I have been currently exploring Kibana visualizations of some test data, specifically horizontal bar charts. I had been attempting to bucket the x-axis by aggregation of terms when I was surprised to notice that, when using count as the ordering metric, manipulating the depth of the descending ordering caused the actual values of the counts results to change!
Specifically, I was looking at the top 10 fields in descending order, and their ordering was different depending on whether I had the order size set at 10 or 50. Furthermore, the total counts when hovering over the individual field results didn't always agree with the results of the count of a naive query on the field from the dataset in the "Discover" tab.
Specifically, when I queried the specific index for the specific "top" field, the count that was returned matched the count returned when I windowed the visualization ordering size to 50, but not to the resulting count of the same field when the ordering size was windowed to 10; there, the count was a full 20 items less!
Has anyone else experienced unstable sorting, or is there any explanation as to why changing the size of the ordering has an impact on the results returned?