graphing strangeness with stacking and series ordering

[mleinart]

Imported from https://bugs.launchpad.net/bugs/1119987

Reported by	zach-zwily
Date Created	Feb 09, 2013

I'm seeing some very strange behavior when creating stacked graphs. Depending on how I order the series, the graph will be rendered very, very different. This is the first graph, which appears to render correctly:

However, if I simply swap the ordering of the targets, I get this:

Notice that the stacking on the right portion is really messed up, and there is a weird spike on the left around midnight. This might only be happening when one of the series doesn't have any data at the beginning of the graph, but I haven't confirmed that conclusively.

[zwily]

👍

[minaguib]

My team has learnt to look for telltale overlaps in stacked graphs (or avoid them completely) to deal with this bug in graphite.

It would be kind of awesome to trust stacked graphs output by graphite as correct.

[obfuscurity]

Likely related to #196.