public void setWriteLatency(long writeLatency) {
      if (this.writeLatency != null) {
        this.writeLatency.set(writeLatency);
      } else {
        this.writeLatency = new AtomicLong(writeLatency);
      }
    }
Canary region mode-specific data structure which stores information about each region to be
scanned
hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java