feat: add StatusDelayProfile with status-based backoff logic

Author: LiamHamsters

src/Ydb.Sdk/src/Ado/Retry/DefaultRetryPolicy.cs

@@ -1,27 +1,18 @@
-using System.Data;
-using System.Data.Common;
-
 namespace Ydb.Sdk.Ado.Retry;
 
 public sealed class DefaultRetryPolicy : IRetryPolicy
 {
     private readonly RetryConfig _cfg;
 
-    public DefaultRetryPolicy(RetryConfig? config = null) => _cfg = config ?? new RetryConfig();
+    public DefaultRetryPolicy(RetryConfig? config = null)
+        => _cfg = config ?? new RetryConfig();
 
     public int MaxAttempts => _cfg.MaxAttempts;
 
-    public bool IsStreaming(DbCommand command, CommandBehavior behavior) => _cfg.IsStreaming(command, behavior);
-
     public bool CanRetry(Exception ex, bool isIdempotent)
     {
-        if (TryUnwrapYdbException(ex, out var ydb))
-        {
+        if (ex is YdbException ydb)
             return isIdempotent ? ydb.IsTransientWhenIdempotent : ydb.IsTransient;
-        }
-
-        if (ex is TimeoutException) return true;
-        if (ex is OperationCanceledException oce && !oce.CancellationToken.IsCancellationRequested) return true;
 
         return false;
     }
@@ -30,28 +21,19 @@ public bool CanRetry(Exception ex, bool isIdempotent)
     {
         if (attempt <= 0) attempt = 1;
 
-        if (TryUnwrapYdbException(ex, out var ydb))
+        if (ex is YdbException ydb)
         {
             if (_cfg.PerStatusDelay.TryGetValue(ydb.Code, out var calc))
                 return Cap(calc(attempt));
+
+            var profileDelay = _cfg.StatusDelayProfile.GetDelay(ydb.Code, attempt);
+            if (profileDelay is not null)
+                return Cap(profileDelay);
         }
 
         return Cap(_cfg.DefaultDelay(ex, attempt));
     }
 
-    private static bool TryUnwrapYdbException(Exception ex, out YdbException ydb)
-    {
-        for (var e = ex; e is not null; e = e.InnerException!)
-        {
-            if (e is YdbException yy)
-            {
-                ydb = yy; return true;
-            }
-        }
-        ydb = null!;
-        return false;
-    }
-
     private TimeSpan? Cap(TimeSpan? delay)
     {
         if (delay is null) return null;

src/Ydb.Sdk/src/Ado/Retry/Delay/DefaultStatusDelayProfile.cs

@@ -0,0 +1,34 @@
+namespace Ydb.Sdk.Ado.Retry.Delay;
+
+public sealed class DefaultStatusDelayProfile : IStatusDelayProfile
+{
+    public TimeSpan? GetDelay(StatusCode code, int attempt)
+    {
+        TimeSpan Calc(TimeSpan baseDelay)
+        {
+            var baseMs = baseDelay.TotalMilliseconds * Math.Pow(2.0, attempt - 1);
+            var jitter = 1.0 + (Random.Shared.NextDouble() * 0.5);
+            var ms = Math.Min(baseMs * jitter, TimeSpan.FromSeconds(10).TotalMilliseconds);
+            return TimeSpan.FromMilliseconds(ms);
+        }
+
+        switch (code)
+        {
+            case StatusCode.BadSession:
+                return TimeSpan.Zero;
+            case StatusCode.Aborted:
+            case StatusCode.Unavailable:
+            case StatusCode.SessionBusy:
+            case StatusCode.ClientInternalError:
+            case StatusCode.ClientTransportUnavailable:
+            case StatusCode.ClientTransportTimeout:
+                return Calc(TimeSpan.FromMilliseconds(100));
+            case StatusCode.Overloaded:
+            case StatusCode.ClientResourceExhausted:
+            case StatusCode.ClientTransportResourceExhausted:
+                return Calc(TimeSpan.FromMilliseconds(500));
+            default:
+                return null;
+        }
+    }
+}

src/Ydb.Sdk/src/Ado/Retry/Delay/IStatusDelayProfile.cs

@@ -0,0 +1,6 @@
+namespace Ydb.Sdk.Ado.Retry.Delay;
+
+public interface IStatusDelayProfile
+{
+    TimeSpan? GetDelay(StatusCode code, int attempt);
+}

src/Ydb.Sdk/src/Ado/Retry/IRetryPolicy.cs

@@ -1,5 +1,3 @@
-using System.Data.Common;
-
 namespace Ydb.Sdk.Ado.Retry;
 
 public interface IRetryPolicy
@@ -9,6 +7,4 @@ public interface IRetryPolicy
     bool CanRetry(Exception ex, bool isIdempotent);
 
     TimeSpan? GetDelay(Exception ex, int attempt);
-
-    bool IsStreaming(DbCommand command, System.Data.CommandBehavior behavior);
 }

src/Ydb.Sdk/src/Ado/Retry/RetryConfig.cs

@@ -1,3 +1,5 @@
+using Ydb.Sdk.Ado.Retry.Delay;
+
 namespace Ydb.Sdk.Ado.Retry;
 
 public sealed class RetryConfig
@@ -14,12 +16,10 @@ public sealed class RetryConfig
 
     public Dictionary<StatusCode, Func<int, TimeSpan?>> PerStatusDelay { get; } = new();
 
-    public Func<System.Data.Common.DbCommand, System.Data.CommandBehavior, bool> IsStreaming { get; set; }
-        = static (_, behavior) => (behavior & System.Data.CommandBehavior.SequentialAccess) != 0;
-
-    public Func<Exception, int, TimeSpan?> DefaultDelay { get; set; }
+    public IStatusDelayProfile StatusDelayProfile { get; set; } = new DefaultStatusDelayProfile();
 
-        = static (ex, attempt) =>
+    public Func<Exception, int, TimeSpan?> DefaultDelay { get; set; } =
+        static (_, attempt) =>
         {
             var baseMs = 100.0 * Math.Pow(2.0, Math.Max(0, attempt - 1));
             var jitter = 1.0 + (Random.Shared.NextDouble() * 0.5);

src/Ydb.Sdk/test/Ydb.Sdk.Ado.Tests/DefaultRetryPolicyTests.cs

@@ -98,26 +98,6 @@ public void CanRetry_WhenUserCancelled_ReturnsFalse()
         var ex = new OperationCanceledException(cts.Token);
         Assert.False(policy.CanRetry(ex, isIdempotent: true));
     }
-
-    [Fact]
-    public void IsStreaming_WhenSequentialAccess_ReturnsTrue()
-    {
-        var config = new RetryConfig();
-        var policy = new DefaultRetryPolicy(config);
-        var cmd = new DummyCommand();
-
-        Assert.True(policy.IsStreaming(cmd, CommandBehavior.SequentialAccess));
-    }
-
-    [Fact]
-    public void IsStreaming_WhenCustomConfigDelegateUsed_ReturnsTrue()
-    {
-        var config = new RetryConfig { IsStreaming = (c, b) => true };
-        var policy = new DefaultRetryPolicy(config);
-        var cmd = new DummyCommand();
-
-        Assert.True(policy.IsStreaming(cmd, CommandBehavior.Default));
-    }
 
     [Fact]
     public void GetDelay_WhenDelayExceedsMaxDelay_IsCappedToMaxDelay()