A few words explain redis cache penetration, breakdown, avalanche, and redis sentinel

A few words Redis Cache penetration 、 breakdown 、 An avalanche 、Redis sentry

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Redis（ Master slave copy , Sentinel mechanism , Cache penetration 、 Cache breakdown 、 Cache avalanche , Solve the problem of buffer penetration by using Bloom filter ）

type	Database state	Cache state
Cache penetration	There is no such data in the database	There is no such data in the cache
Cache breakdown	The database has this data	Cache single point expiration
Cache avalanche	The database has this data	A large number of caches have expired

Solution

• Cache penetration ：BloomFilter Intercept 、 The query results are stored in the cache and the life cycle is set （ Expiration time ） Shorter
• Cache breakdown ： Due to the continuous operation of single point expired data , Therefore, you can set the hotspot data to never expire , Mutexes can also be added to restrict a large number of threads from accessing data at the same time
• Cache avalanche ： Because a large number of data are expired , Therefore, it can be set randomly key The expiration time of , Cluster distribution can also query multiple key Put them in different libraries , You can also refresh the cache regularly

Redis sentry

yes Redis A process of , Monitor multiple by running independently Redis The situation of , Yes Master monitor , Also on the slave monitor , Keep it high redis The usability of . Sentinel cluster means that sentinels can also monitor each other's situation , More availability .