US4887204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for accessing remote files in a distributed networking environment
Assignee: International Business Machines Corp
•
Filing: 1987-02-13
•
Granted: 1989-12-12
•
Expires: 2007-02-13
Abstract
Abstract A distrbuted services program installed on each of a plurality of data processing systems in a network allows the processors to access data files distrbuted across the various nodes of the network. To reduce the network traffic overhead when files at other nodes are accessed, and to preserve the file system semantics, i.e. the file integrity, the accessing of the various files are managed by file synchronization modes. A file is given a first synchronization mode if a file is open at only one node for either read or write access. A file is given a second synchronization mode if a file is opened for read only access at any node. A file is given a third synchronization mode if the file is open for read access in more than one node, and at least one node has the file open for write access. If a file is in either the first or second synchronization mode, the client node, which is the node accessing the file, uses a client cache within its operating system store the file. All read and writes are then sent to this cache. If a file is in the third mode, all read and write requests must go to the server node where the file resides. The node accessing the file does not use the cache in its operating system to access the file data during this third mode.
Inventors
- 👤 Donavon W. Johnson
- 👤 Grover H. Neuman
- 👤 Charles H. Sauer
- 👤 Amal A. Shaheen-Gouda
- 👤 Todd A. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:36
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/02; G06F12/08; G06F12/0802; G06F12/0806; G06F12/0813; G06F16/00; G06F16/10; G06F16/17; G06F16/172; G06F16/18; G06F16/182; Y; Y10; Y10S; Y10S707/00; Y10S707/99931; Y10S707/99938
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
112 words
A system for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said system comprising: at least one client cache in the at least one client processing system caching blocks of the file at the at least one client node; means for generating a file synchronization mode for the file, said file synchronization mode being dependent upon how many and which processes in the network have the file open, and whether the file is open for read only or write access; and means for managing said at least one client cache through the file synchronization mode.
Claim 2
Independent Claim
112 words
A system for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said system comprising: at least one client cache in the at least one client processing system caching blocks of the file at the at least one client node; means for generating a file synchronization mode for the file, said file synchronization mode being dependent upon how many and which processes in the network have the file open, and whether the file is open for read only or write access; and means for managing said at least one client cache through the file synchronization mode.
Claim 3
Dependent Claim
39 words
The system as in claim 1 wherein the file synchronization mode is a first file mode if all opens for the file are at only one client node, and at least one of the opens is for write access.
Claim 4
Dependent Claim
25 words
The system of claim 1 wherein the file synchronization mode is a second file mode if the file is only open for read only access.
Claim 5
Dependent Claim
47 words
The system of claim 1 wherein the file synchronization mode is a third file mode if the file is open by processes executing at more than one node, and the file is open for write access by at least one process executing in at least one node.
Claim 6
Dependent Claim
26 words
The system of claim 1 wherein the file synchronization mode is a third file mode if a device containing the file is open for write access.
Claim 7
Dependent Claim
23 words
The system of claim 2 or 3 wherein the at least one client cache is accessed for a read access to the file.
Claim 8
Dependent Claim
21 words
The system of claim 2 wherein the at least one client cache is accessed for a write access to the file.
Claim 9
Dependent Claim
21 words
The system of claim 4 or 5 wherein the server processing system is accessed for a read access to the file.
Claim 10
Dependent Claim
21 words
The system of claim 4 or 5 wherein the server processing system is accessed for a write access to the file.
Claim 11
Independent Claim
124 words
A method, in a data processing system having at least one node, for accessing a file residing in a server processing system at a server node by at least one client processing system at least on client node, said method comprising the steps of: generating at least one synchronization mode for the file, said synchronization mode being dependent upon how many and which processes in the network have the file open, and whether the file is open for read only or write access; and caching the file at the at least one client node in at least one client cache as determined by said generated synchronization mode; and managing access to said at least one client cache as determined by said generated synchronization mode.
Claim 12
Independent Claim
124 words
A method, in a data processing system having at least one node, for accessing a file residing in a server processing system at a server node by at least one client processing system at least on client node, said method comprising the steps of: generating at least one synchronization mode for the file, said synchronization mode being dependent upon how many and which processes in the network have the file open, and whether the file is open for read only or write access; and caching the file at the at least one client node in at least one client cache as determined by said generated synchronization mode; and managing access to said at least one client cache as determined by said generated synchronization mode.
