US5983371A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active failure detection
Assignee: Stratus Technologies Bermuda Ltd
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Filing: 1997-07-11
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Granted: 1999-11-09
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Expires: 2017-07-11
Abstract
Abstract Failures in a fault-tolerant computer system which includes two or more input/output processors connected to a data communication system are detected by monitoring data communication. The computer system is able to detect failures associated with a primary input/output processor, as well as with a standby input/output processors, and is also able to discriminate between failures of the input/output processors and communication failures in the data communication network itself. In addition to using heartbeat-like transmissions, various other categories of data communication are also used to detect failures. The system is able to detect failures when the input/output processors are on a common network segment, allowing the processors to monitor identical data traffic, as well as when the processors are on different segments where, as a result of filtering behavior of network elements such as active hubs, the processors may not be able to monitor identical data traffic.
Inventors
- 👤 Christopher C. Lord
- 👤 David B. Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:06
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/0703; G06F11/0751; G06F11/0754; G06F11/0757; G06F11/16; G06F11/1629; G06F11/1633
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
127 words
A method for detecting a failure in a fault-tolerant computer system that includes a first input/output processor and a second input/output processor coupled to a data communication system, the method comprising the steps of: processing a first data communication at the first input/output processor; applying a timing criterion to a category of the first data communication processed by the first input/output processor to produce a first timing result; processing a second data communication at the second input/output processor; applying the timing criterion to the category of the second data communication processed by the second input/output processor to produce a second timing result; determining a relationship between the first timing result and the second timing result; and detecting whether a failure has occurred based on the determined relationship.
Claim 2
Independent Claim
127 words
A method for detecting a failure in a fault-tolerant computer system that includes a first input/output processor and a second input/output processor coupled to a data communication system, the method comprising the steps of: processing a first data communication at the first input/output processor; applying a timing criterion to a category of the first data communication processed by the first input/output processor to produce a first timing result; processing a second data communication at the second input/output processor; applying the timing criterion to the category of the second data communication processed by the second input/output processor to produce a second timing result; determining a relationship between the first timing result and the second timing result; and detecting whether a failure has occurred based on the determined relationship.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein the step of detecting whether the failure has occurred includes determining that a failure has occurred when a difference between the timing results exceeds a threshold value.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein the timing criterion is a time of last transmission or reception.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein the category of data communications includes messages originating from the first input/output processor.
Claim 6
Dependent Claim
33 words
The method of claim 4 wherein the category of data communications includes messages originating from the first input/output processor and directed to an address to which the second input/output processor is normally responsive.
Claim 7
Dependent Claim
31 words
The method of claim 4 wherein the category of data communications includes messages sent from the first input/output processor and directed through the data communication system to the second input/output processor.
Claim 8
Dependent Claim
18 words
The method of claim 1 wherein the category of data communications includes messages originating outside the computer system.
Claim 9
Dependent Claim
19 words
The method of claim 7 wherein the messages originate at a second computer coupled to the data communication system.
Claim 10
Dependent Claim
33 words
The method of claim 7 wherein the category of data communications includes messages originating outside the computer system and addressed to a group of systems of which the computer system is a member.
Claim 11
Dependent Claim
29 words
The method of claim 1 wherein the category of data communications includes messages originating from a third element of the computer system in data communication with the input/output processors.
Claim 12
Dependent Claim
140 words
The method of claim 1 further comprising the step of sending the first timing result from the first input/output processor to the second input/output processor wherein: the step of applying the timing criterion to the category of the first data communication processed by the first input/output processor includes applying the timing criterion to the category of the first data communication processed by the first input/output processor at the first input/output processor; the step of applying the timing criterion to the category of the second data communication processed by the second input/output processor includes applying the timing criterion to the category of the second data communication processed by the second input/output processor at the second input/output processor; and the step of determining a relationship between the timing results includes determining a difference between the timing results at the second input/output processor.
