Recently, we have a DS ticket that said a user got banner error periodically on the home page. That means we got some BE errors on API requests. I checked NewRelic and nothing exception was found. I checked error logs on our server and only a few 500 errors. I can’t find further information about these errors. So I believe it was caused by an unstable network or it might be caused. I was not working on that task.

Until yesterday we were going to solve a cache memory issue and I still not realized that was caused by cache memory. After I had submitted that PR of fixing cache memory, I decided to look that DS ticket again. I notice there’s some clue. I could find banner errors on fullstory and that means we did get some request errors. Then I checked request logs on Cloudflare and here are unsuccessful requests.

This Friday when we’re demo case, we noticed that it took a long time to display content on the Home page. It happened occasionally and soon we found it happened only when we had login into ULP but not the HOME page. Particularly, if you remove the cookie flag auth0.is.authenticated and refresh the page, you can reproduce it. You might have to wait for more than 10s.

As a front developer, we should keep in mind what browsers are used by our customers. We say only modern browsers and IE 11 are supported, at least users won’t get an error on IE 11. Our config is : ['last 2 versions', 'ie >= 11'] and here’s detailed browsers: last 2 versions. If you find your config is different from this one, please ensure your config is a superset of the above list.