Memory leak on Nuxt SSR

[tilenpirih]

What version of Bun is running?

1.1.29

What platform is your computer?

windows WSL - docker

What steps can reproduce the bug?

1. Create empty nuxt project. You can also clone my repository of a minimal reproduction.
2. Create dockerfile

FROM oven/bun:1.1.29 AS base

WORKDIR /usr/src/app
FROM base AS build
ENV NODE_ENV=production

COPY . /usr/src/app
WORKDIR /usr/src/app
RUN bun install
RUN bun run build

FROM base AS app

COPY --from=build /usr/src/app/.output /prod/app
WORKDIR /prod/app

EXPOSE 3000

CMD [ "bun", "run", "server/index.mjs" ]

3. Run project in the docker
   docker build -t memoryLeak .
   and
   docker run -p 3000:3000 memoryLeak

4. Visit the page multiple times. You can use a tool like OHA to make a lot of requests. And run a command
   oha -c 2 -n 10000 --disable-keepalive http://localhost:3000

5. in the other console type
   docker stats [container name]
   You can see memory usage
   
   after 10000 requests
   
   after 100000 requests
   

What is the expected behavior?

If you edit dockerfile to run app with a Node instead of bun

FROM node:20-alpine AS base
WORKDIR /usr/src/app
FROM base AS build
ENV NODE_ENV=production
COPY . /usr/src/app
RUN npm install
RUN npm run build

FROM base AS app
COPY --from=build /usr/src/app/.output /prod/app
WORKDIR /prod/app

EXPOSE 3000
CMD [ "node", "server/index.mjs" ]

Memory usage in node after 100000 requests

The difference is obvious.

What do you see instead?

No response

Additional information

In package.json in scripts you can put
"debug:bun": "bun run build && bun --inspect .output/server/index.mjs"

and when you run bun run debug:bun in console you will see a URL for inspection. It could help with debugging the process, creating snapshots, etc...

[Jarred-Sumner]

My guess is the socket object in our node:http imlementation needs to do some additional cleanup work that it is not currently doing.

In #14384:

 protectedObjectTypeCounts: {
    Promise: 20001,
    UnlinkedProgramCodeBlock: 32,
    UnlinkedModuleProgramCodeBlock: 26,
    Function: 9,
    DebugHTTPServer: 1,
    GlobalObject: 1,
    Timeout: 1,
  },

In main:

{
  objectTypeCounts: {
    Object: 575954,
    Function: 436286,
    Array: 361073,
    string: 232655,
    JSLexicalEnvironment: 173841,
    BufferList: 40003,
    GetterSetter: 28880,
    Promise: 24955,
    "Immutable Butterfly": 23656,
    Headers: 20002,
    Request: 20001,
    Response: 20001,
    ProxyObject: 18242,
    FunctionRareData: 13504,
    AsyncFunction: 13189,

Note how in both cases, the Promise and the Headers/Request/Response are all still there. Something is keeping it alive forever. It's probably not emitting the close event.

[tilenpirih]

Any estimations when this could be resolved? IMO memory leaks and stability should be very high priority.

[scottix]

Does it make any difference if you set nitro preset in your nuxt config

  nitro: {
    preset: 'bun'
  },

[tilenpirih]

This is ram usage after 100000 requests and it seems in a normal range. It's still 10x more compared to npm so there is probably still some room for improvements. But atleast it's solve me headaches with memory leaks for now.