feat: blue/green support

AwsWrapperDataProvider/AwsWrapperConnection.cs

@@ -39,7 +39,7 @@ public class AwsWrapperConnection : DbConnection, IWrapper
 
     private bool deferredInitialization = false;
 
-    internal ConnectionPluginManager? PluginManager { get; private set; }
+    public ConnectionPluginManager? PluginManager { get; private set; }
 
     internal Dictionary<string, string>? ConnectionProperties { get; private set; }
 

AwsWrapperDataProvider/Driver/ConnectionPluginManager.cs

@@ -20,14 +20,17 @@
 using AwsWrapperDataProvider.Driver.HostInfo;
 using AwsWrapperDataProvider.Driver.HostListProviders;
 using AwsWrapperDataProvider.Driver.Plugins;
+using AwsWrapperDataProvider.Driver.Utils;
 using AwsWrapperDataProvider.Properties;
+using Microsoft.Extensions.Logging;
 
 namespace AwsWrapperDataProvider.Driver;
 
 public class ConnectionPluginManager
 {
     private readonly Dictionary<string, Delegate> pluginChainDelegates = [];
     protected IList<IConnectionPlugin> plugins = [];
+    protected string[] activePluginCodes = [];
     protected IConnectionProvider defaultConnProvider;
     protected IConnectionProvider? effectiveConnProvider;
     protected ConfigurationProfile? configurationProfile;
@@ -90,6 +93,7 @@ public void InitConnectionPluginChain(
             this.effectiveConnProvider,
             props,
             this.configurationProfile);
+        this.activePluginCodes = pluginChainBuilder.GetPluginCodes(this.pluginService, props);
     }
 
     private async Task<T> ExecuteWithSubscribedPlugins<T>(
@@ -104,7 +108,7 @@ private async Task<T> ExecuteWithSubscribedPlugins<T>(
         if (!this.pluginChainDelegates.TryGetValue(methodName, out Delegate? del))
         {
             del = this.MakePluginChainDelegate<T>(methodName);
-            this.pluginChainDelegates.Add(methodName, del);
+            this.pluginChainDelegates[methodName] = del;
         }
 
         if (del is not PluginChainADONetDelegate<T> pluginChainDelegate)
@@ -130,7 +134,6 @@ private async Task<T> ExecuteWithSubscribedPlugins<T>(
     private PluginChainADONetDelegate<T> MakePluginChainDelegate<T>(string methodName)
     {
         PluginChainADONetDelegate<T>? pluginChainDelegate = null;
-
         for (int i = this.plugins.Count - 1; i >= 0; i--)
         {
             IConnectionPlugin plugin = this.plugins[i];
@@ -248,4 +251,9 @@ public virtual bool AcceptsStrategy(string strategy)
     {
         return this.defaultConnProvider.AcceptsStrategy(strategy);
     }
+
+    public bool IsPluginActive(string pluginCode)
+    {
+        return this.activePluginCodes.Contains(pluginCode);
+    }
 }

AwsWrapperDataProvider/Driver/Dialects/AuroraMySqlDialect.cs

@@ -21,7 +21,7 @@
 
 namespace AwsWrapperDataProvider.Driver.Dialects;
 
-public class AuroraMySqlDialect : MySqlDialect
+public class AuroraMySqlDialect : MySqlDialect, IBlueGreenDialect
 {
     private static readonly ILogger<AuroraMySqlDialect> Logger = LoggerUtils.GetLogger<AuroraMySqlDialect>();
 
@@ -39,6 +39,10 @@ public class AuroraMySqlDialect : MySqlDialect
     private static readonly string IsWriterQuery = "SELECT SERVER_ID FROM information_schema.replica_host_status "
         + "WHERE SESSION_ID = 'MASTER_SESSION_ID' AND SERVER_ID = @@aurora_server_id";
 
