MSDN Documentation

Optimizing .NET Builds

This document provides strategies and best practices for optimizing the build process of your .NET applications to reduce build times, improve resource utilization, and enhance developer productivity.

Introduction to Build Optimization

Build times can significantly impact the development cycle. Long build times can lead to context switching, reduced focus, and slower iteration. Optimizing your build process is crucial for maintaining a healthy and efficient development workflow.

Key Optimization Strategies

1. Incremental Builds

Ensure your build system supports and effectively utilizes incremental builds. Incremental builds compile only the code that has changed since the last build, saving significant time.

How it works: The build system tracks dependencies between files and recompiles only those affected by changes. Proper project structure and avoiding unnecessary global changes contribute to effective incremental builds.

2. Parallel Builds

Leverage multi-core processors by enabling parallel builds. This allows multiple projects within a solution to be built simultaneously.

Configuration:

dotnet build -m

The -m flag (or --max-cpu-count) tells the build to use as many processors as available.

3. Build Caching

Implement build caching to store the results of previously executed build steps. This can dramatically reduce build times for identical or partially identical builds.

Tools:

• Microsoft.Build.CentralPackageManagement: Manages NuGet package versions efficiently.
• BuildXL, Bazel: Advanced build systems with powerful caching capabilities.
• GitHub Actions Caching, Azure Pipelines Caching: CI/CD level caching for build artifacts and dependencies.

4. Reducing Dependencies

Minimize project dependencies and avoid circular dependencies. A flatter project structure generally leads to faster builds.

• Refactor large projects into smaller, more focused ones.
• Analyze and remove unnecessary project references.

5. Using Faster Build Tools

While dotnet build is standard, consider specialized build tools if extreme optimization is needed:

• XBuild (older): Can sometimes offer performance advantages in specific scenarios.
• Third-party build accelerators: Tools designed to speed up MSBuild.

6. Optimizing NuGet Package Management

Efficient NuGet package management is vital.

• Central Package Management (CPM): Use CPM to define package versions in a single file, simplifying updates and ensuring consistency.
• dotnet restore: Ensure package restore is performed efficiently and not repeatedly.

7. Build Performance Profiling

Understand where your build time is spent. Use profiling tools to identify bottlenecks.

Tools:

• MSBuild Structured Log Viewer: Provides detailed insights into the MSBuild execution process.
• dotnet build -v:diag: Generates diagnostic logs for detailed analysis.

8. Optimizing SDK and Tools

Keep your .NET SDK and build tools up to date. Newer versions often include performance improvements.

Ensure your build agents or developer machines have sufficient resources (CPU, RAM, fast storage).

Advanced Techniques

• Distributed Builds: For very large solutions, consider distributed build systems like Incredibuild.
• Pre-compiled Assets: In some scenarios, pre-compiling parts of your application can save time at runtime or during deployment.