On-demand caching in a WAN separated distributed file system or clustered file system cache

摘要

A mechanism is provided in a data processing system for on-demand caching in a wide area network (WAN) separated distributed file system or clustered file system. The mechanism monitors file access by a plurality of cache sites in the WAN separated distributed file system or clustered file system. The mechanism identifies access patterns by cache sites. The mechanism shares the access patterns with the plurality of cache sites. A given cache site within the plurality of cache sites combines the access patterns with local access information and identifies files to pre-fetch based on the combined information.

主权项

1. A computer program product comprising a non-transitory computer readable storage medium having a computer readable program stored therein, wherein the computer readable program, when executed on a computing device causes the computing device to:
monitor, by a home site in a separated distributed file system or clustered file system, file access by a plurality of cache sites in the separated distributed file system or clustered file system; record, by the home site, file accesses in an activity table, wherein the activity table is a two-dimensional table indexed by time over a predetermined interval P and a granularity G, wherein each element in the activity table is a linked list of read and write elements; transform the activity table into a sorted activity table wherein each element in the sorted activity table is a linked list of read and write elements sorted by time; convert the sorted activity table into a converted activity table by creating a link to a preceding write for each element in the stored activity table having only reads and creating a link to a next set of reads for each element in the sorted activity table having only writes; identify, by the home site and based on the converted activity table, access patterns by cache sites; and share the access patterns with the plurality of cache sites, wherein a given cache site within the plurality of cache sites combines the access patterns with local access information and identifies files to pre-fetch based on the combined information.