fix: implement exponential backoff strategy for concurrency exceptions in SaveChangesAsync

src/Jellyfin.Database/Jellyfin.Database.Implementations/JellyfinDbContext.cs

@@ -352,10 +352,17 @@ public class JellyfinDbContext(DbContextOptions<JellyfinDbContext> options, ILog
         }
         catch (DbUpdateConcurrencyException ex)
         {
-            // When marking items as played in quick succession, concurrency conflicts can occur.
+            // Concurrency conflicts can occur when marking items as played in quick succession.
-            // To resolve this, we'll reload the conflicting entities from the database and retry.
+            // To resolve this, we'll retry the operation with an exponential backoff strategy.
-            logger.LogWarning(ex, "Concurrency exception, retrying operation.");
+            logger.LogWarning(ex, "Concurrency exception, retrying operation with exponential backoff.");
 
+            var maxRetries = 3;
+            var delay = TimeSpan.FromMilliseconds(100);
+
+            for (var i = 0; i < maxRetries; i++)
+            {
+                try
+                {
                     foreach (var entry in ex.Entries)
                     {
                         // Reload the entity from the database to get the latest version
@@ -365,6 +372,17 @@ public class JellyfinDbContext(DbContextOptions<JellyfinDbContext> options, ILog
                     // Retry saving changes after resolving conflicts
                     return await base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken).ConfigureAwait(false);
                 }
+                catch (DbUpdateConcurrencyException retryEx) when (i < maxRetries - 1)
+                {
+                    logger.LogWarning(retryEx, "Concurrency exception on retry {RetryCount}, delaying for {Delay}ms.", i + 1, delay.TotalMilliseconds);
+                    await Task.Delay(delay, cancellationToken).ConfigureAwait(false);
+                    delay *= 2; // Exponential backoff
+                }
+            }
+
+            // If all retries fail, rethrow the last exception
+            throw;
+        }
         catch (DbUpdateException ex)
         {
             // Check if it's a constraint violation (works across all database providers)