Claim 13
Dependent Claim
34 words
The method of claim 10 wherein a first synchronization mode is generated if all opens for the file are at one client node, and at least one of the opens is for write access.
Claim 14
Dependent Claim
22 words
The method of claim 10 wherein a second synchronization mode is generated if the file is only open for read only access.
Claim 15
Dependent Claim
44 words
The method of claim 10 wherein a third synchronization mode is generated if the file is open by processes executing at more than one node, and the file is open for write access by at least one process executing in at least one node.
Claim 16
Dependent Claim
23 words
The method of claim 10 wherein a third synchronization mode is generated if a device containing the file is open for write access.
Claim 17
Dependent Claim
23 words
The method of claim 11 or 12 further comprising the step of accessing the client cache for a read access to the file.
Claim 18
Dependent Claim
21 words
The method of claim 11 further comprising the step of accessing the client cache for a write access to the file.
Claim 19
Dependent Claim
24 words
The method of claim 13 or 14 further comprising the step of accessing the server processing system for a read access to the file.
Claim 20
Dependent Claim
24 words
The method of claim 13 or 14 further comprising the step of accessing the server processing system for a write access to the file.
Claim 21
Independent Claim
154 words
A system for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said system comprising: means for creating at least one client cache in the at least one client processing system for caching blocks of the file at the at least one client node; means for classifying said file dependent upon which of a plurality of nodes have the file open, and which of a plurality of processes at each of said nodes have the file open for writes, and which of the processes at each of said nodes have the file open for reads; means for accessing said file from said at least one client cache in response to a first classification of said classifying means; and means for accessing said file from said server processing system in response to a second classification of said classifying means.
Claim 22
Independent Claim
154 words
A system for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said system comprising: means for creating at least one client cache in the at least one client processing system for caching blocks of the file at the at least one client node; means for classifying said file dependent upon which of a plurality of nodes have the file open, and which of a plurality of processes at each of said nodes have the file open for writes, and which of the processes at each of said nodes have the file open for reads; means for accessing said file from said at least one client cache in response to a first classification of said classifying means; and means for accessing said file from said server processing system in response to a second classification of said classifying means.
Claim 23
Independent Claim
146 words
A method for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said method comprising: creating at least one client cache in the at least one client processing system for caching blocks of the file at the at least one client node; classifying said file dependent upon which of a plurality of nodes have the file open, and which of a plurality of processes at each of said nodes have the file open for writes, and which of the processes at each of said nodes have the file open for reads; accessing said file from said at least one client cache in response to a first classification of said classifying means; and accessing said file from said server processing system in response to a second classification of said classifying means.
Claim 24
Independent Claim
146 words
A method for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said method comprising: creating at least one client cache in the at least one client processing system for caching blocks of the file at the at least one client node; classifying said file dependent upon which of a plurality of nodes have the file open, and which of a plurality of processes at each of said nodes have the file open for writes, and which of the processes at each of said nodes have the file open for reads; accessing said file from said at least one client cache in response to a first classification of said classifying means; and accessing said file from said server processing system in response to a second classification of said classifying means.
Claim 25
Dependent Claim
169 words
A computer program product having a computer readable medium having a computer program recorded thereon for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said computer program product comprising: means for creating at least one client cache in the at least one client processing system for caching blocks of the file at the at least one client node; means for classifying said file dependent upon which of a plurality of nodes have the file open, and which of a plurality of processes at each of said nodes have the file open for writes, and which of the processes at each of said nodes have the file open for reads; means for accessing said file from said at least one client cache in response to a first classification of said classifying means; and means for accessing said file from said server processing system in response to a second classification of said classifying means.
Claim 26
Dependent Claim
169 words
A computer program product having a computer readable medium having a computer program recorded thereon for accessing a file residing in a server processing system at a server node by at least one client processing system at least one client node, said computer program product comprising: means for creating at least one client cache in the at least one client processing system for caching blocks of the file at the at least one client node; means for classifying said file dependent upon which of a plurality of nodes have the file open, and which of a plurality of processes at each of said nodes have the file open for writes, and which of the processes at each of said nodes have the file open for reads; means for accessing said file from said at least one client cache in response to a first classification of said classifying means; and means for accessing said file from said server processing system in response to a second classification of said classifying means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |