Resource sharing facility functions as a controller for secondary storage device and is accessible to all computers via inter system links
First Claim
1. A method of sharing data items and locks and of supporting remote procedure calls and coordinated process groups between a plurality of computers each having one or more respective central processing units, respective main storage associated with the central processing units of each computer and respective high-level caches maintained in the main storage of the respective computer, said method comprising the steps of:
- (a) providing a resource sharing facility with a medium level cache and a resource sharing facility database and capable of selectively storing a set of data items in said medium level cache and in said resource sharing facility database;
(b) connecting said resource sharing facility to all of said computers by intersystem links so that said resource sharing facility is accessible to all of said computers;
(c) operating said resource sharing facility as a controller for at least one secondary storage;
(d) maintaining in said resource sharing facility control information and logic needed for mapping medium level cache data to said secondary storage and said! secondary storage data to said medium level cache for each data item in said medium level cache where said resource sharing facility optionally unifies redundant control information for said computers; and
(e) synchronizing, when required, cache data maintained in the resource sharing facility and persistent data residing in said secondary storage by delegating input/output operations from said computer to said resource sharing facility.
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Accused Products
Abstract
A method and architecture for sharing data items using a resource sharing facility with a medium level cache accessible to all of the computers which are to share and connected to the computers by fast intersystem links. The resource sharing facility also acts as an ordinary secondary storage controller and in the resource sharing facility the control information and logic is provided which is needed for the mapping of cache data to the secondary storage and vice versa.
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Citations
31 Claims
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1. A method of sharing data items and locks and of supporting remote procedure calls and coordinated process groups between a plurality of computers each having one or more respective central processing units, respective main storage associated with the central processing units of each computer and respective high-level caches maintained in the main storage of the respective computer, said method comprising the steps of:
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(a) providing a resource sharing facility with a medium level cache and a resource sharing facility database and capable of selectively storing a set of data items in said medium level cache and in said resource sharing facility database; (b) connecting said resource sharing facility to all of said computers by intersystem links so that said resource sharing facility is accessible to all of said computers; (c) operating said resource sharing facility as a controller for at least one secondary storage; (d) maintaining in said resource sharing facility control information and logic needed for mapping medium level cache data to said secondary storage and said! secondary storage data to said medium level cache for each data item in said medium level cache where said resource sharing facility optionally unifies redundant control information for said computers; and (e) synchronizing, when required, cache data maintained in the resource sharing facility and persistent data residing in said secondary storage by delegating input/output operations from said computer to said resource sharing facility. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of sharing data items and locks and of supporting remote procedure calls and coordinated process groups between a plurality of computers each having one or more respective central processing units, respective main storage associated with the central processing units of each computer and respective high-level caches maintained in the main storage of the respective computer, said method comprising the steps of:
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(a) providing a resource sharing facility with a medium level cache and a resource sharing facility database and capable of selectively storing a set of data items in said medium level cache and in said resource sharing facility database; (b) connecting said resource sharing facility to all of said computers by intersystem links so that said resource sharing facility is accessible to all of said computers; (c) operating said resource sharing facility as a controller for at least one secondary storage; (d) maintaining in said resource sharing facility control information and logic needed for mapping medium level cache data to said secondary storage and secondary storage data to said medium level cache for each data item in said medium level cache where said resource sharing facility optionally unifies redundant control information for said computers; and (e) synchronizing when required, cache data maintained in the resource sharing facility and persistent data residing in said secondary storage by delegating input/output operations from said computer to said resource sharing facility; (f) activating in said resource sharing facility a set of processes in response to at least one request from a respective program running in a respective computer; and (g) supporting in each process of said set requests from any of said computers to write a data item in said medium-level cache, to register interest in a data item, to write a data item to secondary storage, to read a data item from said medium-level cache to a given location in the main storage of the requesting computer, to lock a data item against update or read by other programs, to unlock a lock, to perform regular I/O operations, and to perform any combination of the above requests as a single operation. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A computer system capable of sharing data items and locks and of supporting remote procedure calls and coordinated process groups, comprising:
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a plurality of computers each having one or more central processing units, respective main storage associated with the central processing unit or units of each computer and respective high-level caches maintained in the main storage of the respective computer; a resource sharing facility with a medium level cache and a resource sharing facility database and capable of selectively storing a set of data items in said medium level cache and in said resource sharing facility database; and high-speed intersystem links connecting said resource sharing facility to all of said computers so that said resource sharing facility is accessible to all of said computers, said resource sharing facility being provided as a controller for at least one secondary storage, said resource sharing facility being provided with control information and logic needed for mapping medium level cache data to said secondary storage and secondary storage data to said medium level cache for each data item in said medium level cache, cache data maintained in the resource sharing facility and persistent data residing in said secondary storage being synchronized by delegation of input/output operations from the computer to the resource sharing facility. - View Dependent Claims (30, 31)
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Specification