$ ./histogram.py "${DIR}" # basic example
$ ./histogram.py --help # for more infohistogram.py uses the latency data of all answers from each server to plot
a graph that can be used to analyze the performance of the servers.
The type of graph this tool generates is the logarithmic percentile histogram. See the link for full explanation of this graph and the reasoning why it's suitable to use for benchmarking.
The tool generates multiple graphs - all for queries with any RCODE, and then
graphs for every individual RCODE (if present, only codes 0-23 by default).
On the horizontal axis, you can read how many percent of queries were answered slower than the corresping response time on the vertical axis.
In other words, the 1.0 slowest percentile means that 99 % of queries were answered faster than the response time of this percentile. Please note both axis are logarithmic.
Keep in mind you have to have a large sample of queries to get any meaningful data for the lower slowest percentiles. The curve also typically flattens out for the slowest queries due to a configured timeout.
- You can specify various image file extensions in the
--formatargument to generate different image formats.