# US 8,543,782 B2 · Content-based, compression-enhancing routing in distributed, differential electronic-data storage systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,782 B2 - Document ID: US8543782B2 - Status: Granted - Kind: B2 - Application number: 11/411,467 - Filed: 2006-04-25 - Published: 2007-10-25 - Granted: 2013-09-24 - Earliest claimed: 2006-04-25 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Samuel A. Fineberg; Kave Eshghi; Pankaj Mehra; Mark D. Lillibridge - Inventors: Samuel A. Fineberg; Kave Eshghi; Pankaj Mehra; Mark D. Lillibridge - Web page: https://patentgrep.com/patent/US8543782B2 ## CPC - G06F 3/0635: {by changing the path, e.g. traffic rerouting, path reconfiguration} - G06F 3/0608: {Saving storage space on storage systems} - G06F 3/0641: {De-duplication techniques} - G06F 3/067: {Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]} - H04L 67/1097: for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS] - H04L 67/63: Routing a service request depending on the request content or context - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract One embodiment of the present invention includes a method for routing a data object, comprising a sequence of data units, to a particular component data-storage system, or particular group of component data-storage systems, within a distributed, differential electronic-data storage system by selecting one or more subsequences of data units from the data object, computing a characteristic value from the selected subsequences, computing an index from the characteristic value; and directing the data object to the particular component data-storage system, or to the particular group component data-storage systems, identified by the computed index. ## Claims ### Claim 1 A method for routing a data object, comprising a sequence of data units, to a particular component data-storage system, or particular group of component of data-storage systems, within a distributed, differential electronic-data storage system, the method comprising: selecting one or more subsequences of data units from the data object; computing one or more characteristic values from the selected subsequences; computing one or more indexes from the one or more characteristic values; and directing the data object to the particular component data-storage system, or to the particular group of component data-storage systems, identified by the one or more computed indexes. ### Claim 2 (depends on 1) The method of claim 1 wherein selecting one or more subsequences of data units from the data object further includes: selecting a window size; selecting an offset; and selecting window-size subsequences of data-units from the data object, the window-size subsequences of data-units offset from one another by a number of data units equal to the selected offset. ### Claim 3 (depends on 2) The method of claim 2 wherein the selected offset is equal to the window size, resulting in selection of a consecutive sequence of contiguous, but non-overlapping data-unit subsequences from the data object. ### Claim 4 (depends on 2) The method of claim 2 wherein the selected offset is equal to 1, resulting in selection of a consecutive sequence of n grams from the data object, where n is equal to the window size. ### Claim 5 (depends on 2) The method of claim 2 further including: selecting a length; and selecting up to a number of subsequences of data units from the data object equal to the selected length. ### Claim 6 (depends on 1) The method of claim 1 wherein computing one or more characteristic values from the selected subsequences further includes: generating one or more values for each selected subsequence of data units; and computing one or more characteristic values from one or more of the one or more generated values. ### Claim 7 (depends on 6) The method of claim 6 wherein generating one or more values for each selected subsequence of data units further includes employing a hash function to generate a hash value from each of the selected subsequences. ### Claim 8 (depends on 6) The method of claim 6 wherein computing one or more characteristic values from one or more of the one or more generated values further includes one of: computing one or more characteristic values by a numerical function that takes one or more generated values as arguments; and selecting one or more of the generated values as the one or more characteristic values. ### Claim 9 (depends on 8) The method of claim 8 wherein selecting one of the one or more generated values as the one or more characteristic values includes one of: selecting one or more maximum-valued generated values of the generated values; selecting one or more minimum valued generated values of the generated values; selecting an average value of the generated values; and selecting a median value of the generated values. ### Claim 10 (depends on 1) The method of claim 1 wherein computing an index from the one or more characteristic values further includes combining, when there are multiple characteristic values, the two or more characteristic values to produce an integer, dividing the integer by the number of component data-storage systems, or groups of component data-storage systems, and selecting the remainder following integer division as the index. ### Claim 11 (depends on 1) Computer instructions encoded in a computer-readable medium that implement the method of claim 1. ### Claim 12 A routing component of a distributed, differential electronic-data storage system that routes a data object, comprising a sequence of data units, to a particular component data-storage system, or particular group component data-storage systems, of the distributed, differential electronic-data storage system by: selecting one or more subsequences of data units from the data object; computing one or more characteristic values from the selected subsequences; computing one or more indexes from the one or more characteristic values; and directing the data object to the particular component of the data-storage system, or to the particular group of component data-storage systems, identified by the one or more computed indexes. ### Claim 13 (depends on 12) The routing component of claim 12 wherein selecting one or more subsequences of data units from the data object further includes: selecting a window size; selecting an offset; and selecting window-size subsequences of data-units from the data object, the window-size subsequences of data-units offset from one another by a number of data units equal to the selected offset. ### Claim 14 (depends on 13) The routing component of claim 13 wherein the selected offset is equal to the window size, resulting in selection of a consecutive sequence of contiguous, but non-overlapping data-unit subsequences from the data object. ### Claim 15 (depends on 13) The routing component of claim 13 wherein the selected offset is equal to 1, resulting in selection of a consecutive sequence of n grams from the data object, where n is equal to the window size. ### Claim 16 (depends on 12) The routing component of claim 12 further including: selecting a length; and selecting up to a number of subsequences of data units from the data object equal to the selected length. ### Claim 17 (depends on 12) The routing component of claim 12 wherein computing one or more characteristic values from the one or more selected subsequences further includes: generating one or more values for each selected subsequence of data units; and computing one or more characteristic values from one or more of the one or more generated values. ### Claim 18 (depends on 17) The routing component of claim 17 wherein generating one or more values for each selected subsequence of data units further includes employing a hash function to generate a hash value from each of the selected subsequences. ### Claim 19 (depends on 17) The routing component of claim 17 wherein computing one or more characteristic values from one or more of the one or more generated values further includes one of: computing the one or more characteristic values by a numerical function that takes one or more generated values as arguments; and selecting one or more of the generated values as the characteristic value. ### Claim 20 (depends on 12) The routing component of claim 12 wherein computing an index from the one or more characteristic values further includes combining, when there are multiple characteristic values, the two or more characteristic values to produce an integer, dividing the integer by the number of component data-storage systems, or groups of component data-storage systems, and selecting the remainder following integer division as the index.