Hi there

Recently I was wondering at my NoScript-Icon. It told me that suddenly there's a script on that side it doesn't know and blocked it. I looked around some and on the end of the sourcecode theres a link to d1ros97qkrwjf5.cloudfront.net/42/eum/rum.js

Now I'm just careful and was wondering what at all this javascript might do? I'm not really good in programming and such and therefore wouldn't much be able to identify any code

Where'd you encounter this, exactly?

It's probably OK, Silent Strider. CloudFront.net is a redirection to Amazon CloudFront, which is a content delivery service. I suspect it may have something to do with ads on e621, but I'm not sure if that's all they do.

It's a part of a new Ruby on Rails performance management application we recently deployed, there's nothing malicious about it. That specific script deals with page load times.

I just opened the script in notepad, and I must say -I'm not the big shit on programming- that I have no idea.

RedRaven said:
It's probably OK, Silent Strider. CloudFront.net is a redirection to Amazon CloudFront, which is a content delivery service. I suspect it may have something to do with ads on e621, but I'm not sure if that's all they do.

Which ads? The only I've seen here are from BadDragon and Furoticon. I doubt they have something to do with Amazon.

Also the script makes a lot of comparisons... Any extension that you may have that displays ads? Like iminent or something?

Edit: Forget what I said, tony just said it

The RUM JavaScript library (rum.js) creates a cookie to read the navigation start time when a user leaves a page. This is accomplished by hooking an event (beforeunload or pagehide), depending on the browser.

RUM computes the amount of time spent on the network as the amount of time spent on the backend, exclusive of time spent waiting in the queue and web app. (These are provided by the agent.)

So essentially rum.js measures how long it takes from clicking on a link until the new page is fully loaded and rendered in your browser and some additional timestamps for events in between.
I didn't understand the reaction though.
What happens if a user takes far longer than your ApdexT setting?
Please enlighten me admin-sensei.

Akkira said:
So essentially rum.js measures how long it takes from clicking on a link until the new page is fully loaded and rendered in your browser and some additional timestamps for events in between.
I didn't understand the reaction though.
What happens if a user takes far longer than your ApdexT setting?
Please enlighten me admin-sensei.

It's statistic collecting. So we know where the kinks in the code are (seems mostly like the original danbooru base is CRAP in terms of sql queries)