Description:
I am currently using net8.0 (though I have also tested this on net6.0), along with the latest versions of EntityFrameworkCore and MySql.EntityFrameworkCore and MySQL 8.0.35 (both on docker and installed on host machine). My connection string includes "Min Pool Size=10". The application runs smoothly on various windows platforms: Windows machine, an Ubuntu VM on Windows, a Docker Compose on a Windows machine, and even on Azure. However, when I attempt to run the same application on Ubuntu 22.04 machine, or a Docker Compose on an Ubuntu 22.04 machine, it hangs while trying to establish a connection to the database
When I remove the "Min Pool Size=10" from the connection string, the application runs without any issues in all tested environments. Despite increasing the timeout in the connection string, the application continues to stall if "Min Pool Size > 0" is present.
This is the exception:
app | Unhandled exception. System.AggregateException: One or more errors occurred. (Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.)
app | ---> MySql.Data.MySqlClient.MySqlException (0x80004005): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
app | ---> System.TimeoutException: The operation has timed out.
app | at MySql.Data.Common.StreamCreator.<>c.<GetTcpStreamAsync>b__8_1()
app | at System.Threading.CancellationTokenSource.Invoke(Delegate d, Object state, CancellationTokenSource source)
app | at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
app | --- End of stack trace from previous location ---
app | at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
app | at System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(Boolean throwOnFirstException)
app | --- End of inner exception stack trace ---
app | at System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(Boolean throwOnFirstException)
app | at System.Threading.TimerQueueTimer.Fire(Boolean isThreadPool)
app | at System.Threading.TimerQueue.FireNextTimers()
app | at System.Threading.ThreadPoolWorkQueue.Dispatch()
app | at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()
How to repeat:
My original application is an ASPNET Core API, but I was able to replicate the issue using a simple console application:
TestApp:
static async Task Main(string[] args)
{
var envCnx = Environment.GetEnvironmentVariable("CONNECTION_STRING");
IDbContextFactory dbContextFactory = new AppDbContextFactory(envCnx);
using var db = await dbContextFactory.CreateDbContextAsync();
await db.Database.MigrateAsync();
var name = "User 1";
if (!await db.Set<UserInfo>().AnyAsync(x => x.Name == name))
{
db.Add(new UserInfo() { Id = Guid.NewGuid(), Name = name, CreatedOn = DateTime.Now });
await db.SaveChangesAsync();
}
}
AppDbContextFactory:
public interface IDbContextFactory : IDbContextFactory<DbContext>
{
}
public class AppDbContextFactory : IDesignTimeDbContextFactory<AppDbContext>, IDbContextFactory<AppDbContext>, IDbContextFactory
{
private readonly string _cnx;
public AppDbContextFactory(string cnx)
{
_cnx = cnx;
}
public AppDbContext CreateDbContext(string[] args)
{
var optionsBuilder = new DbContextOptionsBuilder<AppDbContext>();
string cnx = args.Length > 0 ? args[0] : this._cnx;
#if DEBUG
optionsBuilder.EnableSensitiveDataLogging();
optionsBuilder.EnableDetailedErrors();
#endif
optionsBuilder.UseMySql(cnx, ServerVersion.AutoDetect(cnx), mySqlOpts =>
{
mySqlOpts.UseNewtonsoftJson();
mySqlOpts.MigrationsAssembly(typeof(AppDbContext).Assembly.FullName);
})
#if DEBUG
.EnableSensitiveDataLogging()
.EnableDetailedErrors()
#endif
;
return new AppDbContext(optionsBuilder.Options);
}
public AppDbContext GetContext()
{
return CreateDbContext([_cnx]);
}
public AppDbContext CreateDbContext()
{
return GetContext();
}
DbContext IDbContextFactory<DbContext>.CreateDbContext()
{
return GetContext();
}
}
AppDbContext:
public class AppDbContext : DbContext
{
public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<UserInfo>().HasKey(x => x.Id);
modelBuilder.Entity<UserInfo>().HasIndex(x => x.Id).IsUnique();
modelBuilder.Entity<UserInfo>().Property(t => t.Id).ValueGeneratedOnAdd();
modelBuilder.Entity<UserInfo>().Property(x => x.Timestamp).IsRowVersion();
modelBuilder.Entity<UserInfo>().HasIndex(x => x.Name);
modelBuilder.Entity<UserInfo>().ToTable("users");
}
}
UserInfo:
public class UserInfo
{
[JsonConstructor]
public UserInfo() { }
public Guid Id { get; set; }
public string Name { get; set; }
public DateTimeOffset CreatedOn { get; set; }
public DateTime Timestamp { get; set; }
}
Dockerfile:
#See https://aka.ms/customizecontainer to learn how to customize your debug container and how Visual Studio uses this Dockerfile to build your images for faster debugging.
