78 lines
3.7 KiB
Markdown
78 lines
3.7 KiB
Markdown
---
|
|
title: Pageview Time Experiment
|
|
date: 2019-08-19
|
|
---
|
|
|
|
My blog has a lot of content in a lot of diverse categories. In order to help me
|
|
decide which kind of content I should publish next, I have created a very
|
|
simple method to track pageview time and enabled it for all of my blogposts. I'll
|
|
go into detail of how it works and potential risks of it below.
|
|
|
|
The high level idea is that I want to be able to know what kind of content has
|
|
people's attention for the longest amount of time. I am using the time people
|
|
have the page open as a particularly terrible proxy for that value. I wanted to
|
|
make this data anonymous, simplistic and (reasonably) public.
|
|
|
|
## How It Works
|
|
|
|
Here is how it works:
|
|
|
|
|
|
|
|
When the page is loaded, a [javascript file records the start time](/static/js/pageview_timer.js).
|
|
This then sets a [pagehide handler](https://developer.mozilla.org/en-US/docs/Web/API/Window/pagehide_event)
|
|
to send a [navigator beacon](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/sendBeacon)
|
|
containing the following data:
|
|
|
|
- The path of the page being viewed
|
|
- The start time
|
|
- The end time recorded by the pagehide handler
|
|
|
|
This information is asynchronously pushed to [`/api/pageview-timer`](https://github.com/Xe/site/blob/91d7214b341088edba7a37a83a753e75ed02d7ad/cmd/site/pageview.go)
|
|
and added to an in-memory prometheus histogram. These histograms can be checked at
|
|
[`/metrics`](/metrics). This data is not permanently logged.
|
|
|
|
## Security Concerns
|
|
|
|
I believe this data is anonymous, simplistic and public for the following reasons:
|
|
|
|
I believe this data is anonymous because there is no way for me to correlate users
|
|
to histogram entries, nor is there a way for me to view all of the raw histogram
|
|
entries. This site records the bare minimum for what I need in order to make sure
|
|
everything is functioning normally, and all data is stored in ephemeral in-memory
|
|
containers as much as possible. This includes any logs that my service produces.
|
|
|
|
I believe this data is simplistic because it only has a start time, a stop time
|
|
and the path that is being looked at. This data doesn't take into account things
|
|
like people leaving a page open for hours on end idly, and that could skew the
|
|
numbers. The API endpoint is also fairly unprotected, meaning that falsified data
|
|
could be submitted to it easily. I think that this is okay though.
|
|
|
|
I believe this data is public because I have the percentile views of the histograms
|
|
present on [`/metrics`](/metrics). I have no reason to hide this data, and I do not
|
|
intend to use it for any moneymaking purposes (though I doubt it could be to begin
|
|
with).
|
|
|
|
I fully respect the [do not track](https://allaboutdnt.com) header and flag in browsers.
|
|
If [`pageview_timer.js`](/static/js/pageview_timer.js) detects the presence of
|
|
do not track in the browser, it stops running immediately and does not set the pagehide
|
|
handler. If that somehow fails, the server looks for the presence of the `DNT` header
|
|
set to `1` and instantly discards the data and replies with a 404.
|
|
|
|
Like always, if you have any questions or concerns please reach out to me. I
|
|
want to ensure that I am creating useful views into how people use my blog
|
|
without violating people's rights to privacy.
|
|
|
|
I intend to keep this up for at least a few weeks. If it doesn't have any practical
|
|
benefit in that timespan, I will disable this and post a follow-up explaining how
|
|
I believe it wasn't useful.
|
|
|
|
Thanks and be well.
|
|
|
|
---
|
|
|
|
EDIT 2019-10-15: browsers disable this call from the context I am using and I don't
|
|
really care enough to figure out how to fix it. This experiment is over. Thank you
|
|
to everyone that participated. All data will be scrubbed and a followup will be
|
|
posted soon.
|