What′s New in dotTrace

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