FROM mcr.microsoft.com/dotnet/runtime:8.0 AS base
USER app
WORKDIR /app
FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
ARG BUILD_CONFIGURATION=Release
WORKDIR /src
COPY ["ConsoleTestApp/ConsoleTestApp.csproj", "ConsoleTestApp/"]
RUN dotnet restore "./ConsoleTestApp/ConsoleTestApp.csproj"
COPY . .
WORKDIR "/src/ConsoleTestApp"
RUN dotnet build "./ConsoleTestApp.csproj" -c $BUILD_CONFIGURATION -o /app/build
FROM build AS publish
ARG BUILD_CONFIGURATION=Release
RUN dotnet publish "./ConsoleTestApp.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false
FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "ConsoleTestApp.dll"]
docker-compose.yml
version: "3.3"
name: "test-app"
services:
app:
image: console-app:latest
container_name: console-app
depends_on:
- mysql
environment:
# CONNECTION_STRING: server=mysql,3306;user=root;password=2YSCK+fktPRGOi5omfRjCAP_am9+3r;database=test_db
CONNECTION_STRING: server=mysql,3306;user=root;password=2YSCK+fktPRGOi5omfRjCAP_am9+3r;database=test_db;Min Pool Size=10;Connect Timeout=600
mysql:
container_name: db
image: mysql:8.0.35
cap_add:
- SYS_NICE
restart: always
ports:
- "3306:3306"
environment:
MYSQL_ROOT_PASSWORD: 2YSCK+fktPRGOi5omfRjCAP_am9+3r
MYSQL_DATABASE: test_db
project structure:
.
├── ConsoleTestApp
│ ├── ConsoleTestApp.csproj
│ ├── Data
│ │ ├── AppDbContext.cs
│ │ ├── AppDbContextFactory.cs
│ │ ├── Migrations
│ │ │ ├── 20240523164903_InitialMigration.Designer.cs
│ │ │ ├── 20240523164903_InitialMigration.cs
│ │ │ └── AppDbContextModelSnapshot.cs
│ │ └── UserInfo.cs
│ ├── Program.cs
│ └── Properties
│ └── launchSettings.json
├── ConsoleTestApp.sln
├── Dockerfile
└── docker-compose.yml
Description: I am currently using net8.0 (though I have also tested this on net6.0), along with the latest versions of EntityFrameworkCore and MySql.EntityFrameworkCore and MySQL 8.0.35 (both on docker and installed on host machine). My connection string includes "Min Pool Size=10". The application runs smoothly on various windows platforms: Windows machine, an Ubuntu VM on Windows, a Docker Compose on a Windows machine, and even on Azure. However, when I attempt to run the same application on Ubuntu 22.04 machine, or a Docker Compose on an Ubuntu 22.04 machine, it hangs while trying to establish a connection to the database When I remove the "Min Pool Size=10" from the connection string, the application runs without any issues in all tested environments. Despite increasing the timeout in the connection string, the application continues to stall if "Min Pool Size > 0" is present. This is the exception: app | Unhandled exception. System.AggregateException: One or more errors occurred. (Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.) app | ---> MySql.Data.MySqlClient.MySqlException (0x80004005): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. app | ---> System.TimeoutException: The operation has timed out. app | at MySql.Data.Common.StreamCreator.<>c.<GetTcpStreamAsync>b__8_1() app | at System.Threading.CancellationTokenSource.Invoke(Delegate d, Object state, CancellationTokenSource source) app | at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) app | --- End of stack trace from previous location --- app | at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) app | at System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(Boolean throwOnFirstException) app | --- End of inner exception stack trace --- app | at System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(Boolean throwOnFirstException) app | at System.Threading.TimerQueueTimer.Fire(Boolean isThreadPool) app | at System.Threading.TimerQueue.FireNextTimers() app | at System.Threading.ThreadPoolWorkQueue.Dispatch() app | at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart() How to repeat: My original application is an ASPNET Core API, but I was able to replicate the issue using a simple console application: TestApp: static async Task Main(string[] args) { var envCnx = Environment.GetEnvironmentVariable("CONNECTION_STRING"); IDbContextFactory dbContextFactory = new AppDbContextFactory(envCnx); using