LUA script to dump JSON output from wrk/wrk2

json.lua

-- example reporting script which demonstrates a custom
-- done() function that prints results as JSON

done = function(summary, latency, requests)
   io.write("\nJSON Output:\n")
   io.write("{\n")
   io.write(string.format("\t\"requests\": %d,\n", summary.requests))
   io.write(string.format("\t\"duration_in_microseconds\": %0.2f,\n", summary.duration))
   io.write(string.format("\t\"bytes\": %d,\n", summary.bytes))
   io.write(string.format("\t\"requests_per_sec\": %0.2f,\n", (summary.requests/summary.duration)*1e6))
   io.write(string.format("\t\"bytes_transfer_per_sec\": %0.2f,\n", (summary.bytes/summary.duration)*1e6))
   io.write(string.format("\t\"connect_errors\": %d,\n", summary.errors.connect))
   io.write(string.format("\t\"read_errors\": %d,\n", summary.errors.read))
   io.write(string.format("\t\"write_errors\": %d,\n", summary.errors.write))
   io.write(string.format("\t\"http_errors\": %d,\n", summary.errors.status))
   io.write(string.format("\t\"timeouts\": %d,\n", summary.errors.timeout))
   io.write("\t\"latency_distribution\": [\n")
   for _, p in pairs({ 50, 75, 90, 99, 99.9, 99.99, 99.999, 100 }) do
      io.write("\t\t{\n")
      n = latency:percentile(p)
      io.write(string.format("\t\t\t\"percentile\": %g,\n\t\t\t\"latency_in_microseconds\": %d\n", p, n))
      if p == 100 then 
          io.write("\t\t}\n")
      else 
          io.write("\t\t},\n")
      end
   end
   io.write("\t]\n}\n")
end

Thanks for sharing! Quite useful.

wrk supports running LUA scripts with '-s' flag, you should just run it like this:

$ wrk -s json.lua -c 100 -t 30 http://localhost:8080/whatever