关键词: Redis, 压缩列表, 连锁更新, 优化

Abstract: Aiming at solving the chain update problem exists in Redis ziplist update mechanism in the worst case, after thoroughly analyzing realization principle of Redis ziplist update mechanism, two kinds of optimization schemes are proposed, scheme one, by optimizing the chain update algorithm, modify it to sequential traversal update mechanism based on statistics, which is an effective solution for the problem of high time complexity when chain update occurs in Redis ziplist. The new mechanism reduces the update time complexity from [O(N2)] to [O(N)]. When there is a chain update of a large number of nodes, consumption of time spent is close to the time which the node is inserted without chain update. Scheme two, by optimizing the compression list node structure, eliminates the chain update phenomenon, thereby reducing the additional time due to the chain update. Comparing with optimizing the update function, it has better performance. Experiments show that the new scheme brings remarkable optimization effect without affecting the original function.

Key words: Redis, ziplist, chain update, optimization