Reduce metrics overhead and cache sysstat days

app/Models/ServerProcess.php

@@ -8,6 +8,8 @@ use Illuminate\Database\Eloquent\Model;
 
 class ServerProcess extends Model
 {
+    protected static ?string $latestBatchIdCache = null;
+
     protected $fillable = [
         'batch_id',
         'rank',
@@ -27,9 +29,11 @@ class ServerProcess extends Model
 
     public function scopeLatestBatch($query)
     {
-        $latestBatchId = static::orderBy('captured_at', 'desc')->value('batch_id');
+        if (static::$latestBatchIdCache === null) {
+            static::$latestBatchIdCache = static::orderBy('captured_at', 'desc')->value('batch_id');
+        }
 
-        return $query->where('batch_id', $latestBatchId);
+        return $query->where('batch_id', static::$latestBatchIdCache);
     }
 
     public static function captureProcesses(array $processes, int $total = 0): string
@@ -44,11 +48,16 @@ class ServerProcess extends Model
             ->limit(10)
             ->pluck('batch_id');
 
-        static::whereNotIn('batch_id', $keepBatches)->delete();
+        if ($keepBatches->isNotEmpty()) {
+            static::whereNotIn('batch_id', $keepBatches)->delete();
+        }
+
+        static::$latestBatchIdCache = $batchId;
 
         // Insert new processes
+        $rows = [];
         foreach ($processes as $index => $proc) {
-            static::create([
+            $rows[] = [
                 'batch_id' => $batchId,
                 'rank' => $index + 1,
                 'pid' => $proc['pid'] ?? 0,
@@ -57,7 +66,11 @@ class ServerProcess extends Model
                 'cpu' => $proc['cpu'] ?? 0,
                 'memory' => $proc['memory'] ?? 0,
                 'captured_at' => $now,
-            ]);
+            ];
+        }
+
+        if ($rows) {
+            static::insert($rows);
         }
 
         return $batchId;

app/Services/SysstatMetrics.php

@@ -95,6 +95,9 @@ class SysstatMetrics
         $samples = [];
         $current = $start->startOfDay();
         $lastDay = $end->startOfDay();
+        $startTimestamp = $start->getTimestamp();
+        $endTimestamp = $end->getTimestamp();
+        $useDailyCache = ($endTimestamp - $startTimestamp) > 21600;
 
         while ($current <= $lastDay) {
             $fileLong = sprintf('/var/log/sysstat/sa%s', $current->format('Ymd'));
@@ -106,15 +109,22 @@ class SysstatMetrics
                 continue;
             }
 
-            $dayStart = $current->isSameDay($start) ? $start : $current->startOfDay();
+            if ($useDailyCache) {
-            $dayEnd = $current->isSameDay($end) ? $end : $current->endOfDay();
+                $statistics = $this->readSadfDay($file, $current, $options);
-            $statistics = $this->readSadf($file, $dayStart, $dayEnd, $options);
+            } else {
+                $dayStart = $current->isSameDay($start) ? $start : $current->startOfDay();
+                $dayEnd = $current->isSameDay($end) ? $end : $current->endOfDay();
+                $statistics = $this->readSadf($file, $dayStart, $dayEnd, $options);
+            }
 
             foreach ($statistics as $stat) {
                 $parsed = $this->parseSample($stat);
                 if ($parsed === null) {
                     continue;
                 }
+                if ($parsed['timestamp'] < $startTimestamp || $parsed['timestamp'] > $endTimestamp) {
+                    continue;
+                }
                 $samples[] = $parsed;
             }
 
@@ -148,6 +158,8 @@ class SysstatMetrics
             ],
         );
         $process = new Process($args);
+        $process->setTimeout(8);
+        $process->setIdleTimeout(5);
         $process->run();
 
         if (! $process->isSuccessful()) {
@@ -167,6 +179,23 @@ class SysstatMetrics
         return $stats;
     }
 
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function readSadfDay(string $file, CarbonImmutable $day, array $options): array
+    {
+        $mtime = @filemtime($file) ?: 0;
+        $optionsKey = implode(',', $options);
+        $cacheKey = sprintf('sysstat.sadf.day.%s.%d.%s', md5($file), $mtime, md5($optionsKey));
+
+        return Cache::remember($cacheKey, now()->addMinutes(10), function () use ($file, $day, $options): array {
+            $dayStart = $day->startOfDay();
+            $dayEnd = $day->endOfDay();
+
+            return $this->readSadf($file, $dayStart, $dayEnd, $options);
+        });
+    }
+
     /**
      * @return array<int, string>
      */