Datadog Real User Monitoring breaks node express client server on IE11

Using the @datadog/browser-rum package with Node apollo web client fails on IE11.

Seeing multiple requests to https://run-http-intake.logs.datadoghq.com on IE11 that are different than Chrome. Unable to login to the application on IE11. Working theory is that datadogRUM is blocking other application requests on IE11. When datadogRUM is removed, the application is working correctly.

Chrome and IE11 requests:

• Request Method: POST RequestURL: https://rum-http-intake.logs.datadoghq.com/v1/input/pub{id}?_dd.application_id={id}&ddsource=browser&&ddtags=sdk_version:1.25.2.env:local&batch_time={timestamp}

Only IE11 request:

Request Method: CONNECT RequestURL: https://rum-http-intake.logs.datadoghq.com Proxy-Connection: Keep-Alive

Using the init method from the documentation like:

import { datadogRum } from '@datadog/browser-rum' 

datadogRum.init({
          applicationId: '<DATADOG_APPLICATION_ID>',
          clientToken: '<DATADOG_CLIENT_TOKEN>',
           site: '<DATADOG_SITE>',
           env: process.env.ENVIRONMENT,
            silentMultipleInit: true,
            sampleRate: 100,
            trackInteractions: false,
            useSecureSessionCookie: true,
})

Please let me know what additional information I should find to help with this issue. IE11 issues are no fun. Thank you!

[bcaudan]

Hi @carlpeaslee,

Thanks for all these details! I have been able to reproduce the issue on IE 11 on your demo application.

The issue is due to a mismatch between browser-rum and browser-logs version. I would advise you to either:

• install browser-rum@1.12.9 to match browser-logs version in your setup
• upgrade your browser-logs version to match your browser-rum version

I have tested with browser-rum@1.12.9 and the issue does not happen anymore.

[lauraeci]

@bcaudan this fixed our issue. Thanks for your help.