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.NET8 Systemd Service Stuck? Here’s Why

Learn why your .NET8 app running as a systemd service gets stuck on startup and how to fix it using UseSystemd() and Type=notify.

byDev Solutions

April 18, 2025

Frustrated developer looking at a frozen systemctl command with a red warning alert and code hints like UseSystemd() and Type=notify for fixing stuck .NET8 systemd services.

⚠️ .NET8 applications running under systemd can get stuck due to incorrect service configurations.
🔧 Setting Type=notify ensures systemd waits for a readiness signal before marking the service as active.
🛠️ Failing to include UseSystemd() in the application can cause systemd to mistrack startup sequences.
📜 Checking journalctl logs and running the service manually can help diagnose startup issues.
🏗️ Proper systemd service configuration, including dependencies and restart policies, improves stability.

.NET8 Systemd Service Stuck? Here’s Why

Running a .NET8 application as a systemd service on Linux is a common setup, but developers often encounter an issue where the service gets stuck on startup. This problem can arise due to improper service configuration, missing .NET8 integration settings, or incorrect startup sequence handling. This guide explores why your .NET8 service might be stuck in systemd, how to fix it, and best practices to ensure smooth service operation.

How Systemd Manages Service Startup

Systemd is the modern service manager for Linux, responsible for starting, stopping, and supervising services. When a .NET8 application runs as a systemd service, several key components determine whether it starts correctly:

Unit Files: Define the service execution parameters in /etc/systemd/system/your-service.service.
Service Type (Type): Defines how systemd determines when the service is ready.
ExecStart: Specifies the actual command used to start the application.
Restart Policy: Controls how the service behaves after failures.

For .NET8 applications, misconfigurations in any of these areas can result in the service appearing "stuck" or failing to start properly.

Common Reasons .NET8 Systemd Services Get Stuck

1. Incorrect Service Type (`Type=simple`)

By default, systemd assumes all services start immediately (Type=simple). However, many .NET8 applications require time to initialize, particularly web APIs or background workers. If systemd doesn't receive an explicit notification of readiness, it can mistakenly assume the service is unresponsive.

2. Missing `UseSystemd()`

.NET applications running as Linux services need a special configuration to properly integrate with systemctl. The missing .UseSystemd() directive can prevent systemd from tracking the service status correctly, leading to an "activating" state that never resolves.

3. Dependency Issues

If a .NET8 service relies on another process (such as a database or message broker), but those dependencies aren't fully available at startup, the service might get stuck trying to connect. This is especially common in cases where network targets aren't ready.

4. Permission Issues

Running a .NET8 application as a systemd service under an unprivileged user can introduce issues related to file permissions, environment variables, and executable access.

5. Startup Deadlocks

If an application has internal blocking calls (e.g., waiting on an external API or an unreachable resource), it may become unresponsive at launch, leaving systemd waiting indefinitely.

How to Fix Systemd Startup Issues for .NET8 Services

1. Enable Proper Systemd Integration with `UseSystemd()`

The UseSystemd() method ensures that your .NET8 application interacts correctly with systemd and provides the necessary lifetime notifications.

Modify your Program.cs:

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;

public class Program
{
    public static void Main(string[] args)
    {
        Host.CreateDefaultBuilder(args)
            .UseSystemd() // Ensures systemd compatibility
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            })
            .Build()
            .Run();
    }
}

This small change helps systemd correctly recognize the service's status.

2. Use `Type=notify` to Ensure Proper Service Readiness

Changing the service type to notify ensures that .NET8 explicitly signals systemd when it is ready, preventing premature timeouts.

Modify the service file (/etc/systemd/system/your-service.service):

[Service]
ExecStart=/usr/bin/dotnet /path/to/your-app.dll
Type=notify
Restart=always

After making this change, reload systemd to apply the modifications:

sudo systemctl daemon-reload
sudo systemctl restart your-service

3. Define Dependencies to Ensure Services Start in the Correct Order

If your .NET8 application depends on another service (e.g., a database), specify this in the After= directive to prevent premature startup.

Example:

[Unit]
Description=My .NET8 Application
After=network.target postgresql.service

4. Run Your Service Manually to Identify Issues

If your service is stuck, run it manually outside of systemd to check for errors:

/usr/bin/dotnet /path/to/your-app.dll

If it fails, check for missing dependencies, runtime errors, or environment issues.

5. Review Systemd Logs for Debugging

Use journalctl to inspect logs and find out why the service isn’t starting:

journalctl -u your-service --no-pager -n 50

Common errors include missing environment variables, file permission issues, or dependency failures.

Example: Correct Systemd Service File for .NET8

To properly configure your .NET8 systemd service, use the following example:

[Unit]
Description=My .NET8 Application
After=network.target postgresql.service

[Service]
ExecStart=/usr/bin/dotnet /path/to/your-app.dll
WorkingDirectory=/path/to/your-app
User=myuser
Group=mygroup
Restart=always
Type=notify
Environment=DOTNET_ENVIRONMENT=Production
Environment=ASPNETCORE_URLS=http://+:5000
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

Key improvements:

Ensures systemd waits for readiness with Type=notify
Defines environment variables for smooth execution
Uses a non-root user for better security
Includes a file descriptor limit to avoid resource exhaustion

Additional Best Practices for .NET8 Systemd Services

Following best practices can help prevent stuck services:

Enable Comprehensive Logging
- Use Serilog or .NET8 built-in logging with systemd logs.
Define a Sane Restart Policy
- Use Restart=on-failure instead of always if failures require debugging.
Ensure Correct Resource Allocation
- Limit CPU and memory usage with systemd options like:
```
CPUQuota=50%
MemoryLimit=500M
```
Avoid Running Your Service as root
- Always define User= and Group= in your service unit file.

Alternative Solutions (If Issues Persist)

If your .NET8 service is still getting stuck, consider alternative deployment methods:

Use Docker or Podman: Running your application in a container isolates dependencies.
Implement Supervisor or PM2: These process managers can handle service restarts more reliably.
Check Linux Distribution Compatibility: Some distributions have stricter systemd policies.

Conclusion

Stuck .NET8 systemd services can be frustrating, but in most cases, the problem stems from incorrect configurations. Using UseSystemd(), setting Type=notify, and debugging service dependencies should resolve most issues. Following best practices and structured troubleshooting will ensure your service runs smoothly on Linux.