private static void printHistogramMetric(MetricRegistry registry, String metricName) {
    Histogram histogram = registry.getHistograms().get(metricName);
    System.out.println("Metric of " + metricName + ": ");
    System.out.println("Count: " + histogram.getCount());
    System.out.println("Median: " + histogram.getSnapshot().getMedian());
    System.out.println("95th: " + histogram.getSnapshot().get95thPercentile());
    System.out.println("99th: " + histogram.getSnapshot().get99thPercentile());
  }
Print out histogram data for the given metric name.
@param registry The {@link MetricRegistry} object.
@param metricName The metric name to print out
ambry-tools/src/main/java/com/github/ambry/tools/perf/NamedBlobMysqlDatabasePerf.java