protected void logDurationInfo(List<? extends DistStageAck> acks) { if (!log.isInfoEnabled()) return; String processingDuration = "Durations ["; boolean first = true; for (DistStageAck ack : acks) { if (first) first = false; else processingDuration += ", "; processingDuration += ack.getSlaveIndex() + " = " + Utils.prettyPrintMillis(ack.getDuration()); } log.info("Received responses from all " + acks.size() + " slaves. " + processingDuration + "]"); }