What is Memcached database and its working principle introduction

The MEMCACHED database is an open source distributed memory object cache system.It is mainly used to accelerate the database and API calls in the dynamic web application.By storing the frequent access to the data in the memory, the reading performance of the system can be significantly improved, thereby reducing the load of the back -end database. The working principle of MEMCACHED is very simple. It stores the data in the form of the key value pair. The key is arbitrary string, and the value can be different data types such as string, object, and hash table.When the application needs to access a certain data, first check whether the copy of the data in Memcached already exists.If you exist, take it out of the memory and return to the application directly, thereby avoiding the expenses of access to the database.If the data is not in MEMCACHED, the application needs to be obtained from the database and stores it in Memcache for subsequent access. Here are examples of workflow of a MEMCACHED database: 1. The application sends a data request to the MEMCACHED client. 2. The Memcached client performs hash calculation locally based on the request's key value to obtain the node server address where the data is located. 3. Send a request to the corresponding node server. 4. Node server check whether there is data for requests.If you exist, return the data. 5. If the data does not exist, the node server obtains the corresponding data through the back -end database and stores it into memory. 6. The node server returns the obtained data to the client. 7. After the client receives the data, it shows it to the user and save the data in Memcached for follow -up access. In order to use the MEMCACHED database, we need to add the corresponding code to the application and perform the necessary configuration.Below is a sample code using Memcached: python import memcache # Create a MEMCACHED client client = memcache.Client(['127.0.0.1:11211']) # Setting data client.set('key1', 'value1') # retrieve data data = client.get('key1') Print (data) # Output: Value1 In this example, we use the Python's `Memcache` module to create a Memcached client and specify the address of the Memcached server.Then, we use the `set` method to store a key value to the Memcached, and then use the` Get` method to obtain the corresponding data through the key. In order to achieve configurations related to Memcached, you need to set the corresponding settings on the Memcached server.These configurations include memory size, number of concurrent connections, expiration time, and other advanced options.By correcting the MEMCACHED server correctly, the performance and reliability of the system can be improved to meet the needs of different applications. To sum up, the Memcached database is a distributed memory object cache system for accelerating data access.It enhances the load of the back -end database by storing frequent access to data in memory and providing fast data retrieval.Using MEMCACHED can improve the performance and scalability of the system and provide users with a better user experience.