Unable to connect to Aurora MySql using .net core application deployed on Aws Ecs

Question

I have an application in .net core 3.1 and I am using MySql with that. To connect to MySql I am using Pomelo.EntityFrameworkCore.MySql nuget.

My .net core application is deployed as a docker container on AWS ECS and I am using Aurora MySql RDS to store data. I have granted "Publicly accessible" access to the Aurora MySql and I can connect to the db using MySql workbench and also with my .net core application using localhost. But when I deploy the application and try to perform any db action then it starts giving throwing exception:

An exception has been raised that is likely due to a transient failure. Consider enabling transient error resiliency by adding 'EnableRetryOnFailure()' to the 'UseMySql' call.

Then I have added retry pattern like this:

 services.AddDbContextPool<DataContext>(options =>
      options.UseMySql(Configuration.GetConnectionString("DefaultConnection"), builder =>
      {
          builder.EnableRetryOnFailure(5, TimeSpan.FromSeconds(5), null);
      }
  );

and my connection string is something like this:

"DefaultConnection": "Server=db-cluster-1-instance-1.cqb2fsjwx78p.us-east-2.rds.amazonaws.com;Database=dbName;User ID=admin;Password=password;port=3306"

After adding retry pattern. I am getting this error:

"Maximum number of retries (5) exceeded while executing database operations with 'MySqlRetryingExecutionStrategy'. See inner exception for the most recent failure."

So I suspect, it's something else. What am I doing wrong here? Or it might be something wrong at aws side

Answer 1

So the issue was related to docker image I was pulling. I was using mcr.microsoft.com/dotnet/core/sdk:3.1. Changing it to mcr.microsoft.com/dotnet/core/sdk:3.1-bionic worked. https://github.com/dotnet/SqlClient/issues/222