var db = await dbContextFactory.CreateDbContextAsync(); await db.Database.MigrateAsync(); var name = "User 1"; if (!await db.Set<UserInfo>().AnyAsync(x => x.Name == name)) { db.Add(new UserInfo() { Id = Guid.NewGuid(), Name = name, CreatedOn = DateTime.Now }); await db.SaveChangesAsync(); } } AppDbContextFactory: public interface IDbContextFactory : IDbContextFactory<DbContext> { } public class AppDbContextFactory : IDesignTimeDbContextFactory<AppDbContext>, IDbContextFactory<AppDbContext>, IDbContextFactory { private readonly string _cnx; public AppDbContextFactory(string cnx) { _cnx = cnx; } public AppDbContext CreateDbContext(string[] args) { var optionsBuilder = new DbContextOptionsBuilder<AppDbContext>(); string cnx = args.Length > 0 ? args[0] : this._cnx; #if DEBUG optionsBuilder.EnableSensitiveDataLogging(); optionsBuilder.EnableDetailedErrors(); #endif optionsBuilder.UseMySql(cnx, ServerVersion.AutoDetect(cnx), mySqlOpts => { mySqlOpts.UseNewtonsoftJson(); mySqlOpts.MigrationsAssembly(typeof(AppDbContext).Assembly.FullName); }) #if DEBUG .EnableSensitiveDataLogging() .EnableDetailedErrors() #endif ; return new AppDbContext(optionsBuilder.Options); } public AppDbContext GetContext() { return CreateDbContext([_cnx]); } public AppDbContext CreateDbContext() { return GetContext(); } DbContext IDbContextFactory<DbContext>.CreateDbContext() { return GetContext(); } } AppDbContext: public class AppDbContext : DbContext { public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) { } protected override void OnModelCreating(ModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder); modelBuilder.Entity<UserInfo>().HasKey(x => x.Id); modelBuilder.Entity<UserInfo>().HasIndex(x => x.Id).IsUnique(); modelBuilder.Entity<UserInfo>().Property(t => t.Id).ValueGeneratedOnAdd(); modelBuilder.Entity<UserInfo>().Property(x => x.Timestamp).IsRowVersion(); modelBuilder.Entity<UserInfo>().HasIndex(x => x.Name); modelBuilder.Entity<UserInfo>().ToTable("users"); } } UserInfo: public class UserInfo { [JsonConstructor] public UserInfo() { } public Guid Id { get; set; } public string Name { get; set; } public DateTimeOffset CreatedOn { get; set; } public DateTime Timestamp { get; set; } } Dockerfile: #See https://aka.ms/customizecontainer to learn how to customize your debug container and how Visual Studio uses this Dockerfile to build your images for faster debugging. FROM mcr.microsoft.com/dotnet/runtime:8.0 AS base USER app WORKDIR /app FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build ARG BUILD_CONFIGURATION=Release WORKDIR /src COPY ["ConsoleTestApp/ConsoleTestApp.csproj", "ConsoleTestApp/"] RUN dotnet restore "./ConsoleTestApp/ConsoleTestApp.csproj" COPY . . WORKDIR "/src/ConsoleTestApp" RUN dotnet build "./ConsoleTestApp.csproj" -c $BUILD_CONFIGURATION -o /app/build FROM build AS publish ARG BUILD_CONFIGURATION=Release RUN dotnet publish "./ConsoleTestApp.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false FROM base AS final WORKDIR /app COPY --from=publish /app/publish . ENTRYPOINT ["dotnet", "ConsoleTestApp.dll"] docker-compose.yml version: "3.3" name: "test-app" services: app: image: console-app:latest container_name: console-app depends_on: - mysql environment: # CONNECTION_STRING: server=mysql,3306;user=root;password=2YSCK+fktPRGOi5omfRjCAP_am9+3r;database=test_db CONNECTION_STRING: server=mysql,3306;user=root;password=2YSCK+fktPRGOi5omfRjCAP_am9+3r;database=test_db;Min Pool Size=10;Connect Timeout=600 mysql: container_name: db image: mysql:8.0.35 cap_add: - SYS_NICE restart: always ports: - "3306:3306" environment: MYSQL_ROOT_PASSWORD: 2YSCK+fktPRGOi5omfRjCAP_am9+3r MYSQL_DATABASE: test_db project structure: . ├── ConsoleTestApp │ ├── ConsoleTestApp.csproj │ ├── Data │ │ ├── AppDbContext.cs │ │ ├── AppDbContextFactory.cs │ │ ├── Migrations │ │ │ ├── 20240523164903_InitialMigration.Designer.cs │ │ │ ├── 20240523164903_InitialMigration.cs │ │ │ └── AppDbContextModelSnapshot.cs │ │ └── UserInfo.cs │ ├── Program.cs │ └── Properties │ └── launchSettings.json ├── ConsoleTestApp.sln ├── Dockerfile └── docker-compose.yml