MANAGING REPLACEMENT OF DATA IN A CACHE ON A NODE BASED ON CACHES OF OTHER NODES

摘要

Caches on nodes in a cluster are globally managed so that a data item may be retained in any of the caches. A replacement policy that governs the replacement of data items stored in the caches selects buffers for replacement according to factors that include the state of the caches of other nodes. Some cached data items are designated as globally shared and assigned a primary cache. If a buffer holds a copy of a data item whose primary cache is another node, then the data item in the buffer is favored for replacement over a local data item or a global data item for which this is the primary cache. Cache retention values of buffers on different nodes may be compared. The buffer with the lowest cache retention value is selected for replacement. The replacement policy may also account for the way other caches in the cluster are configured.