fix: prevent database circuit failure storm

src/LiveRecorder.Infrastructure/Persistence/CircuitAwareExecutionStrategy.cs

@@ -74,9 +74,9 @@ public sealed class CircuitAwareExecutionStrategy : NpgsqlRetryingExecutionStrat
             DatabaseCircuitBreaker.RecordSuccess();
             return result;
         }
-        catch
+        catch (Exception ex)
         {
-            DatabaseCircuitBreaker.RecordFailure();
+            DatabaseCircuitBreaker.RecordFailure(ex);
             throw;
         }
     }
@@ -94,9 +94,9 @@ public sealed class CircuitAwareExecutionStrategy : NpgsqlRetryingExecutionStrat
             DatabaseCircuitBreaker.RecordSuccess();
             return result;
         }
-        catch
+        catch (Exception ex)
         {
-            DatabaseCircuitBreaker.RecordFailure();
+            DatabaseCircuitBreaker.RecordFailure(ex);
             throw;
         }
     }

src/LiveRecorder.Infrastructure/Persistence/DatabaseCircuitBreaker.cs

@@ -78,14 +78,27 @@ public static class DatabaseCircuitBreaker
     }
 
     /// <summary>Record a failed database operation.</summary>
-    public static void RecordFailure()
+    public static void RecordFailure(Exception? exception = null)
     {
         lock (Lock)
         {
+            // Rejected requests are not new database failures. Counting them
+            // causes the failure counter and logs to grow without bound.
+            if (exception is DatabaseCircuitOpenException)
+            {
+                return;
+            }
+
+            var now = DateTimeOffset.UtcNow;
+            if (_consecutiveFailures >= FailureThreshold && now - _openedAt <= BreakDuration)
+            {
+                return;
+            }
+
             _consecutiveFailures++;
             if (_consecutiveFailures >= FailureThreshold)
             {
-                _openedAt = DateTimeOffset.UtcNow;
+                _openedAt = now;
             }
         }
     }

src/LiveRecorder.Infrastructure/Services/DriveInfoStorageCapacityProvider.cs

@@ -19,8 +19,10 @@ public sealed class DriveInfoStorageCapacityProvider : IStorageCapacityProvider
                         drive.AvailableFreeSpace));
                 }
             }
-            catch (Exception ex) when (ex is IOException or UnauthorizedAccessException)
+            catch (Exception ex) when (ex is IOException or UnauthorizedAccessException or OverflowException or ArgumentException or NotSupportedException)
             {
+                // Ignore malformed FUSE/cloud mount capacities and continue
+                // looking for the volume that contains the output path.
             }
         }
 

src/LiveRecorder.WebApi/Middleware/ExceptionHandlingMiddleware.cs

@@ -21,10 +21,12 @@ public sealed class ExceptionHandlingMiddleware
         {
             await _next(context);
         }
-        catch (DatabaseCircuitOpenException ex)
+        catch (DatabaseCircuitOpenException)
         {
             // Circuit is open — fast-fail with 503
-            _logger.LogWarning(ex, "Database circuit breaker is open, returning 503");
+            _logger.LogDebug(
+                "Database circuit breaker is open, returning 503. Failures={Failures}",
+                DatabaseCircuitBreaker.ConsecutiveFailures);
             context.Response.StatusCode = StatusCodes.Status503ServiceUnavailable;
             await context.Response.WriteAsJsonAsync(new
             {

tests/LiveRecorder.Tests/DatabaseCircuitBreakerTests.cs

@@ -59,6 +59,23 @@ public sealed class DatabaseCircuitBreakerTests
         Assert.Equal(0, DatabaseCircuitBreaker.ConsecutiveFailures);
     }
 
+    [Fact]
+    public void RecordFailure_while_circuit_is_open_does_not_grow_failure_counter()
+    {
+        for (var i = 0; i < FailureThreshold; i++)
+        {
+            DatabaseCircuitBreaker.RecordFailure();
+        }
+
+        Assert.True(DatabaseCircuitBreaker.IsOpen);
+        var failures = DatabaseCircuitBreaker.ConsecutiveFailures;
+
+        DatabaseCircuitBreaker.RecordFailure();
+        DatabaseCircuitBreaker.RecordFailure(new DatabaseCircuitOpenException("already open"));
+
+        Assert.Equal(failures, DatabaseCircuitBreaker.ConsecutiveFailures);
+    }
+
     [Fact]
     public void IsOpen_after_break_duration_transitions_to_half_open()
     {