diff --git a/public/js/chart.js b/public/js/chart.js
index 6467e8a..38e8b1e 100644
--- a/public/js/chart.js
+++ b/public/js/chart.js
@@ -30,7 +30,23 @@ class AreaChart {
   }
 
   setData(data) {
-    this.data = data;
+    if (!data || !data.timestamps) return;
+    
+    // Downsample if data is too dense (target ~1500 points for performance)
+    const MAX_POINTS = 1500;
+    if (data.timestamps.length > MAX_POINTS) {
+      const skip = Math.ceil(data.timestamps.length / MAX_POINTS);
+      const downsampled = { timestamps: [], rx: [], tx: [] };
+      for (let i = 0; i < data.timestamps.length; i += skip) {
+        downsampled.timestamps.push(data.timestamps[i]);
+        downsampled.rx.push(data.rx[i]);
+        downsampled.tx.push(data.tx[i]);
+      }
+      this.data = downsampled;
+    } else {
+      this.data = data;
+    }
+
     this.animProgress = 0;
     this.animate();
   }
@@ -132,16 +148,22 @@ class AreaChart {
   drawArea(ctx, values, getX, getY, chartH, p, fillColorTop, fillColorBottom, strokeColor, len) {
     if (!values || values.length === 0) return;
 
+    const useSimple = len > 500;
+
     // Fill
     ctx.beginPath();
     ctx.moveTo(getX(0), getY(values[0] || 0));
     for (let i = 1; i < len; i++) {
-      const prevX = getX(i - 1);
-      const currX = getX(i);
-      const prevY = getY(values[i - 1] || 0);
-      const currY = getY(values[i] || 0);
-      const midX = (prevX + currX) / 2;
-      ctx.bezierCurveTo(midX, prevY, midX, currY, currX, currY);
+      if (useSimple) {
+        ctx.lineTo(getX(i), getY(values[i] || 0));
+      } else {
+        const prevX = getX(i - 1);
+        const currX = getX(i);
+        const prevY = getY(values[i - 1] || 0);
+        const currY = getY(values[i] || 0);
+        const midX = (prevX + currX) / 2;
+        ctx.bezierCurveTo(midX, prevY, midX, currY, currX, currY);
+      }
     }
     ctx.lineTo(getX(len - 1), p.top + chartH);
     ctx.lineTo(getX(0), p.top + chartH);
@@ -157,15 +179,20 @@ class AreaChart {
     ctx.beginPath();
     ctx.moveTo(getX(0), getY(values[0] || 0));
     for (let i = 1; i < len; i++) {
-      const prevX = getX(i - 1);
-      const currX = getX(i);
-      const prevY = getY(values[i - 1] || 0);
-      const currY = getY(values[i] || 0);
-      const midX = (prevX + currX) / 2;
-      ctx.bezierCurveTo(midX, prevY, midX, currY, currX, currY);
+      if (useSimple) {
+        ctx.lineTo(getX(i), getY(values[i] || 0));
+      } else {
+        const prevX = getX(i - 1);
+        const currX = getX(i);
+        const prevY = getY(values[i - 1] || 0);
+        const currY = getY(values[i] || 0);
+        const midX = (prevX + currX) / 2;
+        ctx.bezierCurveTo(midX, prevY, midX, currY, currX, currY);
+      }
     }
     ctx.strokeStyle = strokeColor;
     ctx.lineWidth = 2;
+    ctx.lineJoin = 'round';
     ctx.stroke();
   }
 
diff --git a/server/index.js b/server/index.js
index 2bb5bee..fde6cb3 100644
--- a/server/index.js
+++ b/server/index.js
@@ -659,8 +659,8 @@ checkAndFixDatabase().then(() => {
   initialPreload();
 });
 
-// Record traffic every 5 minutes
-setInterval(recordTrafficStats, 5 * 60 * 1000);
+// Record traffic every 5 seconds (17,280 points/day)
+setInterval(recordTrafficStats, 5 * 1000);
 // Initial record after a short delay
 setTimeout(recordTrafficStats, 10000);
 
diff --git a/server/prometheus-service.js b/server/prometheus-service.js
index c5f5fc1..a740bbb 100644
--- a/server/prometheus-service.js
+++ b/server/prometheus-service.js
@@ -172,7 +172,8 @@ async function getOverviewMetrics(url, sourceName) {
     // Total traffic transmitted in last 24h
     query(url, 'sum by (instance, job) (increase(node_network_transmit_bytes_total{device!~"lo|veth.*|docker.*|br-.*"}[24h]))').catch(() => []),
     // Up instances (at least one successful scrape in last 5m)
-    query(url, 'max_over_time(up{job=~".*node.*|.*exporter.*"}[5m])').catch(() => [])
+    // We broaden the job filter to catch more variations of node-exporter jobs
+    query(url, 'max_over_time(up{job=~".*node.*|.*exporter.*|.*host.*"}[5m])').catch(() => [])
   ]);
 
   // Build per-instance data map
@@ -252,6 +253,14 @@ async function getOverviewMetrics(url, sourceName) {
     inst.netTx = parseFloat(r.value[1]) || 0;
   }
 
+  // Final check: If an instance has non-zero CPU or Memory total data but is marked offline, 
+  // it means we missed its 'up' metric due to job labels, but it's clearly sending data.
+  for (const inst of instances.values()) {
+    if (!inst.up && (inst.cpuPercent > 0 || inst.memTotal > 0)) {
+      inst.up = true;
+    }
+  }
+
   // Aggregate
   let totalCpuUsed = 0, totalCpuCores = 0;
   let totalMemUsed = 0, totalMemTotal = 0;
@@ -408,7 +417,7 @@ function mergeCpuHistories(histories) {
 async function getTrafficHistoryRange(url) {
   const now = Math.floor(Date.now() / 1000);
   const start = now - 86400; // 24h ago
-  const step = 300; // 5 minutes
+  const step = 5; // 5 seconds (17,280 points for 24h)
 
   const queries = [
     'sum(node_network_receive_bytes_total{device!~"lo|veth.*|docker.*|br-.*"})',