What′s New in dotTrace

In this release, we’re introducing tabs to dotTrace. You can now open the same snapshot in multiple tabs with different filter configurations. This lets you examine various aspects of your performance data simultaneously. You can analyze one dataset in one tab while applying different filters in another and switch between views without resetting your filters.

We’ve introduced comprehensive support for the Undo and Redo actions and filter history in the standalone version of dotTrace. Now, each filter change is recorded, making it easy to revert to any previous state. Use the Undo button or hotkey to undo the latest change and the Redo button to reapply it. You can also access a drop-down list to revert multiple steps at once, with changes listed in chronological order.

• dotTrace Viewer now uses a new rendering engine across all platforms. If you encounter issues with the updated viewer, you can disable the Use new cross-platform dotTrace Viewer by default option in dotTrace Home | Settings.
• The standalone version of dotTrace for macOS and Linux gets the Options window.
• We fixed the issue with missing kernel events on Windows: Kernel sampling events were missing in Timeline snapshots due to interference from Windows Defender.
• We've also made other smaller improvements and bug fixes to enhance usability.

Now, you can profile applications based on the MAUI framework.

Currently, dotTrace supports:

• macOS – Mac Catalyst applications targeting .NET 7.0+. Timeline profiling only.
• Windows – WinUI applications targeting .NET 7.0+. All profiling types are supported. Attaching to already running applications is available only for the Timeline and Sampling types.

The support is available for dotTrace standalone and dotTrace integrated into Rider and ReSharper.

dotTrace now includes user interface (UI) presets. The presets adjust the UI to show only the profiling settings relevant to specific applications: General (all application types), Unity developer, and Unreal Engine developer.

We improved profiling on macOS:

• Now, the standalone version of dotTrace lets you specify application bundles (.app) instead of executable files.
• dotTrace in Rider can profile macOS run configurations. The following target frameworks are supported: net7.0-macos, net8.0-macos, net7.0-maccatalyst, net8.0-maccatalyst, Xamarin.Mac.

Now, when configuring a Timeline profiling session, you can specify the following advanced options:

• Sampling rate – Lets you find the optimal balance between the performance of the profiled application and data accuracy.
• Sample allocations every … KB for native allocations – Lets you improve the performance of snapshot analysis by reducing the amount of collected data, i.e. snapshot size.
• Download in background option for native symbol files – Downloads symbol files during the profiling session.

Instead of analyzing the Call Tree, you can now view performance profiling data right in the source code. The Source view displays time distribution information for specific lines of code. As of now, this feature is only available for timeline snapshots taken on Windows.

Now, the Call Tree view lets you group call stacks by individual threads, allowing deeper insight into thread-specific performance issues.

The standalone version of dotTrace is now available on Linux and macOS. Now, you can perform the full profiling workflow on these operating systems, including collecting and analyzing performance snapshots.

Before this release, sampling, tracing, and line-by-line performance snapshots had to be opened in the legacy Performance Viewer, while timeline snapshots were opened in the more modern Timeline Viewer. This worsened the overall user experience, since the viewers have different user interfaces and approaches to snapshot analysis.

Now we’re getting rid of the Performance Viewer in favor of the dotTrace Viewer (formerly the Timeline Viewer). dotTrace will use it to open snapshots of all types. However, you may continue to use the discontinued Performance Viewer if you’d like. If you opt to stick with the Performance Viewer, we would love to hear your reasons for doing so. Your feedback is greatly appreciated!

As the dotTrace Viewer now opens snapshots of all types, you can use all of its powerful features when comparing performance snapshots:

• The new “comparison as a filter” concept makes it easier to compare sampling, tracing, and line-by-line snapshots.
• Now you can filter subsystems in sampling, tracing, and line-by-line snapshots.
• The dotTrace Viewer now has a Plain List view. It’s available for sampling, tracing, and line-by-line snapshots, and also for timeline snapshots.

dotTrace now provides more details for native system calls in the Timeline Call Tree, including Windows kernel calls (ntoskrnl.exe), device driver calls (*.sys), and more.

You can now open NetTrace files collected with dotnet-trace collect: from the dotTrace Home menu, click Open Snapshot and choose a .nettrace file.

Now dotTrace supports SQL Server events from the Microsoft.Data.SqlClient provider on Windows (.NET Core, .NET 5+), as well as macOS and Linux (.NET Core 3.0+, .NET 5+).

You can now navigate the dotTrace Home window using only keyboard combinations. No mouse is needed. Each UI element is assigned to a key or key sequence. There are two ways to view the assigned keys and interact with UI elements:

• Hold Alt and press a key or key sequence (default).
• Press the mode-toggle key, then press a key or key sequence.

You can choose which to use in dotTrace Home | Settings.

You can now attach the profiler to an already running application by simply dragging the special icon onto the application window.

• You can now edit the names of snapshots.
• You can now open snapshots by dragging the corresponding files onto the dotTrace Home window.
• The snapshots list now preserves the sorting state between dotTrace launches.
• The snapshots list now uses the system date format.

• You can now disable snapshot auto-saving. If you do, when you close the Timeline or Performance Viewer, dotTrace will ask you whether you want to save the collected snapshots.
• It’s now possible to pin threads in the Threads filter in the Timeline Viewer.
• The Configuration2Xml tool now uses the same UI as the dotTrace Home window.

When you close a Timeline snapshot, dotTrace saves the state of the user interface, including selected time intervals, applied filters, and so on. Next time you open the snapshot, dotTrace will restore the UI to the same state.

The dotTrace command-line tool and dotTrace in Rider now let you collect data on asynchronous calls on macOS and Linux. To get this data, use the Timeline profiling mode. The Call Tree shows async calls, including awaits and continuations.

The dotTrace command-line tool and dotTrace in Rider can now profile child processes of applications on macOS and Linux in the Timeline profiling mode. This support is available only for .NET 5+ applications.

It’s now possible to profile native applications on Windows. When starting a profiling session, you have the option to download native source symbol files from remote servers. Native profiling is only available for the Timeline profiling type.

We’ve completely reworked the dotTrace Home screen. It’s much easier to configure and start new profiling sessions, work with snapshots, and perform other basic operations.

You can install and use the dotTrace command-line profiler as a dotnet global tool: dotnet tool install --global JetBrains.dotTrace.GlobalTools --version 2021.1.0