Ceph » mgr » Dashboard

Just attaching a screenshot of the existing "Histogram" details tab for the "Cluster >> OSDs" page when a single OSD is selected in the top table:

There appears to be 2 performance-related detail tabs ("Performance counter" and "Histogram") currently.

With the introduction of the embedded grafana dashboards, there will be yet another tab, i.e. "Performance Details" (if we want to keep label generic) or "OSD Performance".

In looking at the "Histogram" tab, it seems like the data in "Histogram" ought to be reconciled with one of the existing tabs. In looking at Ceph Dashboard v1, it appears that the Histogram was directly on top of the Attributes (OSD map) as an accompaniment.

Some interesting things to note about the "Histogram" is that the red boxes to indicate read/write is not indicative of the OSD status. It's unclear to me what this histogram is showing as there's no tooltip, mouse-over or anything to explain the green pixels moving around (when there are reads and writes).

If the data is of value and makes sense, this histogram probably should be combined into one of the other tabs (Attributes Performance counter), or transformed into something that would be more consumable for the user -- perhaps in the new tab containing the grafana dashboard or with some better explanation as to how to use it. If the data shown in Histogram is not useful and cannot be explained, should we consider removing this tab?

Thoughts?

FWIW, some background information about Perf histograms can be found in the documentation . It also mentions a Python script src/tools/histogram_dump.py that can be used to quickly visualize existing histogram data. I was not able to get this to work, but maybe it would be a good starting point on how to modify the current implementation?

Changed color of the background

LenzGr commented on Apr 21

As per our conversation during the standup today, we concluded that the Histogram in it's current form does not really provide any useful information, regardless of the color scheme used. It was decided that we should rather remove the current implementation in its entirety and try to come up with a better solution that visualizes this type of information.