Do i need to cache connection? How to cache it?

[skorphil]

Hi, there are numerous articles over the web suggesting to cache mongoose.connection like so:

let cached = global.mongoose

if (!cached) {
  cached = global.mongoose = { conn: null }
}

however i didn't find anything related on mongoose docs.

Is it considered good practice to cache connection (to avoid unnecessary connections)? And what is the conventions of doing this?

[skorphil]

as far as my research went, seems like mongoose already has https://mongoosejs.com/docs/connections.html#connection_pools so no need in additional logic to cache connections. Am i right?

[vkarpov15]

That pattern is specifically for serverless runtimes, like AWS Lambda and Vercel Serverless Functions. If you are running Mongoose on a server, there's no need to use that pattern.

[skorphil]

That pattern is specifically for serverless runtimes, like AWS Lambda and Vercel Serverless Functions. If you are running Mongoose on a server, there's no need to use that pattern.

Thank you
Can this pattern be replaced with maxPoolSize: 1 for serverless functions or is it completely different concepts?

[vkarpov15]

Different concepts. This pattern is specifically for retaining connections between serverless function calls, so you don't need to recreate a connection to MongoDB every single time your serverless function runs. maxPoolSize doesn't help with retaining connections.