CSHARP-3757: Redirect read/write retries to other mongos if possible

src/MongoDB.Driver.Core/Core/Bindings/ChannelReadBinding.cs

@@ -14,10 +14,9 @@
 */
 
 using System;
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
-using MongoDB.Driver.Core.Clusters;
-using MongoDB.Driver.Core.Connections;
 using MongoDB.Driver.Core.Misc;
 using MongoDB.Driver.Core.Servers;
 
@@ -51,7 +50,7 @@ public ChannelReadBinding(IServer server, IChannelHandle channel, ReadPreference
             _session = Ensure.IsNotNull(session, nameof(session));
         }
 
-        // properties        
+        // properties
         /// <inheritdoc/>
         public ReadPreference ReadPreference
         {
@@ -90,6 +89,18 @@ public Task<IChannelSourceHandle> GetReadChannelSourceAsync(CancellationToken ca
             return Task.FromResult<IChannelSourceHandle>(GetReadChannelSourceHelper());
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetReadChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetReadChannelSource(cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetReadChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetReadChannelSourceAsync(cancellationToken);
+        }
+
         private IChannelSourceHandle GetReadChannelSourceHelper()
         {
             return new ChannelSourceHandle(new ChannelChannelSource(_server, _channel.Fork(), _session.Fork()));

src/MongoDB.Driver.Core/Core/Bindings/ChannelReadWriteBinding.cs

@@ -14,6 +14,7 @@
 */
 
 using System;
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MongoDB.Driver.Core.Misc;
@@ -85,32 +86,68 @@ public Task<IChannelSourceHandle> GetReadChannelSourceAsync(CancellationToken ca
             return Task.FromResult(GetChannelSourceHelper());
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetReadChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetReadChannelSource(cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetReadChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetReadChannelSourceAsync(cancellationToken);
+        }
+
         /// <inheritdoc/>
         public IChannelSourceHandle GetWriteChannelSource(CancellationToken cancellationToken)
         {
             ThrowIfDisposed();
             return GetChannelSourceHelper();
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetWriteChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSource(cancellationToken);
+        }
+
         /// <inheritdoc/>
         public IChannelSourceHandle GetWriteChannelSource(IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
         {
             return GetWriteChannelSource(cancellationToken); // ignore mayUseSecondary
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetWriteChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSource(mayUseSecondary, cancellationToken);
+        }
+
         /// <inheritdoc/>
         public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(CancellationToken cancellationToken)
         {
             ThrowIfDisposed();
             return Task.FromResult(GetChannelSourceHelper());
         }
 
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSourceAsync(cancellationToken);
+        }
+
         /// <inheritdoc/>
         public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
         {
             return GetWriteChannelSourceAsync(cancellationToken); // ignore mayUseSecondary
         }
 
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSourceAsync(mayUseSecondary, cancellationToken);
+        }
+
         // private methods
         private IChannelSourceHandle GetChannelSourceHelper()
         {

src/MongoDB.Driver.Core/Core/Bindings/ChannelSourceReadWriteBinding.cs

@@ -14,9 +14,11 @@
 */
 
 using System;
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MongoDB.Driver.Core.Misc;
+using MongoDB.Driver.Core.Servers;
 
 namespace MongoDB.Driver.Core.Bindings
 {
@@ -73,32 +75,68 @@ public Task<IChannelSourceHandle> GetReadChannelSourceAsync(CancellationToken ca
             return Task.FromResult(GetChannelSourceHelper());
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetReadChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetReadChannelSource(cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetReadChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetReadChannelSourceAsync(cancellationToken);
+        }
+
         /// <inheritdoc/>
         public IChannelSourceHandle GetWriteChannelSource(CancellationToken cancellationToken)
         {
             ThrowIfDisposed();
             return GetChannelSourceHelper();
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetWriteChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSource(cancellationToken);
+        }
+
         /// <inheritdoc/>
         public IChannelSourceHandle GetWriteChannelSource(IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
         {
             return GetWriteChannelSource(cancellationToken); // ignore mayUseSecondary
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetWriteChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSource(mayUseSecondary, cancellationToken);
+        }
+
         /// <inheritdoc/>
         public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(CancellationToken cancellationToken)
         {
             ThrowIfDisposed();
             return Task.FromResult(GetChannelSourceHelper());
         }
 
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSourceAsync(cancellationToken);
+        }
+
         /// <inheritdoc/>
         public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
         {
             return GetWriteChannelSourceAsync(cancellationToken); // ignore mayUseSecondary
         }
 
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken)
+        {
+            return GetWriteChannelSourceAsync(mayUseSecondary, cancellationToken);
+        }
+
         /// <inheritdoc/>
         public void Dispose()
         {

src/MongoDB.Driver.Core/Core/Bindings/IBinding.cs

@@ -14,6 +14,7 @@
 */
 
 using System;
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MongoDB.Driver.Core.Servers;
@@ -61,6 +62,22 @@ public interface IReadBinding : IBinding
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>A channel source.</returns>
         Task<IChannelSourceHandle> GetReadChannelSourceAsync(CancellationToken cancellationToken);
+
+        /// <summary>
+        /// Gets a channel source for read operations while deprioritizing servers in the provided collection.
+        /// </summary>
+        /// <param name="deprioritizedServers">The deprioritized servers.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>A channel source.</returns>
+        IChannelSourceHandle GetReadChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken);
+
+        /// <summary>
+        /// Gets a channel source for read operations while deprioritizing servers in the provided collection.
+        /// </summary>
+        /// <param name="deprioritizedServers">The deprioritized servers.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>A channel source.</returns>
+        Task<IChannelSourceHandle> GetReadChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken);
     }
 
