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1, Introduction to Redis overview 1. NoSQL overview NoSQL refers to not only Sql, which is a non relational database. NoSQL has four categories KV key valueDocument database (bson, MongoDB)Column storage database (HBase, distributed file system)Figure relational database (storing relationships, such as Neo4j) 2. Redis introduction R ...

introduction With the growth of business volume, the cache schemes used generally go through the following steps: 1) query DB directly without cache; 2) Data synchronization + Redis; 3) Multi level cache has three stages. In the first stage, direct DB query can only be used in small traffic scenarios. With the increase of QPS, cache needs to ...

Spring Boot cache Several important concepts & cache annotation CacheCache interface, which defines cache operations. Implementations include RedisCache, EhCacheCache, ConcurrentMapCache, etcCacheManagerThe Cache manager manages various Cache components@CacheableIt is mainly for method configuration, and the results can be cached accordin ...

Take you hand in hand to disassemble the LRU algorithm summary LRU algorithm is a cache elimination strategy. The principle is not difficult, but it is more skilled to write bug free algorithms in the interview. It needs to abstract and disassemble the data structure layer by layer. labuladong in this paper will write you beautiful code. ...

1, Review the contents of L2 cache The L2 cache is built on the L1 cache. When receiving the query request, MyBatis will query the L2 cache first. If the L2 cache is not alive In, query the level-1 cache again. If there is no level-1 cache, query the database again. L2 cache - > L1 cache - > database. Unlike the L1 Cache, the L2 Cach ...

1. jedis class 1. First, we need to import the jedis package Latest jedis After that, we put it into the directory at the same level as src, and then right-click the item to find: Next, let's test. At the beginning, I encountered such a problem The reason is that I didn't open the server, so you must remember to open the server. Now let ...

Redis detailed notes Notes: the Redis course of crazy talking about Java in station B: https://www.bilibili.com/video/BV1S54y1R7SB 1, NoSQL overview 1. Why use NoSQL Now is the era of big data (data that cannot be solved by ordinary databases: big data (mass storage and parallel computing)) SQL => NoSQL 1. Bottleneck in sta ...

1, Multilevel cache architecture 2, Cache design 1. Cache penetration Cache penetration refers to querying a data that does not exist at all, and neither the cache layer nor the storage layer will hit. Generally, for the sake of fault tolerance, if the data cannot be found from the storage layer, it will not be written to the cache layer. ...

Chapter V use of documents Use file %Library. The file class provides several class methods that allow various operations on files. Copy file To copy a file, use the CopyFile() method, which returns a Boolean value indicating success or failure. This method takes four parameters: from - specifies the name of the source file.T ...

redis string source code analysis For details, please refer to the redis source code SDS H this file /* Note: sdshdr5 is never used, we just access the flags byte directly. * However is here to document the layout of type 5 SDS strings. */ /* In all structures: * len Indicates the length used * alloc Indicates the usable length * ...