Claim 13
Dependent Claim
27 words
The method of claim 11 wherein the first timing result is sent over a dedicated communication channel between the first input/output processor and the second input/output processor.
Claim 14
Dependent Claim
146 words
The method of claim 1 wherein the step of applying the timing criterion to the category of the first data communication processed by the first input/output processor further includes applying a plurality of timing criteria to a corresponding plurality of categories of the first data communication processed by the first input/output processor to produce a first plurality of timing results; the step of applying the timing criterion to the category of the second data communication processed by the second input/output processor further includes applying the plurality of timing criteria to the corresponding plurality of categories of the second data communication processed by the second input/output processor to produce a second plurality of timing results; and the step of determining a relationship between the timing results further includes determining relationships between corresponding ones of the first plurality of timing results and the second plurality of timing results.
Claim 15
Dependent Claim
98 words
A fault-tolerant computer system coupled to a data communication system comprising: a first input/output processor configured to process a category of data communications and to apply a timing criterion to the category of data communications to produce a first timing result; and a second input/output processor configured to process the category of data communications and to apply a timing criterion to the category of data communications to produce a second timing result; wherein the computer system is configured to determine a relationship between the timing results and to determine whether a failure has occurred based on the relationship.
Claim 16
Dependent Claim
98 words
A fault-tolerant computer system coupled to a data communication system comprising: a first input/output processor configured to process a category of data communications and to apply a timing criterion to the category of data communications to produce a first timing result; and a second input/output processor configured to process the category of data communications and to apply a timing criterion to the category of data communications to produce a second timing result; wherein the computer system is configured to determine a relationship between the timing results and to determine whether a failure has occurred based on the relationship.
Claim 17
Dependent Claim
17 words
The system of claim 14 wherein the timing criterion is a time of last transmission or reception.
Claim 18
Dependent Claim
19 words
The system of claim 14 wherein the category of data communications includes messages originating from the first input/output processor.
Claim 19
Dependent Claim
31 words
The system of claim 16 wherein the category of data communications includes messages sent from the first input/output processor and directed through the data communication system to the second input/output processor.
Claim 20
Dependent Claim
33 words
The system of claim 16 wherein the category of data communications includes messages originating from the first input/output processor and directed to an address to which the second input/output processor is normally responsive.
Claim 21
Dependent Claim
18 words
The system of claim 14 wherein the category of data communications includes messages originating outside the fault-tolerant system.
Claim 22
Dependent Claim
19 words
The system of claim 19 wherein the messages originate at a second computer coupled to the data communication system.
Claim 23
Dependent Claim
33 words
The system of claim 19 wherein the category of data communications includes messages originating outside the fault-tolerant system and addressed to a group of systems of which the fault-tolerant system is a member.
Claim 24
Dependent Claim
35 words
The system of claim 14 further comprising a third element of the computer system in data communication with the input/output processors, and wherein the category of data communications includes messages originating from said third element.
Claim 25
Dependent Claim
71 words
The system of claim 14 further comprising: a dedicated communication channel coupling the first input/output processor and the second input/output processor, the communication channel being configured to send the first timing result from the first input/output processor to the second input/output processor; wherein the second input/output processor is configured to determine a difference between the timing results and to detect whether the failure has occurred when the difference exceeds a threshold.
Claim 26
Dependent Claim
116 words
The system of claim 14 wherein: the first input/output processor is further configured to apply a plurality of timing criteria to a corresponding plurality of categories of data communications processed by the first input/output processor to produce a first plurality of timing results; the second input/output processor is further configured to apply the plurality of timing criteria to the corresponding plurality of categories of data communications processed by the second input/output processor to produce a second plurality of timing results; and the computer system is further configured to determine a relationships between corresponding ones of the first and second plurality of timing results and to determine whether the failure has occurred based on the determined relationships.
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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) | 2002-11-08 | 2003-05-10 | 2003-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-08 | 2007-05-10 | 2007-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-08 | 2011-05-10 | 2011-11-09 | $7700.00 | Window Closed / Lapsed |