Replacement method and system for cached data in storage system, and storage system

Abstract

The invention discloses a replacement method and system for cached data in a storage system, and the storage system. The method comprises the steps of dividing a cache space of the storage system intoN cache modules in advance, and when the hit cache module exists in the N cache modules, accumulating a hit count of the hit cache module; inserting the hit cache module into an M-level queue with preset queue lengths of all levels, wherein the cache module hit for the first time is inserted in the first-level queue, and the queue of each level performs enqueuing operation and dequeuing operationaccording to an LRU replacement algorithm; and when the re-hit cache module exists in the ith-level queue, judging whether the cache module meets a condition of starting the (i+1)th-level queue or not according to a preset hit grading rule, and if yes, moving the cache module to the (i+1)th-level queue, or otherwise, performing queue adjustment on the ith-level queue according to the LRU replacement algorithm. The jitter problem of IO access performance is avoided; and the system access efficiency is improved.

Description

technical field [0001] The present invention relates to the field of storage technologies, in particular to a replacement method, system and storage system for cached data in a storage system. Background technique [0002] In the storage system, the cached data in the cache space will continuously insert new data and replace the cached data accordingly. In the prior art, an LRU (Least recently used, least recently used) replacement algorithm is generally used to replace cached data in the cache space. Please refer to figure 1 , figure 1 It is a schematic diagram of an LRU replacement algorithm in the prior art. figure 1 A linked list is used to save the cached data, and the newly inserted data will be inserted into the head of the linked list. Whenever the cache hits (that is, the cached data is accessed), the hit cached data is moved to the head of the linked list. When the linked list is full , to eliminate the cached data at the end of the linked list. However, the L...

AI Technical Summary

Problems solved by technology

However, the LRU replacement algorithm only considers the time factor, resulting in hot data (cache data with high access heat, that is, more hit times) being frequently replaced, resulting in IO (Input / Output, input / output) access The performance jitter problem reduces the access efficiency of the system

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