private String getBackLogRatioDurationsString() {
    long now = Time.monotonicNow();
    return Arrays.stream(taskBacklogRatioDurations).filter(m -> m.timeSet > 0)
        .map(m -> m.name + ": " + ((now - m.timeSet) / 1000) + "s")
        .collect(Collectors.joining(", "));
  }
TezSessionPoolManagerMetrics collects, aggregates and exposes data from Tez sessions to Hive's own MetricsFactory.
This is independent of the Tez DagClient which is active only while running DAGs.
ql/src/java/org/apache/hadoop/hive/ql/exec/tez/TezSessionPoolManagerMetrics.java