fix: use Stopwatch for INFO durations (#1771) (#1779)

Co-authored-by: Nikolay Zdravkov <unsafeptr@gmail.com>
Co-authored-by: Badrish Chandramouli <badrishc@microsoft.com>

Author: 3 people

libs/cluster/Server/Replication/ReplicationManager.cs

@@ -34,11 +34,11 @@ internal sealed partial class ReplicationManager : IDisposable
         readonly ILogger logger;
         bool _disposed;
 
-        private long primary_sync_last_time;
+        private long primary_sync_last_timestamp;
 
-        internal long LastPrimarySyncSeconds => IsRecovering ? (DateTime.UtcNow.Ticks - primary_sync_last_time) / TimeSpan.TicksPerSecond : 0;
+        internal long LastPrimarySyncSeconds => IsRecovering ? (long)Stopwatch.GetElapsedTime(primary_sync_last_timestamp).TotalSeconds : 0;
 
-        internal void UpdateLastPrimarySyncTime() => this.primary_sync_last_time = DateTime.UtcNow.Ticks;
+        internal void UpdateLastPrimarySyncTime() => this.primary_sync_last_timestamp = Stopwatch.GetTimestamp();
 
         private SingleWriterMultiReaderLock recoverLock;
         private SingleWriterMultiReaderLock recoveryStateChangeLock;

libs/server/Metrics/Info/GarnetInfoMetrics.cs

@@ -48,7 +48,7 @@ class GarnetInfoMetrics
 
         private void PopulateServerInfo(StoreWrapper storeWrapper)
         {
-            var uptime = TimeSpan.FromTicks(DateTimeOffset.UtcNow.Ticks - storeWrapper.startupTime);
+            var uptime = Stopwatch.GetElapsedTime(storeWrapper.startupTimestamp);
             serverInfo =
             [
                 new("garnet_version", storeWrapper.version),

libs/server/StoreWrapper.cs

@@ -28,7 +28,7 @@ public sealed class StoreWrapper
         internal readonly string version;
         internal readonly string redisProtocolVersion;
         readonly IGarnetServer[] servers;
-        internal readonly long startupTime;
+        internal readonly long startupTimestamp;
 
         /// <summary>
         /// Default database (DB 0)
@@ -205,7 +205,7 @@ public StoreWrapper(
             this.version = version;
             this.redisProtocolVersion = redisProtocolVersion;
             this.servers = servers;
-            this.startupTime = DateTimeOffset.UtcNow.Ticks;
+            this.startupTimestamp = Stopwatch.GetTimestamp();
             this.serverOptions = serverOptions;
             this.subscribeBroker = subscribeBroker;
             this.customCommandManager = customCommandManager;

test/Garnet.test/RespInfoTests.cs

@@ -75,6 +75,24 @@ public void ResetStatsTest()
             ClassicAssert.AreEqual("total_found:1", totalFound, "Expected total_found to be one after sending one successful request");
         }
 
+        [Test]
+        public void UptimeIncreasesAcrossInfoCalls()
+        {
+            using var redis = ConnectionMultiplexer.Connect(TestUtils.GetConfig());
+            var db = redis.GetDatabase(0);
+
+            static long ParseUptime(string info) =>
+                long.Parse(info.Split("\r\n").First(x => x.StartsWith("uptime_in_seconds:")).Split(':')[1]);
+
+            var first = ParseUptime(db.Execute("INFO", "SERVER").ToString());
+            ClassicAssert.GreaterOrEqual(first, 0);
+
+            Thread.Sleep(TimeSpan.FromSeconds(1.1));
+
+            var second = ParseUptime(db.Execute("INFO", "SERVER").ToString());
+            ClassicAssert.Greater(second, first, "uptime_in_seconds should increase between INFO calls");
+        }
+
         [Test]
         [TestCase("ALL")]
         [TestCase("DEFAULT")]