diff --git a/iotdb-core/metrics/core/src/main/java/org/apache/iotdb/metrics/core/type/IoTDBTimer.java b/iotdb-core/metrics/core/src/main/java/org/apache/iotdb/metrics/core/type/IoTDBTimer.java
index adba7f80e715..19def110f4b4 100644
--- a/iotdb-core/metrics/core/src/main/java/org/apache/iotdb/metrics/core/type/IoTDBTimer.java
+++ b/iotdb-core/metrics/core/src/main/java/org/apache/iotdb/metrics/core/type/IoTDBTimer.java
@@ -26,7 +26,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.Objects;
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
 public class IoTDBTimer extends AbstractMetricMBean implements Timer, IoTDBTimerMBean {
@@ -56,62 +56,36 @@ public HistogramSnapshot takeSnapshot() {
 
   @Override
   public double getSum() {
-    HistogramSnapshot snapshot = this.takeSnapshot();
-    if (Objects.isNull(snapshot)) {
-      LOGGER.warn("Snapshot is null, can't get sum, return 0.0 instead.");
-      return 0.0;
-    }
-    return snapshot.getSum();
+    return Optional.ofNullable(takeSnapshot()).map(HistogramSnapshot::getSum).orElse(0.0);
   }
 
   @Override
   public double getMax() {
-    HistogramSnapshot snapshot = this.takeSnapshot();
-    if (Objects.isNull(snapshot)) {
-      LOGGER.warn("Snapshot is null, can't get max, return 0.0 instead.");
-      return 0.0;
-    }
-    return snapshot.getMax();
+    return Optional.ofNullable(takeSnapshot()).map(HistogramSnapshot::getMax).orElse(0.0);
   }
 
   @Override
   public double getMean() {
-    HistogramSnapshot snapshot = this.takeSnapshot();
-    if (Objects.isNull(snapshot)) {
-      LOGGER.warn("Snapshot is null, can't get mean, return 0.0 instead.");
-      return 0.0;
-    }
-    return snapshot.getMean();
+    return Optional.ofNullable(takeSnapshot()).map(HistogramSnapshot::getMean).orElse(0.0);
   }
 
   @Override
   public int getSize() {
-    HistogramSnapshot snapshot = this.takeSnapshot();
-    if (Objects.isNull(snapshot)) {
-      LOGGER.warn("Snapshot is null, can't get size, return 0 instead.");
-      return 0;
-    }
-    return snapshot.size();
+    return Optional.ofNullable(takeSnapshot()).map(HistogramSnapshot::size).orElse(0);
   }
 
   @Override
   public double get50thPercentile() {
-    HistogramSnapshot snapshot = this.takeSnapshot();
-    if (Objects.isNull(snapshot)) {
-      LOGGER.warn("Snapshot is null, can't get 50th percentile, return 0.0 instead.");
-      return 0;
-    }
-    return snapshot.getValue(0.5);
+    return Optional.ofNullable(takeSnapshot())
+        .map(histogramSnapshot -> histogramSnapshot.getValue(0.5))
+        .orElse(0.0);
   }
 
   @Override
   public double get99thPercentile() {
-    HistogramSnapshot snapshot = this.takeSnapshot();
-    if (Objects.isNull(snapshot)) {
-      LOGGER.warn("Snapshot is null, can't get 99th percentile, return 0.0 instead.");
-      return 0;
-    }
-    return snapshot.getValue(0.99);
+    return Optional.ofNullable(takeSnapshot())
+        .map(histogramSnapshot -> histogramSnapshot.getValue(0.99))
+        .orElse(0.0);
   }
 
   @Override
diff --git a/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/reporter/prometheus/PrometheusReporter.java b/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/reporter/prometheus/PrometheusReporter.java
index c5fffe30c9a2..08f1e7becd77 100644
--- a/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/reporter/prometheus/PrometheusReporter.java
+++ b/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/reporter/prometheus/PrometheusReporter.java
@@ -146,7 +146,8 @@ private String scrape() {
           Timer timer = (Timer) metric;
           HistogramSnapshot snapshot = timer.takeSnapshot();
           if (Objects.isNull(snapshot)) {
-            LOGGER.warn("Detected an error when taking snapshot, will discard this metric");
+            LOGGER.warn(
+                "Detected an error when taking metric timer snapshot, will discard this metric");
             continue;
           }
           name += "_seconds";