+    private static readonly string AuroraMySqlBgTopologyExistsQuery = "SELECT 1 AS tmp FROM information_schema.tables WHERE table_schema = 'mysql' AND table_name = 'rds_topology'";
+
+    private static readonly string AuroraMySqlBgStatusQuery = "SELECT * FROM mysql.rds_topology";
+
     public override IList<Type> DialectUpdateCandidates { get; } = [
         typeof(RdsMultiAzDbClusterMySqlDialect),
     ];
@@ -54,7 +58,7 @@ public override async Task<bool> IsDialect(DbConnection connection)
         }
         catch (Exception ex) when (this.ExceptionHandler.IsSyntaxError(ex))
         {
-            // Syntax error - expected when querying against incorrect dialect
+            Logger.LogTrace(ex, Resources.Error_CantCheckDialect_Syntax, nameof(AuroraMySqlDialect));
         }
         catch (Exception ex)
         {
@@ -85,4 +89,14 @@ private HostListProviderSupplier GetHostListProviderSupplier()
                     NodeIdQuery,
                     IsReaderQuery);
     }
+
+    public async Task<bool> IsBlueGreenStatusAvailable(DbConnection connection)
+    {
+        return await DialectUtils.CheckExistenceQueries(connection, this.ExceptionHandler, Logger, AuroraMySqlBgTopologyExistsQuery);
+    }
+
+    public string GetBlueGreenStatusQuery()
+    {
+        return AuroraMySqlBgStatusQuery;
+    }
 }

AwsWrapperDataProvider/Driver/Dialects/AuroraPgDialect.cs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 using System.Data.Common;
+using System.Reflection;
 using AwsWrapperDataProvider.Driver.HostListProviders;
 using AwsWrapperDataProvider.Driver.HostListProviders.Monitoring;
 using AwsWrapperDataProvider.Driver.Utils;
@@ -21,7 +22,7 @@
 
 namespace AwsWrapperDataProvider.Driver.Dialects;
 
-public class AuroraPgDialect : PgDialect, IAuroraLimitlessDialect
+public class AuroraPgDialect : PgDialect, IAuroraLimitlessDialect, IBlueGreenDialect
 {
     private const string ReaderOrdinal = "aurora_stat_utils";
 
@@ -48,6 +49,11 @@ public class AuroraPgDialect : PgDialect, IAuroraLimitlessDialect
     private static readonly string IsWriterQuery = "SELECT SERVER_ID FROM pg_catalog.aurora_replica_status() "
         + "WHERE SESSION_ID OPERATOR(pg_catalog.=) 'MASTER_SESSION_ID' AND SERVER_ID OPERATOR(pg_catalog.=) aurora_db_instance_identifier()";
 
+    protected static readonly string AuroraPostgreSqlBgTopologyExistsQuery = "SELECT 'pg_catalog.get_blue_green_fast_switchover_metadata'::regproc";
+
+    protected static readonly string DriverVersion = "1.0.1";
+    protected static readonly string AuroraPostgreSqlBgStatusQuery = $"SELECT * FROM pg_catalog.get_blue_green_fast_switchover_metadata('aws_advanced_dotnet_data_provider_wrapper-{DriverVersion}')";
+
     public override IList<Type> DialectUpdateCandidates { get; } = [
         typeof(RdsMultiAzDbClusterPgDialect),
     ];
@@ -115,5 +121,15 @@ private HostListProviderSupplier GetHostListProviderSupplier()
                     IsReaderQuery);
     }
 
+    public async Task<bool> IsBlueGreenStatusAvailable(DbConnection connection)
+    {
+        return await DialectUtils.CheckExistenceQueries(connection, this.ExceptionHandler, Logger, AuroraPostgreSqlBgTopologyExistsQuery);
+    }
+
+    public string GetBlueGreenStatusQuery()
+    {
+        return AuroraPostgreSqlBgStatusQuery;
+    }
+
     public string LimitlessRouterEndpointQuery { get => "SELECT router_endpoint, load from aurora_limitless_router_endpoints()"; }
 }

