Instrumentation

This document explains how to gather instrumentation logs and other diagnostic information from a running Dart Analysis Server (DAS) process.

Collect an instrumentation log

To collect an instrumentation log, DAS needs to be launched with the --instrumentation-log-file option, specifying a path for the log file. Since the IDE launches DAS, the steps are different for each IDE.

IntelliJ IDEA and Android Studio

  1. In IntelliJ IDEA, click Help > Find Action, type “Registry” and open the “Registry...” item.
  2. Scroll down to the dart.server.additional.arguments property, and set it's value to --instrumentation-log-file=/some/file.txt. If there are other arguments listed, which you wish to keep, add this new argument to the existing value, separated by whitespace.
  3. In the Dart Analysis panel, click the Restart Dart Analysis Server button.

After doing those steps, DAS will write an instrumentation log to the specified file (/some/file.txt above).

VS Code

See the steps outlined at the Dart Code documentation.

Open the analyzer diagnostics pages

DAS serves a variety of “diagnostics pages” as a website on localhost. Since the IDE launches DAS, the method of opening this website is different for each IDE.

IntelliJ IDEA and Android Studio

  1. In the Dart Analysis panel, click the Analyzer Settings button on the left with the gear icon. Note, this is different from the “Show Options Menu” button at the top, which also has a gear icon.
  2. Click the View analyzer diagnostics link. The analyzer diagnostics website should open in an external browser.

VS Code

  1. Open the command palette (Ctrl+Shift+P) and type “Dart: Open Analyzer Diagnostics”. The analyzer diagnostics website should open in an external browser.

Using the analyzer diagnostics pages

Status

The first of the analyzer diagnostics pages is the Status page. This page shows general information about the DAS process, including version information.

Code Completion

TODO

Communications

TODO

Contexts

TODO

Environment Variables

This page shows all system environment variables as seen from DAS.

Exceptions

TODO

LSP Capabilities

This page is available when DAS is launched as an LSP server, and shows the current Client and Server LSP Capabilities.

Memory and CPU Usage

This page shows current memory and CPU usage of DAS.

Plugins

TODO

Subscriptions

TODO

Timing

TODO