Add jitter to renewal time calculation (Azure#49079)

Author: JoshLove-msft

sdk/servicebus/Azure.Messaging.ServiceBus/CHANGELOG.md

@@ -10,6 +10,8 @@
 
 ### Other Changes
 
+- Added jitter to the lock renewal timer to reduce the likelihood of lock renewal collisions when using the `ServiceBusProcessor` or the `ServiceBusSessionProcessor`.
+
 ## 7.18.4 (2025-02-11)
 
 ### Bugs Fixed

sdk/servicebus/Azure.Messaging.ServiceBus/src/Processor/ReceiverManager.cs

@@ -29,6 +29,9 @@ internal class ReceiverManager
         protected readonly ServiceBusProcessorOptions ProcessorOptions;
         private readonly MessagingClientDiagnostics _clientDiagnostics;
 
+        private static int s_randomSeed = Environment.TickCount;
+        private static readonly ThreadLocal<Random> RandomNumberGenerator = new ThreadLocal<Random>(() => new Random(Interlocked.Increment(ref s_randomSeed)), false);
+
         protected bool AutoRenewLock => ProcessorOptions.MaxAutoLockRenewalDuration > TimeSpan.Zero ||
                                         ProcessorOptions.MaxAutoLockRenewalDuration == Timeout.InfiniteTimeSpan;
 
@@ -397,17 +400,15 @@ protected virtual async Task RaiseExceptionReceived(ProcessErrorEventArgs eventA
 
         protected static TimeSpan CalculateRenewDelay(DateTimeOffset lockedUntil)
         {
-            var remainingTime = lockedUntil - DateTimeOffset.UtcNow;
+            var shortJitter = TimeSpan.FromMilliseconds(RandomNumberGenerator.Value.Next(0, 50));
+            var longJitter = TimeSpan.FromMilliseconds(RandomNumberGenerator.Value.Next(0, 200));
 
-            if (remainingTime < TimeSpan.FromMilliseconds(400))
-            {
-                return TimeSpan.Zero;
-            }
+            var remainingTime = lockedUntil - DateTimeOffset.UtcNow;
 
             var buffer = TimeSpan.FromTicks(Math.Min(remainingTime.Ticks / 2, Constants.MaximumRenewBufferDuration.Ticks));
-            var renewAfter = remainingTime - buffer;
+            var renewAfter = remainingTime - buffer - longJitter;
 
-            return renewAfter;
+            return renewAfter < TimeSpan.FromMilliseconds(400) ? shortJitter : renewAfter;
         }
     }
 }