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Can I clear the CVM cache? I believe that many inexperienced people are at a loss about this, so this article summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

In the development of Internet projects, the application of caching is very common. Caching can help pages load faster and reduce the load on servers or data sources. Whether the CVM cache is cleaned or not, the pros and cons should be weighed according to the situation of its own server to see whether its effect is greater than its disadvantages.

Why do you need caching

Generally speaking, the most performance-consuming part of a project is the database of the back-end service. However, the frequency of reading and writing in the database is often unevenly distributed, most of which are read more and write less, and there will be some complex judgment conditions for select, such as like, group, join and so on. These grammars consume performance very much, so there will be a lot of slow queries, so the database is easy to encounter bottlenecks in the read operation.

Then by placing a cache service in front of the database, we can effectively absorb uneven requests and resist traffic peaks.

In addition, if the application and the data source are not on the same server, there will be a lot of network consumption in the middle, which will also have a great impact on the response speed of the application. If the current application has less real-time requirements for data, adding cache on the application side can quickly improve efficiency.

Problems encountered in using caching

Caching can improve the overall performance of cloud server leasing, but it may also cause other problems. For example, after using the cache, it is equivalent to storing two copies of the data, one in the database and the other in the cache. When there is new data to write or old data to update, if only one of the data sources is updated, the data on both sides will be inconsistent.

1. Expiration time of the cache

The expiration time of the CVM design cache needs to be very skillful and must be combined with the actual business situation. Because if the expiration time of the design is too short, it will lead to poor cache effect and frequent write of data from the database to the cache. If the cache design expires for too long, it will lead to a waste of memory.

two。 Hit rate of cache

This is also a very important point in designing what data needs to be stored in the cache. If the design is not good, it may cause the cache hit rate to be too low and lose the cache effect. Generally speaking, for hot spot data, it is best to ensure that the hit rate is more than 70%.

3. Cache penetration / avalanche

It means that if the cache service goes down or is completely lost, it is possible that all traffic will be directly sent to the back-end database in an instant, which may cause a chain reaction, and the instant peak of requests may cause the database to fail to be hosted.

After reading the above, have you mastered the method to clear the cache of the CVM? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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