pathUtils | joinCache memory leak

[Galcarmi]

Hey guys,

We use webpack in our services to bundle code.
A webpack compiler is being created for each bundling process by importing webpack creator function from webpack.
Webpack is using enhanced-resolve to resolve module paths.. We also have custom resolvers that extends ResolvePluginInstance which is a enhanced-resolve resolver AFAIK.
Those resolvers are injected to webpack using the plugins property

After a while, we saw that as the service bundle code a memory leak is increasing in our service.
(for each bundle a new compiler of webpack is created)

As you can see in the heap-dump picture, it is related to joinCache property.

This property can be found here. this is a non-exported global variable that never cleans.

As I can see it, you can help us in 2 ways,

1. Clean this Map every X interval (it will be amazing if you can provide a configuration for it)
2. Provide a function that cleans that cache and we will call it after every bundle process.

LMK if you need any further data/explanations,
Thanks 🙏🏼🙏🏼

[alexander-akait]

Oh, it was for cache, how many run do you have?

[Galcarmi]

@alexander-akait The service runs (potentially) infinite bundling processes

[Galcarmi]

I can create a PR for adding a clearCache function, WDYT?

By the way, there is a third option to use LRU cache object with fixed size

[Galcarmi]

@alexander-akait 🙏🏼

[Galcarmi]

created a fork with the fix
#418
i'll try it on my servers and update..

[Galcarmi]

Well, seems like it works, can we do something similar for enhanced-resolve?