private void updateChunkFillerWaitTimeMetrics() {
    routerMetrics.waitTimeForFreeChunkAvailabilityMs.update(waitTimeForCurrentChunkAvailabilityMs);
    routerMetrics.waitTimeForChannelDataAvailabilityMs.update(waitTimeForChannelDataAvailabilityMs);
    waitTimeForCurrentChunkAvailabilityMs = 0;
    waitTimeForChannelDataAvailabilityMs = 0;
  }
Update metrics related to how long a channel had to wait for a chunk to become available for filling, and
how long the chunk had to wait for data to become available in the channel.
ambry-router/src/main/java/com/github/ambry/router/PutOperation.java