diff --git a/src/metrics/core.rs b/src/metrics/core.rs
index 23be2fd6..ec17d75a 100644
--- a/src/metrics/core.rs
+++ b/src/metrics/core.rs
@@ -187,7 +187,7 @@ impl MetricsManager {
     fn load_sys_metrics(&mut self) {
         self.system.refresh_all();
         if let Some(process) = self.system.process(Pid::from_u32(self.current_process_id)) {
-            let cpu_usage = process.cpu_usage() as f32;
+            let cpu_usage = process.cpu_usage();
             let rss = process.memory() as f32 / (1024.0 * 1024.0);
             let vms = process.virtual_memory() as f32 / (1024.0 * 1024.0);
             let rss_usage = rss / self.total_memory * 100.0;
diff --git a/src/metrics/timeline/model.rs b/src/metrics/timeline/model.rs
index 78baba92..ec5f0055 100644
--- a/src/metrics/timeline/model.rs
+++ b/src/metrics/timeline/model.rs
@@ -1,8 +1,5 @@
 use crate::metrics::metrics_key::MetricsKey;
-use crate::metrics::model::{
-    CounterValue, GaugeValue, HistogramValue, HistogramValueFmtWrap, SummaryValue,
-    SummaryValueFmtWrap,
-};
+use crate::metrics::model::{CounterValue, GaugeValue, HistogramValue, SummaryValue};
 use crate::metrics::summary::DEFAULT_SUMMARY_BOUNDS;
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
@@ -46,7 +43,7 @@ impl TimelineGroupType {
         match self {
             TimelineGroupType::Least => 0,
             TimelineGroupType::Minute => 60_000,
-            TimelineGroupType::Hour => 3600_000,
+            TimelineGroupType::Hour => 3_600_000,
         }
     }
 
diff --git a/src/naming/core.rs b/src/naming/core.rs
index 771d1f67..89744bb7 100644
--- a/src/naming/core.rs
+++ b/src/naming/core.rs
@@ -614,7 +614,11 @@ impl NamingActor {
         page_index: usize,
         key: &ServiceKey,
     ) -> (usize, Vec<Arc<String>>) {
-        let offset = page_size * max(page_index - 1, 0);
+        let offset = if page_index == 0 {
+            0
+        } else {
+            page_size * (page_index - 1)
+        };
         let param = ServiceQueryParam {
             offset,
             limit: page_size,
diff --git a/src/naming/mod.rs b/src/naming/mod.rs
index bfc9236d..bba198c8 100644
--- a/src/naming/mod.rs
+++ b/src/naming/mod.rs
@@ -113,7 +113,7 @@ impl NamingUtils {
                 ));
             }
             metadata.insert(
-                kv.get(0).unwrap().to_string(),
+                kv.first().unwrap().to_string(),
                 kv.get(1).unwrap().to_string(),
             );
         }