Introduction to Redis
Learn the concept of the cache and how Redis helps implement caching to improve the application's performance.
What is Redis?
Redis is an in-memory data store that can behave as a database, caching system, or even a message broker. Due to its in-memory nature, the Redis server will always be running on the RAM and all the data will actually be stored on the RAM itself. This comes with the great advantage that accessing the data from Redis can be much faster, but there’s a limitation too. If the Redis server is restarted, all of our data is lost. To prevent this, Redis also supports storing the data at regular intervals to persistent storage so that data loss never happens.
Redis is a NoSQL data store and stores data in the form of key-value pairs. It can store different types of data, like lists, sets, strings, etc. It can even help to implement the expiration of the data, transactional-based operations, and much more. Let’s discuss some of the real-world use cases of using Redis as a caching system and a message broker.
Using Redis as a caching system
Redis can be used as a caching system to speed up the performance of web applications. An example is the DNS looking up the IP address for a given URL. When Redis is used as a cache, it stores frequently accessed data in memory, which reduces the number of database calls required to retrieve the data. This can significantly improve the performance of web applications by reducing the latency caused by database calls. Let's understand it in detail using our DNS example.
Explanation:
Slide 1: For the very first time, when our machine makes a request for a particular URL, the request goes to the cache. Obviously, we won’t find the mapping of the IP address (also known as a cache miss), and then we’ll call DNS to get the IP address. In this process, once we get the IP address, we’ll store the URL and its IP address in a key-value pair in the cache.
Slide 2: After surfing the internet, when we again make a request for the same URL, the cache returns the IP address (also known as cache hit) with a much shorter response time. This makes the operation much faster.
Redis also allows for the setting of expiration times for cached data, which means that old data can be automatically removed from the cache to make room for new data. Some of the scenarios where Redis is a great choice as a caching system include:
Applications that require low-latency responses.
Applications that frequently access the same data. ...