US6334196B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Estimator program for estimating the availability of an application program that runs in a cluster of at least two computers
Assignee: Unisys Corp
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Filing: 1999-02-12
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Granted: 2001-12-25
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Expires: 2019-02-12
Abstract
Abstract An estimator program is disclosed which performs method steps for estimating the availability of an application program that runs on any computer in a cluster of at least two computers. By the availability of an application program is herein meant the probability that at any particular time instant, at least one of the computers in the cluster will actually be servicing requests from external workstations to use the application program. In one embodiment, the estimator program begins by receiving input parameters which include 1) multiple downtime periods for each computer in the cluster that occur at respective frequencies due to various downtime sources, and 2) an application failover time period for switching the running of the application program from any one computer to another. From those input parameters, the estimator program estimates first and second annual stoppage times, and then determines the availability of the application program on the cluster from the sum of the first and second annual stoppage times.
Inventors
- 👤 Lev Smorodinsky
- 👤 Norman Roy Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:11
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/008
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
216 words
A program storage device embodying an estimator program that performs method steps for estimating the availability of an application program that runs on any computer in a cluster of at least two computers; said method including the steps of: receiving input parameters which include multiple downtime periods for each computer in said cluster that occur at respective frequencies due to various downtime period sources, and include an application failover time period for switching the running of said application program from any one of said computers to another; generating from said input parameters, a single computer virtual downtime period and a single computer virtual time between stops and a single computer virtual stoppage rate; estimating a first annual stoppage time for said application program, due solely to concurrent stoppage of all of said computers, as a function of the ratio of said single computer virtual downtime period over said single computer virtual time between stops; estimating a second annual stoppage time for said application program, due solely to switching the running of said application program from one computer to another as a function of said single virtual stoppage rate and said application failover time period; and, determining said availability of said application program on said cluster from the sum of said first and second annual stoppage times.
Claim 2
Dependent Claim
216 words
A program storage device embodying an estimator program that performs method steps for estimating the availability of an application program that runs on any computer in a cluster of at least two computers; said method including the steps of: receiving input parameters which include multiple downtime periods for each computer in said cluster that occur at respective frequencies due to various downtime period sources, and include an application failover time period for switching the running of said application program from any one of said computers to another; generating from said input parameters, a single computer virtual downtime period and a single computer virtual time between stops and a single computer virtual stoppage rate; estimating a first annual stoppage time for said application program, due solely to concurrent stoppage of all of said computers, as a function of the ratio of said single computer virtual downtime period over said single computer virtual time between stops; estimating a second annual stoppage time for said application program, due solely to switching the running of said application program from one computer to another as a function of said single virtual stoppage rate and said application failover time period; and, determining said availability of said application program on said cluster from the sum of said first and second annual stoppage times.
Claim 3
Dependent Claim
32 words
A method according to claim 1 wherein said first annual stoppage time for said application is estimated as two times the square of said ratio times the number of hours per year.
Claim 4
Dependent Claim
32 words
A method according to claim 1 wherein said first annual stoppage time for said application is estimated as six times the cube of said ratio times the number of hours per year.
Claim 5
Dependent Claim
35 words
A method according to claim 1 wherein said first annual stoppage time for said application is estimated as N factorial times said ratio raised to the Nth power times the number of hours per year.
Claim 6
Dependent Claim
29 words
A method according to claim 1 wherein said second annual stoppage time for said application is estimated as said single virtual stoppage rate times said application failover time period.
Claim 7
Dependent Claim
50 words
A method according to claim 1 wherein said single virtual downtime period is generated as the sum of multiple products divided by said single virtual stoppage rate, and where each product is formed by multiplying one of said multiple downtimes periods for each computer with its respective frequency of occurrence.
Claim 8
Dependent Claim
30 words
A method according to claim 1 wherein said single virtual stoppage rate is generated as the sum of said respective frequencies of occurrence for each of said multiple downtime periods.
Claim 9
Dependent Claim
61 words
A method according to claim 1 wherein said multiple downtime periods that occur at respective frequencies in each computer of said cluster include an average hardware stoppage time period that occurs at a first frequency, an average software stoppage time period that occurs at a second frequency, and an average system administrator stoppage time period that occurs at a third frequency.
Claim 10
Dependent Claim
55 words
A method according to claim 1 wherein said input parameters include a relatively short downtime period which occurs at a relatively high frequency that is due to defects in said application programs, and include a relatively long downtime period which occurs at a relatively low frequency that is due to hardware failures in said cluster.
Claim 11
Dependent Claim
36 words
A method according to claim 9 wherein said relatively high frequency of occurrence has a range of one per 1-1000 hours, and said relatively low frequency of occurrence has a range of one per 1,000-20,000 hours.
Claim 12
Dependent Claim
29 words
A method according to claim 9 wherein said relatively short downtime period has a range of 1-60 minutes, and said relatively long downtime period has range of 1-60 hours.
Claim 13
Dependent Claim
17 words
A method according to claim 1 wherein said failover time period has a range of 0.001-60 minutes.
Claim 14
Dependent Claim
117 words
A program storage device embodying an estimator program that performs method steps for estimating the availability of an application program that runs on any computer in a cluster of at least two computers; said method including the steps of: receiving input parameters which include multiple average downtime periods for each computer in said cluster that occur at respective frequencies due to various downtime period sources; generating from said input parameters, a single computer virtual downtime period and a single computer virtual time between stops; and, estimating a probability of concurrent stoppage for all of said computers, as a function of the ratio of said single computer virtual downtime period over said single computer virtual time between stops.
Claim 15
Dependent Claim
117 words
A program storage device embodying an estimator program that performs method steps for estimating the availability of an application program that runs on any computer in a cluster of at least two computers; said method including the steps of: receiving input parameters which include multiple average downtime periods for each computer in said cluster that occur at respective frequencies due to various downtime period sources; generating from said input parameters, a single computer virtual downtime period and a single computer virtual time between stops; and, estimating a probability of concurrent stoppage for all of said computers, as a function of the ratio of said single computer virtual downtime period over said single computer virtual time between stops.
Claim 16
Dependent Claim
22 words
A method according to claim 13 wherein said probability of concurrent stoppage is estimated as two times the square of said ratio.
Claim 17
Dependent Claim
48 words
A method according to claim 14 wherein said single virtual downtime period is generated as the sum of multiple products divided by the sum of said respective frequencies; where each product is formed by multiplying one of said multiple downtimes periods for each computer with its respective frequency.
Claim 18
Dependent Claim
22 words
A method according to claim 13 wherein said probability of concurrent stoppage is estimated as six times the cube of said ratio.
Claim 19
Dependent Claim
48 words
A method according to claim 16 wherein said single virtual downtime period is generated as the sum of multiple products divided by the sum of said respective frequencies; where each product is formed by multiplying one of said multiple downtimes periods for each computer with its respective frequency.
Claim 20
Dependent Claim
32 words
A method according to claim 13 wherein said probability of concurrent stoppage is estimated as N factorial times said ratio to the Nth power, where N is an integer greater than three.
Claim 21
Dependent Claim
48 words
A method according to claim 18 wherein said single virtual downtime period is generated as the sum of multiple products divided by the sum of said respective frequencies; where each product is formed by multiplying one of said multiple downtimes periods for each computer with its respective frequency.
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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) | 2004-12-24 | 2005-06-25 | 2005-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-12-24 | 2009-06-25 | 2009-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-12-24 | 2013-06-25 | 2013-12-25 | $7700.00 | Window Closed / Lapsed |