I have a new favourite way to plot metrics that feature some sort of daily progression. It looks like this:
To explain why I like it so much, we must, regrettably, look at the sort of thing it’s replacing:
I know, I know. My way displays less information!
But, and I may be the only one with this problem, I confess to finding it a little hard to process. I have no intuitive sense of the shape of the traditional plot, since it’s always changing. It also frustrates me that this time yesterday is perpetually just out of sight.
I’m fixing the problem of changing shape by locking the time range. It is always a calendar day and today’s (incomplete) data is drawn as a line. The ghost of yesterday’s1 data allows for an intuitive comparison.
Since the current time is no longer anchored to the edge of the plot, a vertical line makes it easier to see. It sweeps across over the course of a day, and at midnight the green line disappears to become the ghost for the next day.
I find this plot much easier to understand intuitively—the fixed shape speaks to me in a way the sliding half-shape did not—as well as rather satisfying to look at. Unfortunately, I don’t know what it is called, which makes it tricky to evangelise it to my colleagues. Please do email me and let me know if this technique has a name.
PS. I have some notes about implementing this in Grafana.