Use reserved UOW also for the UOW interceptor. Also, allow web layer to determine transaction behaviour.

framework/src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/Uow/AbpUowActionFilter.cs

@@ -46,7 +46,7 @@ namespace Volo.Abp.AspNetCore.Mvc.Uow
             var options = CreateOptions(context, unitOfWorkAttr);
 
             //Trying to begin a reserved UOW by AbpUnitOfWorkMiddleware
-            if (_unitOfWorkManager.TryBeginReserved(AbpUnitOfWorkMiddleware.UnitOfWorkReservationName, options))
+            if (_unitOfWorkManager.TryBeginReserved(UnitOfWork.UnitOfWorkReservationName, options))
             {
                 var result = await next();
                 if (!Succeed(result))

framework/src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/Uow/AbpUowPageFilter.cs

@@ -50,7 +50,7 @@ namespace Volo.Abp.AspNetCore.Mvc.Uow
             var options = CreateOptions(context, unitOfWorkAttr);
 
             //Trying to begin a reserved UOW by AbpUnitOfWorkMiddleware
-            if (_unitOfWorkManager.TryBeginReserved(AbpUnitOfWorkMiddleware.UnitOfWorkReservationName, options))
+            if (_unitOfWorkManager.TryBeginReserved(UnitOfWork.UnitOfWorkReservationName, options))
             {
                 var result = await next();
                 if (!Succeed(result))

framework/src/Volo.Abp.AspNetCore/Volo/Abp/AspNetCore/Uow/AbpUnitOfWorkMiddleware.cs

@@ -7,8 +7,6 @@ namespace Volo.Abp.AspNetCore.Uow
 {
     public class AbpUnitOfWorkMiddleware : IMiddleware, ITransientDependency
     {
-        public const string UnitOfWorkReservationName = "_AbpActionUnitOfWork";
-
         private readonly IUnitOfWorkManager _unitOfWorkManager;
 
         public AbpUnitOfWorkMiddleware(IUnitOfWorkManager unitOfWorkManager)
@@ -18,7 +16,7 @@ namespace Volo.Abp.AspNetCore.Uow
 
         public async Task InvokeAsync(HttpContext context, RequestDelegate next)
         {
-            using (var uow = _unitOfWorkManager.Reserve(UnitOfWorkReservationName))
+            using (var uow = _unitOfWorkManager.Reserve(UnitOfWork.UnitOfWorkReservationName))
             {
                 await next(context);
                 await uow.CompleteAsync(context.RequestAborted);

framework/src/Volo.Abp.AspNetCore/Volo/Abp/AspNetCore/Uow/AspNetCoreUnitOfWorkTransactionBehaviourProvider.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Net.Http;
+using Microsoft.AspNetCore.Http;
+using Volo.Abp.DependencyInjection;
+using Volo.Abp.Uow;
+
+namespace Volo.Abp.AspNetCore.Uow
+{
+    public class AspNetCoreUnitOfWorkTransactionBehaviourProvider : IUnitOfWorkTransactionBehaviourProvider, ITransientDependency
+    {
+        private readonly IHttpContextAccessor _httpContextAccessor;
+
+        public virtual bool? IsTransactional
+        {
+            get
+            {
+                var httpContext = _httpContextAccessor.HttpContext;
+                if (httpContext == null)
+                {
+                    return null;
+                }
+
+                //IdentityServer endpoint (TODO: Better to move to the IDS module)
+                if (httpContext.Request.Path.Value?.StartsWith("/connect/", StringComparison.OrdinalIgnoreCase) == true)
+                {
+                    return false;
+                }
+
+                return !string.Equals(
+                    httpContext.Request.Method,
+                    HttpMethod.Get.Method, StringComparison.OrdinalIgnoreCase
+                );
+            }
+        }
+
+        public AspNetCoreUnitOfWorkTransactionBehaviourProvider(IHttpContextAccessor httpContextAccessor)
+        {
+            _httpContextAccessor = httpContextAccessor;
+        }
+    }
+}

framework/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/UnitOfWorkDbContextProvider.cs

