Running dotnet-counters on a .NET 8 deployed to Cloud Foundry

README.md

Assumptions

• .NET 8 app
• dotnet buildpack
• CF SSH access

Publish

We need to the dotnet CLI installed on the target application instance. To get dotnet installed and not have the buildpack remove it during staging we need to use a Framework Dependent Deployment. If you're running dotnet publish on an ARM processor you need to specify the runtime as linux-x64 otherwise you will get an error trying to start the app.

dotnet publish -r linux-x64 -c Debug

Update your application manifest path attribute to the publish directory. Your app manifest should look something like this:

---
applications:
  - name: cf-dotnet-webapp
    buildpacks:
      - dotnet_core_buildpack
    memory: 1G
    stack: cflinuxfs4
    path: bin/Debug/net8.0/linux-x64/publish

Now cf push the app as normal.

Dotnet Tooling Installation

Now that we have the application pushed and running we can now cf ssh into the running app instance. From here we need to setup a couple of things first.

Add dotnet to the PATH env var.

export DOTNET_ROOT=/home/vcap/deps/0/dotnet-sdk
export PATH="$PATH:$DOTNET_ROOT"

Set a TMPDIR to the same directory as the running web app as the tooling requires this to be set:

export TMPDIR=/home/vcap/tmp

Install one or more performance tools. Some of the tools available:

• dotnet-counters to view Performance Counters.
• dotnet-dump to capture and analyze Windows and Linux dumps.
• dotnet-trace to capture runtime events, GC collections and sample CPU stacks.
• dotnet-gcdump to collect GC dumps.

Install the dotnet-counters tool since this a good first place to start an investigation:

dotnet tool install dotnet-counters --global
export PATH="$PATH:/home/vcap/.dotnet/tools"

Debugging

With the tooling installed we can now execute it. Each of the tools will need the PID of your .NET web app, so in our example app named cf-dotnet-webapp we use pidof to find the process id.

dotnet-counters monitor --process-id $(pidof cf-dotnet-webapp)