In today’s digital environment, building fast and reliable web applications is more important than ever. Users have high expectations when it comes to website performance. Slow load times and downtime can lead to customer dissatisfaction and reputational damage.
One way to achieve fast and reliable web applications is to use caching. There are many types of caches that can be implemented in your application, including in-memory caches, browser caches, database caches, and CDN caches.
What is a cache? How is an in-memory cache different? How can I use an in-memory cache to improve the performance of my Nest.js application?
What is caching
Caching is the process of storing frequently accessed data in a temporary location to improve application or system performance. Cached data can be quickly retrieved and served to the user without having to be retrieved again from the original source.
Applications use caching to deliver content faster and more efficiently. This improves the user experience and reduces the load on the underlying system. Some of the most common cache types include in-memory caches, CDN caches, browser caches, and database caches.
What is in-memory caching?
In-memory caching is a type of caching where applications temporarily store frequently accessed data in the server’s memory. Instead of making costly database calls each time your app processes a request to access data, you can retrieve that data from memory.
Caching data in memory means that applications access data faster, which improves performance.
How to implement in-memory caching in your Nest.js application
Nest.js has built-in support for caching using drivers such as Redis and Memcached. However, for simplicity, this article uses the built-in memory caching module provided by Nest.js.
This section assumes you already have a Nest.js application created with the Nest CLI commands. nest new [app name]. To implement an in-memory cache for an endpoint, either the module, service, and controller files already exist, or nest generation instructions.you can learn more about Nest generation In the Nest CLI docs.
The first step in implementing an in-memory cache is cache module from @nestjs/common Add it to the module for the endpoint as shown below.
import { Module, CacheModule } from '@nestjs/common';@Module({
imports: [CacheModule.register()],
})
export class ExampleModule {}
Then you have to import cash service Inject into a Nest.js service that communicates with a database such as MongoDB. You can see how to do this in the following code example.
import { Injectable, CacheService } from '@nestjs/common';@Injectable()
export class ExampleService {
constructor(private readonly cacheService: CacheService) {}
async getData(): Promise<any> {
const cacheKey = 'my_data';
let data = await this.cacheService.get(cacheKey);
if (!data) {
data = await this.fetchData();
await this.cacheService.set(cacheKey, data, { ttl: 60 });
}
return data;
}
private async fetchData(): Promise<any> {
}
}
In the code example above, Example Service Usage cash service as a dependency.of getData The method uses the key (cache key), if the data is not in the cache, fetch it from the database and cache it for later use.
of cash service there is setting A method that takes an object as an argument. In this case, you can see how the values change. { ttl: 60 } Set the time-to-live to 60 seconds. This means that the service will automatically remove cached data after 1 minute.
Key benefits of in-memory caching include:
- Improved scalability: In-memory caching helps improve application scalability by offloading the load on the underlying data sources.
- Faster response time: Caching frequently accessed data in memory reduces the time it takes to retrieve the data and improves response time.
- Improved user experience: Faster response times and better scalability improve the user experience by reducing latency and improving overall application performance.
- Cost reduction: In-memory caching helps reduce the cost of running your application by offloading data sources.
Optimizing Nest.js Applications with In-Memory Caching
In-memory caching is a very effective way to improve overall application performance. We’ve seen how Nest.js implements in-memory caching and how it improves scalability and user experience. It also reduces response time and lowers the cost of running your application.
Get hands-on with caching concepts when building your next Nest.js API or application.