@@ -133,6 +133,8 @@ namespace Volo.Abp.Uow.EntityFrameworkCore
 
         private async Task<TDbContext> CreateDbContextAsync(IUnitOfWork unitOfWork)
         {
+            Logger.LogDebug($"Creating a new DbContext of type {typeof(TDbContext).FullName}");
+
             return unitOfWork.Options.IsTransactional
                 ? await CreateDbContextWithTransactionAsync(unitOfWork)
                 : unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/IUnitOfWorkTransactionBehaviourProvider.cs

@@ -0,0 +1,7 @@
+namespace Volo.Abp.Uow
+{
+    public interface IUnitOfWorkTransactionBehaviourProvider
+    {
+        bool? IsTransactional { get; }
+    }
+}

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/NullUnitOfWorkTransactionBehaviourProvider.cs

@@ -0,0 +1,9 @@
+using Volo.Abp.DependencyInjection;
+
+namespace Volo.Abp.Uow
+{
+    public class NullUnitOfWorkTransactionBehaviourProvider : IUnitOfWorkTransactionBehaviourProvider, ISingletonDependency
+    {
+        public bool? IsTransactional => null;
+    }
+}

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/UnitOfWork.cs

@@ -11,6 +11,8 @@ namespace Volo.Abp.Uow
 {
     public class UnitOfWork : IUnitOfWork, ITransientDependency
     {
+        public const string UnitOfWorkReservationName = "_AbpActionUnitOfWork";
+
         public Guid Id { get; } = Guid.NewGuid();
 
         public IAbpUnitOfWorkOptions Options { get; private set; }
@@ -302,7 +304,7 @@ namespace Volo.Abp.Uow
                 }
             }
         }
-        
+
         protected virtual async Task CommitTransactionsAsync()
         {
             foreach (var transaction in GetAllActiveTransactionApis())

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/UnitOfWorkInterceptor.cs

@@ -10,11 +10,16 @@ namespace Volo.Abp.Uow
     public class UnitOfWorkInterceptor : AbpInterceptor, ITransientDependency
     {
         private readonly IUnitOfWorkManager _unitOfWorkManager;
+        private readonly IUnitOfWorkTransactionBehaviourProvider _transactionBehaviourProvider;
         private readonly AbpUnitOfWorkDefaultOptions _defaultOptions;
 
-        public UnitOfWorkInterceptor(IUnitOfWorkManager unitOfWorkManager, IOptions<AbpUnitOfWorkDefaultOptions> options)
+        public UnitOfWorkInterceptor(
+            IUnitOfWorkManager unitOfWorkManager,
+            IOptions<AbpUnitOfWorkDefaultOptions> options,
+            IUnitOfWorkTransactionBehaviourProvider transactionBehaviourProvider)
         {
             _unitOfWorkManager = unitOfWorkManager;
+            _transactionBehaviourProvider = transactionBehaviourProvider;
             _defaultOptions = options.Value;
         }
 
@@ -26,7 +31,16 @@ namespace Volo.Abp.Uow
                 return;
             }
 
-            using (var uow = _unitOfWorkManager.Begin(CreateOptions(invocation, unitOfWorkAttribute)))
+            var options = CreateOptions(invocation, unitOfWorkAttribute);
+
+            //Trying to begin a reserved UOW by AbpUnitOfWorkMiddleware
+            if (_unitOfWorkManager.TryBeginReserved(UnitOfWork.UnitOfWorkReservationName, options))
+            {
+                await invocation.ProceedAsync();
+                return;
+            }
+
+            using (var uow = _unitOfWorkManager.Begin(options))
             {
                 await invocation.ProceedAsync();
                 await uow.CompleteAsync();
@@ -42,7 +56,8 @@ namespace Volo.Abp.Uow
             if (unitOfWorkAttribute?.IsTransactional == null)
             {
                 options.IsTransactional = _defaultOptions.CalculateIsTransactional(
-                    autoValue: !invocation.Method.Name.StartsWith("Get", StringComparison.InvariantCultureIgnoreCase)
+                    autoValue: _transactionBehaviourProvider.IsTransactional
+                               ?? !invocation.Method.Name.StartsWith("Get", StringComparison.InvariantCultureIgnoreCase)
                 );
             }