MediatR pipeline for retrying Db deadlocks

DbDeadlockRetryHandlerProcessor.cs

using System;
using System.Data.Common;
using System.Threading;
using System.Threading.Tasks;
using MediatR;

namespace Foo
{
    public class DbDeadlockRetryHandlerProcessor<TRequest, TResponse> : IPipelineBehavior<TRequest, TResponse>
    {
        public async Task<TResponse> Handle(TRequest request, RequestHandlerDelegate<TResponse> next)
        {
            // Retry a deadlock 5 times
            return await HandleWithCountDown(next, 5);
        }

        private async Task<TResponse> HandleWithCountDown(RequestHandlerDelegate<TResponse> next, int count)
        {
            TResponse response;
            try
            {
                response = await next();
            }
            catch (Exception ex)
            {
                // Only catch deadlock exceptions
                if (count <= 0 || !IsDeadlockException(ex))
                {
                    throw;
                }

                await Task.Delay(300);

                response = await HandleWithCountDown(next, count - 1);
            }

            return response;
        }

        private static bool IsDeadlockException(Exception ex)
        {
            while (ex != null)
            {
                if (ex is DbException && ex.Message.Contains("deadlock"))
                {
                    return true;
                }

                ex = ex.InnerException;
            }

            return false;
        }
    }
}