Question: how to make swc-node to use less memory

[erfanium]

I use @swc-node to run TypeScript backend in production. because i don't like to add a build step to my workflow, on-the-fly transpilation just makes life easier

everything works fine, but the extra memory usage caused by swc is a downside to me.

to reproduce:

import { memoryUsage } from "node:process";

setInterval(() => {
  console.log(memoryUsage());
}, 2000);

node main.js: rss: 45MB, heapTotal: 6MB, heapUsed: 6MB, external: 421KB, arrayBuffers: 18KB
deno main.ts: rss: 52MB, heapTotal: 11MB, heapUsed: 10MB, external: 76KB, arrayBuffers: 0
node -r @swc-node/register main.ts: rss: 102MB, heapTotal: 30MB, heapUsed: 23MB, external: 592KB, arrayBuffers: 57KB

There is a huge gap here. I was able to 60% reduce one of my project rss, just by compiling the source code before runtime.

I wonder is there anyway to consume less memory for production usage? maybe unload/free the swc compiler after a while during runtime.

I can work on a PR, but i have no idea to start

[Brooooooklyn]

Don't use register in production, it's for development usage

[erfanium]

@Brooooooklyn
well there is a similar threads in ts-node: TypeStrong/ts-node#104 i can reference. that's an old debate

Many are using ts-node in production, so maybe it's better to create this module not only for development usage

[yeliex]

You can use it in production for free, but it is not recommended. and I guess it would never be officially supported

[matzeeable]

Hey @Brooooooklyn and @kdy1,

We are successfully using the project within our development environment, but we are now reaching our limits.

Since we have introduced two more microservices (Node.js backends written in TypeScript) into our monorepo, we have now reached a total of 16 services. We are currently experiencing out-of-memory (OOM) errors on several developer machines, and after some research, I have noticed that the SWC Node Register allocates a significant amount of memory. We are using the following command to run the backend in watch mode ~690 MB:

node --watch --watch-preserve-output --import @swc-node/register/esm-register --enable-source-maps ./src/index.ts

After some time, the memory reduces, but I do not know exactly if this comes from the SWC GC ~410 MB:

Running without --import and directly using .js build files: ~260 MB:

Switching to an alternative @oxc-node/register ~500 MB:

And the same, after some time, the memory reduces ~300 MB:

---

Comparison:

• @swc-node/register after startup: ~690 MB:
• @swc-node/register after some time: ~410 MB:
• @oxc-node/register after startup: ~500 MB
• @oxc-node/register after some time: ~300 MB
• Without any --import: ~260 MB

But @exc-node/core is not usable for us due to emitDecoratorMetadata limitations, as we are heavily using TypeORM.

Could #1014 solve these issues? What do you think?