0611~ self study class

Interview knowledge ：

Redis: Preliminary understanding

Cache breakdown ： When one key stay redis When it doesn't exist in the cache , There is... In the database , When encountering concurrent scenarios ( It's usually hot key), this key Called multiple times , At this time, cache breakdown will occur ;

terms of settlement :1 Set the hotspot to never expire 2. The bloon filter ;

Cache penetration ： When one key stay redis There is no... In the cache , It doesn't exist in the database either , And users keep sending requests , When encountering concurrent scenarios , Cache penetration will occur ;

terms of settlement : Add verification to the interface ;

Cache avalanche : When redis Many in cache key Accessed multiple times , But most key It's all overdue , At this time, there will be an avalanche ;

terms of settlement :1. Never expired data settings ;

                2. Cache data is set randomly , Prevent a lot of kdy At the same time ;

Custom annotation + Review of interceptors , Remember more interview questions !!!