Handling SQL Server Deadlocks in Entity Framework Core 6 with C#
I'm sure I'm missing something obvious here, but I'm currently working on a C# application that uses Entity Framework Core 6 to interact with a SQL Server database. I’ve recently encountered a persistent deadlock situation while performing concurrent updates on the same table from multiple threads. The error message I'm receiving is: `Transaction (Process ID 55) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction.` To troubleshoot, I've implemented the following retry logic in my repository method: ```csharp public async Task UpdateEntityAsync(MyEntity entity) { bool success = false; int attempts = 0; const int maxAttempts = 3; while (!success && attempts < maxAttempts) { try { _context.MyEntities.Update(entity); await _context.SaveChangesAsync(); success = true; } catch (DbUpdateException ex) when (IsDeadlockException(ex)) { attempts++; if (attempts >= maxAttempts) { throw; // Rethrow after max attempts } // Optionally add a delay here before retrying await Task.Delay(100); } } } private bool IsDeadlockException(DbUpdateException ex) { // Check the exception for deadlock related SQL error codes return ex.InnerException is SqlException sqlEx && sqlEx.Number == 1205; } ``` However, I'm still seeing deadlocks occurring frequently. I've also ensured that all my database operations are wrapped within a transaction scope. I'm considering the following approaches to reduce deadlocks: 1. **Reducing transaction duration**: Is there a recommended way to minimize the time each transaction holds locks? 2. **Optimistic Concurrency**: Should I switch to using optimistic concurrency control? 3. **Transaction Isolation Levels**: Can altering the isolation level help, and if so, what level should I consider? Any insights on best practices or additional strategies to mitigate deadlocks in this scenario would be greatly appreciated! For context: I'm using C# on Linux. Am I missing something obvious?