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Curiosus.DAL.EF.Polly

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A prebuilt Polly (v7 API) policy builder that handles Entity Framework Core update errors, for retrying optimistic-concurrency conflicts and failed updates.

Installation​

dotnet add package Curiosus.DAL.EF.Polly

Usage​

PolicyExtensions.GetHandleDbConcurrencyExceptionsPolicy() returns a PolicyBuilder that handles DbUpdateConcurrencyException, DbUpdateException and InvalidOperationException whose inner exception is one of them. Add the retry strategy you need:

using Curiosus.DAL.EF.Polly;
using Microsoft.EntityFrameworkCore;
using Polly;

var retryPolicy = PolicyExtensions.GetHandleDbConcurrencyExceptionsPolicy()
    .WaitAndRetryAsync(3, attempt => TimeSpan.FromMilliseconds(100 * attempt));

await retryPolicy.ExecuteAsync(async ct =>
{
    // use a new context per attempt so that stale tracked entities are not reused
    await using var context = new ShopDataContext(options);
    var order = await context.Orders.SingleAsync(x => x.Id == orderId, ct);
    order.Status = OrderStatus.Paid;
    await context.SaveChangesAsync(ct);
}, cancellationToken);

See also​