More than twenty 'IServiceProvider' instances have been created for internal use by Entity Framework

[magoogli]

Hi @roji,

As discussed here dotnet/efcore#34918, I am still having issues with the above error when using Npgsql.EntityFrameworkCore.PostgreSQL version 9. I have attempted to create a minimum unit test which reproduces the issue.

https://github.com/magoogli/test-ef-core-multi-tenant-setup

Thank you so much for your time and being willing to have a look at this!

[roji]

Thanks for the repro - there's indeed a bug where different service providers are being created if the data source's connection string differs. I'll fix this for the next patch version.

Minimal repro

for (var i = 0; i < 21; i++)
{
    var dataSource = NpgsqlDataSource.Create($"Host=localhost;Database={i};Include Error Detail=true;Username=admin;Password=admin");
    await using var context = new BlogContext(dataSource);
    _ = context.Model;
}

public class BlogContext(NpgsqlDataSource dataSource) : DbContext
{
    public DbSet<Blog> Blogs { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder.UseNpgsql(dataSource);
}

public class Blog
{
    public int Id { get; set; }
}

[roji]

Backported to 9.0.5 via 6b93c10

@magoogli if you'd like to get this fix before 9.0.5 gets released, you can use version 9.0.5-ci.20250315T090334 or newer from the Npgsql patch feed - this contains only very stable builds that represent the next patch version.

[magoogli]

Thank you so much @roji - I really appreciate that you took the time to investigate and fix this so quickly!