Skip to main content

NPM–Change cache

Just before the start of my weekend, I got a message from one of our administrators, the disk space on one of our build servers was filling up. Whoops!

Yesterday I explained that a part of the disk consumption could be explained by the global packages folder of NuGet. But if you take a second look at the screenshot I shared, you certainly notice that the AppData folder also needs some attention:


Let’s further drill into this folder and well’ notice another culprit; the npm-cache folder!

What is the npm-cache folder?

The npm-cache folder serves as a local cache where NPM stores downloaded packages and their dependencies. When you install a package using NPM, it first checks if the package is already in the cache. If so, it avoids re-downloading it, which speeds up subsequent installations.

This cache helps reduce network requests and ensures that packages are readily available for future use.

On Windows, the default path for the NPM cache is %AppData%/npm-cache or %LocalAppData%/npm-cache.

On macOS and Linux, the default cache location is ~/.npm, which translates to /home/YOUR_USER/.npm.

How to change the npm cache location?

You can change the cache folder by using the NPM command line:

npm config set cache D:\\npm-cache --global

After running this command, you can verify the cache using:

npm --global cache verify

Remark: You also see another NuGet folder in the screenshot. This is the http cache folder of NuGet where the Visual Studio Package Manager and the dotnet tool store copies of downloaded packages in this cache. Packages are not expanded, and the cache has an expiration time of 30 minutes.

Popular posts from this blog

Podman– Command execution failed with exit code 125

After updating WSL on one of the developer machines, Podman failed to work. When we took a look through Podman Desktop, we noticed that Podman had stopped running and returned the following error message: Error: Command execution failed with exit code 125 Here are the steps we tried to fix the issue: We started by running podman info to get some extra details on what could be wrong: >podman info OS: windows/amd64 provider: wsl version: 5.3.1 Cannot connect to Podman. Please verify your connection to the Linux system using `podman system connection list`, or try `podman machine init` and `podman machine start` to manage a new Linux VM Error: unable to connect to Podman socket: failed to connect: dial tcp 127.0.0.1:2655: connectex: No connection could be made because the target machine actively refused it. That makes sense as the podman VM was not running. Let’s check the VM: >podman machine list NAME         ...

Cache stampede: when our cache turned against us

While investigating some performance issues, we ran into an ASP.NET Core API that cached a fairly expensive aggregation query for 60 seconds. Under normal load, that was fine: one request rebuilds the cache, everyone else reads from it. Under peak load, dozens of requests would arrive in that same expiry window, all see a cache miss, and all fire the same expensive query in parallel. The database didn't like that. That was the moment when our caching layer stopped helping and started hurting. A burst of requests comes in at the same time, all miss the cache, and all go hammer the database or the downstream API at once. That's a cache stampede . The cache was supposed to protect our backend, and for a few hundred milliseconds it did the opposite. Why this happens IMemoryCache.GetOrCreate (and its async sibling) looks like it protects you, but it doesn't add any locking on its own. Look at the naive version: public async Task<Report> GetReportAsync(string key) ...

The role of ActivitySource in OpenTelemetry for .NET

While doing some pair programming to integrate OpenTelemetry tracing to a .NET application, we had a discussion on how to use the ActivitySource . It looks simple. You new one up, give it a name, start an activity, done. The discussion started when we added a second ActivitySource with the exact same name in a different class. This made us wonder: "Are we duplicating traces now? Is this a memory leak? Do we need a singleton?" So we decided to dig deeper. This post is what we learned… What ActivitySource actually is ActivitySource is part of System.Diagnostics , not part of the OpenTelemetry NuGet packages. Microsoft built tracing primitives directly into the BCL, and OpenTelemetry's .NET SDK simply listens to them. This is why you can add distributed tracing to a library without taking a dependency on OpenTelemetry at all. An ActivitySource is a factory for Activity objects, and an Activity is .NET's name for what OpenTelemetry calls a span.(don’t ask m...