mysql:
https://blog.csdn.net/weixin_52799373/article/details/125385105/
redis:
https://blog.csdn.net/weixin_52799373/article/details/123551744?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522170176187316800184151617%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=170176187316800184151617&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~blog~first_rank_ecpm_v1~rank_v31_ecpm-2-123551744-null-null.nonecase&utm_term=redis&spm=1018.2226.3001.4450
