void testSetup() throws IOException {
      // test metrics
      latencyHistogram = YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      // If it is a replica test, set up histogram for replica.
      if (opts.replicas > 1) {
        replicaLatencyHistogram =
          YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      }
      valueSizeHistogram = YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      // scan metrics
      rpcCallsHistogram = YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      remoteRpcCallsHistogram = YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      millisBetweenNextHistogram =
        YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      regionsScannedHistogram = YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      bytesInResultsHistogram = YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));
      bytesInRemoteResultsHistogram =
        YammerHistogramUtils.newHistogram(new UniformReservoir(1024 * 500));

      onStartup();
    }
Populated by testTakedown. Only implemented by RandomReadTest at the moment.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/PerformanceEvaluation.java