Skip to content

configurable-retry-logic-core-apis-sqlclient.md

Latest commit

 

History

History
73 lines (45 loc) · 4.64 KB

configurable-retry-logic-core-apis-sqlclient.md

File metadata and controls

73 lines (45 loc) · 4.64 KB
title Configurable retry logic core APIs in SqlClient
description Learn how to use the configurable retry logic core APIs to implement custom retry logic in your application with Microsoft.Data.SqlClient.
author David-Engel
ms.author davidengel
ms.reviewer v-deshtehari
ms.date 03/22/2021
ms.service sql
ms.subservice connectivity
ms.topic how-to

Configurable retry logic core APIs in SqlClient

[!INCLUDE dotnet-all]

[!INCLUDEDriver_ADONET_Download]

If the built-in retry logic providers don't cover your needs, you can create your own custom providers. You can then assign those providers to a SqlConnection or SqlCommand object to apply your custom logic.

The built-in providers are designed around three interfaces that can be used to implement custom providers. Custom retry providers can then be used in the same way as internal retry providers on a xref:Microsoft.Data.SqlClient.SqlConnection or xref:Microsoft.Data.SqlClient.SqlCommand:

  1. xref:Microsoft.Data.SqlClient.SqlRetryIntervalBaseEnumerator: Generates a sequence of time intervals.
  2. xref:Microsoft.Data.SqlClient.SqlRetryLogicBase: Retrieves the next time interval for a given enumerator, if the number of retries has not been exceeded and a transient condition is met.
  3. xref:Microsoft.Data.SqlClient.SqlRetryLogicBaseProvider: Applies retry logic to connection and command operations.

Caution

By implementing a custom retry logic provider, you're in charge of all aspects, including concurrency, performance, and exception management.

Example

The implementation in this sample is as simple as possible to demonstrate step-by-step customization. It doesn't include advanced practices like thread safety, async, and concurrency. For a deep-dive into a real implementation, you can study the pre-defined retry logic in the Microsoft.Data.SqlClient GitHub repository.

  1. Define custom configurable retry logic classes:

    • Enumerator: Define a fixed sequence of time intervals and extend the acceptable range of times from two minutes to four minutes.

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#6]

    • Retry logic: Implement retry logic on any command that isn't part of an active transaction. Lower the number of retries from 60 to 20.

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#7]

    • Provider: Implements a retry provider that retries on synchronous operations without a Retrying event. Adds xref:System.TimeoutException to the existing xref:Microsoft.Data.SqlClient.SqlException transient exception error numbers.

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#8]

  2. Create a retry provider instance consisting of the defined custom types:

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#4]

    • The following function will evaluate an exception by using the given list of retryable exceptions and the special xref:System.TimeoutException exception to determine if it's retryable:

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#5]

  3. Use the customized retry logic:

    • Define the retry logic parameters:

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#1]

    • Create a custom retry provider:

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#2]

    • Assign the retry provider to the xref:Microsoft.Data.SqlClient.SqlConnection.RetryLogicProvider%2A?displayProperty=nameWithType or xref:Microsoft.Data.SqlClient.SqlCommand.RetryLogicProvider%2A?displayProperty=nameWithType:

    [!code-csharpSqlConfigurableRetryLogic_StepByStep_CustomProvider#3]

See also