     /// <summary>
@@ -75,6 +92,14 @@ public interface IWriteBinding : IBinding
         /// <returns>A channel source.</returns>
         IChannelSourceHandle GetWriteChannelSource(CancellationToken cancellationToken);
 
+        /// <summary>
+        /// Gets a channel source for write operations while deprioritizing servers in the provided collection.
+        /// </summary>
+        /// <param name="deprioritizedServers">The deprioritized servers.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>A channel source.</returns>
+        IChannelSourceHandle GetWriteChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken);
+
         /// <summary>
         /// Gets a channel source for write operations that may use a secondary.
         /// </summary>
@@ -83,20 +108,46 @@ public interface IWriteBinding : IBinding
         /// <returns>A channel source.</returns>
         IChannelSourceHandle GetWriteChannelSource(IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken);
 
+        /// <summary>
+        /// Gets a channel source for write operations that may use a secondary and deprioritizes servers in the provided collection.
+        /// </summary>
+        /// <param name="deprioritizedServers">The deprioritized servers.</param>
+        /// <param name="mayUseSecondary">The may use secondary criteria.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>A channel source.</returns>
+        IChannelSourceHandle GetWriteChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken);
+
         /// <summary>
         /// Gets a channel source for write operations.
         /// </summary>
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>A channel source.</returns>
         Task<IChannelSourceHandle> GetWriteChannelSourceAsync(CancellationToken cancellationToken);
 
+        /// <summary>
+        /// Gets a channel source for write operations while deprioritizing servers in the provided collection.
+        /// </summary>
+        /// <param name="deprioritizedServers">The deprioritized servers.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>A channel source.</returns>
+        Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken);
+
         /// <summary>
         /// Gets a channel source for write operations that may use a secondary.
         /// </summary>
         /// <param name="mayUseSecondary">The may use secondary criteria.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>A channel source.</returns>
         Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken);
+
+        /// <summary>
+        /// Gets a channel source for write operations that may use a secondary and deprioritizes servers in the provided collection.
+        /// </summary>
+        /// <param name="deprioritizedServers">The deprioritized servers.</param>
+        /// <param name="mayUseSecondary">The may use secondary criteria.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>A channel source.</returns>
+        Task<IChannelSourceHandle> GetWriteChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, IMayUseSecondaryCriteria mayUseSecondary, CancellationToken cancellationToken);
     }
 
     /// <summary>

src/MongoDB.Driver.Core/Core/Bindings/ReadBindingHandle.cs

@@ -15,12 +15,10 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using MongoDB.Driver.Core.Clusters;
 using MongoDB.Driver.Core.Misc;
+using MongoDB.Driver.Core.Servers;
 
 namespace MongoDB.Driver.Core.Bindings
 {
@@ -76,6 +74,20 @@ public Task<IChannelSourceHandle> GetReadChannelSourceAsync(CancellationToken ca
             return _reference.Instance.GetReadChannelSourceAsync(cancellationToken);
         }
 
+        /// <inheritdoc />
+        public IChannelSourceHandle GetReadChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            ThrowIfDisposed();
+            return _reference.Instance.GetReadChannelSource(deprioritizedServers, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public Task<IChannelSourceHandle> GetReadChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            ThrowIfDisposed();
+            return _reference.Instance.GetReadChannelSourceAsync(deprioritizedServers, cancellationToken);
+        }
+
         /// <inheritdoc/>
         public void Dispose()
         {

src/MongoDB.Driver.Core/Core/Bindings/ReadPreferenceBinding.cs

@@ -14,6 +14,7 @@
 */
 
 using System;
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MongoDB.Driver.Core.Clusters;
@@ -67,16 +68,28 @@ public ICoreSessionHandle Session
         /// <inheritdoc/>
         public IChannelSourceHandle GetReadChannelSource(CancellationToken cancellationToken)
         {
-            ThrowIfDisposed();
-            var server = _cluster.SelectServerAndPinIfNeeded(_session, _serverSelector, cancellationToken);
-            return GetChannelSourceHelper(server);
+            return GetReadChannelSource(null, cancellationToken);
         }
 
         /// <inheritdoc/>
         public async Task<IChannelSourceHandle> GetReadChannelSourceAsync(CancellationToken cancellationToken)
+        {
+            return await GetReadChannelSourceAsync(null, cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <inheritdoc />
+        public IChannelSourceHandle GetReadChannelSource(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
+        {
+            ThrowIfDisposed();
+            var server = _cluster.SelectServerAndPinIfNeeded(_session, _serverSelector, deprioritizedServers, cancellationToken);
+            return GetChannelSourceHelper(server);
+        }
+
+        /// <inheritdoc />
+        public async Task<IChannelSourceHandle> GetReadChannelSourceAsync(IReadOnlyCollection<ServerDescription> deprioritizedServers, CancellationToken cancellationToken)
         {
             ThrowIfDisposed();
-            var server = await _cluster.SelectServerAndPinIfNeededAsync(_session, _serverSelector, cancellationToken).ConfigureAwait(false);
+            var server = await _cluster.SelectServerAndPinIfNeededAsync(_session, _serverSelector, deprioritizedServers, cancellationToken).ConfigureAwait(false);
             return GetChannelSourceHelper(server);
         }