Config Loading Dynamically Prevents BRUM NPM-package Instrumentation in AngularJS

Applicability

Product: Splunk Real User Monitoring (BRUM) Area/Module: NPM Package Integration, AngularJS Environment: Web application with AngularJS, dynamic config loading Scenario: Teams migrating from self-hosted BRUM scripts to the NPM package; instrumentation not visible in Splunk Observability.

Description

When instrumenting Splunk BRUM with the NPM package in AngularJS, the instrumentation may not work if configuration is loaded dynamically at runtime. This issue typically occurs when the initialization (SplunkOtelWeb.init()) is delayed until after configuration is fetched from the backend, causing missing or incomplete telemetry in Splunk Observability.

Investigation

1. Confirm application uses dynamic config loading for Splunk BRUM initialization.
2. Review instrumentation code to identify when and how SplunkOtelWeb.init() is called.
3. Check if console logs include messages such as splunk-init and splunk-config, indicating successful initialization.
4. Verify if HAR file and debug logs are available for further troubleshooting.

Recommended Troubleshooting:

• Adjust the initialization code to output console logs:

  export const configFactory = (configService: ConfigService) => {
    return () => configService.load().then(_ => {
      const config = configService.get();
      console.log('splunk-init');
      console.log('splunk-config', config.splunk);
      SplunkOtelWeb.init(config.splunk);
    });
  }
  

• Ensure the token is not redacted in the logs (tokens used here are not secret).
• If splunk-init does not appear in the logs, the problem is likely with the application code rather than Splunk BRUM.

 

Resolution

To ensure successful BRUM instrumentation:

• Initialize as Early as Possible: Call SplunkOtelWeb.init() at the earliest point in application startup, ideally in index.html or before any network requests are made.
• Avoid Instrumenting After Dynamic Config Load: If configuration is fetched from the backend, initialization occurs too late to instrument the config fetch itself and other early requests.
• Provide Debug Output: Use console logs and HAR files to verify initialization and network activity.
• Check for Successful Initialization: If splunk-init and splunk-config are present in logs and telemetry appears in Splunk Observability, instrumentation is successful.

Related Links

AngularJS Instrumentation Best Practices

Revision History

Revision	Publish Date	Comments
1.0	01-Oct-2026	Initial Release