`interceptors.cache` causing memory leak after `max-age=` time

[olessavluk]

Reproducible By

Run using node --expose-gc mem.mjs

https://gist.github.com/olessavluk/8353ba4e76277b137ed2d11b29ed3b6b

Logs & Screenshots

In 1s watch `external` memory NOT leaking
{
  rss: 59.625,
  heapTotal: 17.21875,
  heapUsed: 7.329780578613281,
  external: 3.241048812866211,
  arrayBuffers: 0.1122894287109375
}
Runnig 1000 request sequentially
{
  rss: 429.9375,
  heapTotal: 296.921875,
  heapUsed: 245.27692413330078,
  external: 27.9563570022583,
  arrayBuffers: 18.011958122253418
}
In 5s (after HTTP cache exipire) memory will start leaking
{
  rss: 429.984375,
  heapTotal: 296.921875,
  heapUsed: 245.27588653564453,
  external: 4.026281356811523,
  arrayBuffers: 0.58502197265625
}
Runnig 1000 request sequentially
{
  rss: 387.390625,
  heapTotal: 46.671875,
  heapUsed: 11.3831787109375,
  external: 249.49678134918213,
  arrayBuffers: 233.27368545532227
}
Runnig 1000 request sequentially
{
  rss: 632.515625,
  heapTotal: 49.671875,
  heapUsed: 13.965179443359375,
  external: 472.66299057006836,
  arrayBuffers: 465.9623489379883
}
Runnig 1000 request sequentially
{
  rss: 895.234375,
  heapTotal: 53.671875,
  heapUsed: 15.958457946777344,
  external: 711.3902835845947,
  arrayBuffers: 698.6510124206543
}
^ see how much `external` & `arrayBuffers` increased after second & third run?

Environment

node -v: v20.18.0
uname -a: ... 24.4.0 Darwin Kernel Version 24.4.0: Fri Apr 11 18:33:47 PDT 2025; root:xnu-11417.101.15~117/RELEASE_ARM64_T6000 arm64

[mcollina]

this is fixed by #4198

[olessavluk]

Even after this update I am still seeing memory usage (external) increase over time, just at a slower pace.

Seems to be still coming from cache, will try to narrow it down

[metcoder95]

I'm having hard time to see a real memory leakage, I can see heap drop from time to time and a sustained increase of RSS (which is expected) with slight variance.

[olessavluk]

created separate issue #4208