View traces across projects

By default, the Trace Explorer page only searches your selected project for trace data. When a trace has data stored in multiple projects, as might occur when an application in one project makes a call into an application hosted by another project, you need to perform the following steps to view all spans in the trace:

1. Create a trace scope that lists the Google Cloud projects that store the spans in a trace. For information about trace scopes, see Create and manage trace scopes.

2. Open the Trace Explorer page and set the scope to be the trace scope that you created in the previous step. For more information, see Configure which projects are searched for span data.

   Your Identity and Access Management (IAM) roles on the projects listed in the trace scope and the time-range setting determine what data is displayed. The trace scope only specifies which resources are searched.

   When the Trace Explorer page opens, it searches the resources listed in the default trace scope, provided that scope is accessible. When that scope isn't accessible, your Google Cloud project is searched. You can set which trace scope is the default trace scope.

Note: The Trace Explorer and legacy Trace Explorer pages use different rules to search for trace data. The Trace Explorer page only searchs the projects you specify in a trace scope. In contrast, the legacy Trace Explorer page searches all projects in an organization. Because the legacy Trace Explorer page searches your organization, you can use it to help you identify the projects to add to your trace scope. For information about how to identify these projects, see Migrate to trace scopes.