AwsWrapperDataProvider/Driver/Dialects/DialectUtils.cs

@@ -0,0 +1,49 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License").
+// You may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.Data.Common;
+using AwsWrapperDataProvider.Driver.Exceptions;
+using AwsWrapperDataProvider.Properties;
+using Microsoft.Extensions.Logging;
+
+namespace AwsWrapperDataProvider.Driver.Dialects;
+
+public static class DialectUtils
+{
+    public static async Task<bool> CheckExistenceQueries(DbConnection connection, IExceptionHandler exceptionHandler, ILogger logger, string query)
+    {
+        try
+        {
+            await using var command = connection.CreateCommand();
+            command.CommandText = query;
+            await using var reader = await command.ExecuteReaderAsync();
+            return await reader.ReadAsync();
+        }
+        catch (Exception ex) when (exceptionHandler.IsSyntaxError(ex))
+        {
+            // Syntax error - expected when querying against incorrect dialect
+        }
+        catch (Exception ex)
+        {
+            logger.LogTrace(ex, Resources.Error_CantCheckDialect, nameof(AuroraMySqlDialect));
+        }
+
+        return false;
+    }
+
+    public static bool IsBlueGreenConnectionDialect(IDialect dialect)
+    {
+        return dialect is IBlueGreenDialect;
+    }
+}

AwsWrapperDataProvider/Driver/Dialects/IBlueGreenDialect.cs

@@ -0,0 +1,24 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License").
+// You may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.Data.Common;
+
+namespace AwsWrapperDataProvider.Driver.Dialects;
+
+public interface IBlueGreenDialect
+{
+    Task<bool> IsBlueGreenStatusAvailable(DbConnection connection);
+
+    string GetBlueGreenStatusQuery();
+}

AwsWrapperDataProvider/Driver/Dialects/RdsMultiAzDbClusterPgDialect.cs

@@ -32,7 +32,7 @@ public class RdsMultiAzDbClusterPgDialect : PgDialect
     private static readonly ILogger<RdsMultiAzDbClusterPgDialect> Logger = LoggerUtils.GetLogger<RdsMultiAzDbClusterPgDialect>();
 
     private static readonly string TopologyQuery =
-        $"SELECT id, endpoint, port FROM rds_tools.show_topology('aws_dotnet_driver-{DriverVersion}')";
+        $"SELECT id, endpoint, port FROM rds_tools.show_topology('aws_advanced_dotnet_data_provider_wrapper-{DriverVersion}')";
 
     private static readonly string FetchWriterNodeQuery =
         "SELECT multi_az_db_cluster_source_dbi_resource_id FROM rds_tools.multi_az_db_cluster_source_dbi_resource_id()"

AwsWrapperDataProvider/Driver/Dialects/RdsMySqlDialect.cs

@@ -19,8 +19,13 @@
 
 namespace AwsWrapperDataProvider.Driver.Dialects;
 
-public class RdsMySqlDialect : MySqlDialect
+public class RdsMySqlDialect : MySqlDialect, IBlueGreenDialect
 {
+    protected static readonly string RdsMySqlTopologyTableExistsQuery = "SELECT 1 AS tmp FROM information_schema.tables WHERE" +
+                                                                        " table_schema = 'mysql' AND table_name = 'rds_topology'";
+
+    protected static readonly string RdsMySqlBgStatusQuery = "SELECT * FROM mysql.rds_topology";
+
     private static readonly ILogger<RdsMySqlDialect> Logger = LoggerUtils.GetLogger<RdsMySqlDialect>();
 
     public override IList<Type> DialectUpdateCandidates { get; } =
@@ -56,7 +61,7 @@ public override async Task<bool> IsDialect(DbConnection conn)
         }
         catch (Exception ex) when (this.ExceptionHandler.IsSyntaxError(ex))
         {
-            // Syntax error - expected when querying against incorrect dialect
+            Logger.LogTrace(ex, Resources.Error_CantCheckDialect_Syntax, nameof(RdsPgDialect));
         }
         catch (Exception ex)
         {
@@ -65,4 +70,14 @@ public override async Task<bool> IsDialect(DbConnection conn)
 
         return false;
     }
+
+    public async Task<bool> IsBlueGreenStatusAvailable(DbConnection connection)
+    {
+        return await DialectUtils.CheckExistenceQueries(connection, this.ExceptionHandler, Logger, RdsMySqlTopologyTableExistsQuery);
+    }
+
+    public string GetBlueGreenStatusQuery()
+    {
+        return RdsMySqlBgStatusQuery;
+    }
 }

