disconnected: not connected to DevTools

[maulikprajapati]

I am using the fitnesse-fixtures-test-jre11-chrome-with-pdf Docker image for E2E testing and am running multiple containers simultaneously to reduce build pipeline time. However, I am encountering the following issue intermittently with random test suites:

Unable to capture page source for exception: null
org.openqa.selenium.WebDriverException: disconnected: not connected to DevTools

[fhoeben]

I've encountered this in the past myself. I never was able to find a precise root cause.
I believe the issue is not in my fixture code, or FitNesse, but this is really an issue between Selenium and Chrome or maybe even internally in Chrome.

Unless we are able to find a good reproduction path I'm unsure how to prevent these errors in the future.

There might be a combination of complexity of (JavaScript on) the pages being tested, size of the test suite or resources available on the machine that is running the tests (maybe of the docker container or the host the containers are running on).

Are you able to see some pattern in when the errors occur? For instance how many suites are running in parallel, other jobs running on the same docker host, early or later in the test run, or maybe which tests/suites were run before the test that shows the error?

[nobilexdev]

@fhoeben I haven’t noticed any specific pattern so far. There are 12 suites running in parallel in the pipeline. However, I did closely monitor the pod resources and observed that the CPU was at its peak. At the time of failure, about 20–25% of RAM was still available.