996-04-20 | 1996-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-20 | 2000-04-20 | 2000-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-20 | 2004-04-20 | 2004-10-20 | $7700.00 | Window Closed / Lapsed |