AwsWrapperDataProvider/Driver/Dialects/RdsPgDialect.cs

@@ -19,13 +19,17 @@
 
 namespace AwsWrapperDataProvider.Driver.Dialects;
 
-public class RdsPgDialect : PgDialect
+public class RdsPgDialect : PgDialect, IBlueGreenDialect
 {
     internal const string ExtensionsSql = "SELECT (setting LIKE '%rds_tools%') AS rds_tools, "
                                          + "(setting LIKE '%aurora_stat_utils%') AS aurora_stat_utils "
                                          + "FROM pg_catalog.pg_settings "
                                          + "WHERE name OPERATOR(pg_catalog.=) 'rds.extensions'";
 
+    protected static readonly string RdsPgTopologyTableExistsQuery = "SELECT 'rds_tools.show_topology'::regproc";
+
+    protected static readonly string RdsPgBgStatusQuery = "SELECT * FROM rds_tools.show_topology('aws_advanced_dotnet_data_provider_wrapper')";
+
     private static readonly ILogger<RdsPgDialect> Logger = LoggerUtils.GetLogger<RdsPgDialect>();
 
     public override IList<Type> DialectUpdateCandidates { get; } =
@@ -58,7 +62,7 @@ public override async Task<bool> IsDialect(DbConnection conn)
         }
         catch (Exception ex) when (this.ExceptionHandler.IsSyntaxError(ex))
         {
-            // Syntax error - expected when querying against incorrect dialect
+            Logger.LogTrace(ex, Resources.Error_CantCheckDialect_Syntax, nameof(RdsPgDialect));
         }
         catch (Exception ex)
         {
@@ -67,4 +71,14 @@ public override async Task<bool> IsDialect(DbConnection conn)
 
         return false;
     }
+
+    public async Task<bool> IsBlueGreenStatusAvailable(DbConnection connection)
+    {
+        return await DialectUtils.CheckExistenceQueries(connection, this.ExceptionHandler, Logger, RdsPgTopologyTableExistsQuery);
+    }
+
+    public string GetBlueGreenStatusQuery()
+    {
+        return RdsPgBgStatusQuery;
+    }
 }

AwsWrapperDataProvider/Driver/HostInfo/HostSpec.cs

@@ -195,4 +195,11 @@ public override string ToString()
             this.LastUpdateTime,
             this.HostId);
     }
+
+    public HostSpec Clone()
+    {
+        HostSpec copy = new(this.Host, this.Port, this.HostId, this.Role, this.RawAvailability, this.Weight, this.LastUpdateTime);
+        copy.AddAlias(this.aliases.Keys.ToArray());
+        return copy;
+    }
 }

AwsWrapperDataProvider/Driver/IPluginService.cs

@@ -182,4 +182,11 @@ public interface IPluginService : IExceptionHandlerService
     HostSpec GetHostSpecByStrategy(HostRole hostRole, string strategy);
 
     HostSpec GetHostSpecByStrategy(IList<HostSpec> hosts, HostRole hostRole, string strategy);
+
+    /// <summary>
+    /// Checks if a specific plugin type is currently in use.
+    /// </summary>
+    /// <param name="pluginCode">The name of the plugin.</param>
+    /// <returns>True if the plugin is in use, false otherwise.</returns>
+    bool IsPluginInUse(string pluginCode);
 }

AwsWrapperDataProvider/Driver/PluginService.cs

@@ -430,6 +430,11 @@ public HostSpec GetHostSpecByStrategy(IList<HostSpec> hosts, HostRole hostRole,
         return this.pluginManager.GetHostSpecByStrategy(hosts, hostRole, strategy, this.props);
     }
 
+    public bool IsPluginInUse(string pluginCode)
+    {
+        return this.pluginManager.IsPluginActive(pluginCode);
+    }
+
     private HostSpec GetCurrentHostSpec()
     {
         this.currentHostSpec = this.InitialConnectionHostSpec