是否有任何 ASP.NET 包/DLL 允许 MySQL 查询执行在失败时重试?
我读过Transient Fault Handling 甚至遇到了Dapper issue which shows an example但根据我的研究,这只适用于 SqlServer 和/或 Azure。
我的技术堆栈如下:
- .NET 4.5.2
- Dapper 1.50.2.0
- MySQL 5.6(使用 Amazon Aurora)
最终我试图解决一个sporadic failure issue我相信实现一些重试逻辑将有助于缓解该问题。
我尝试实现此 Dapper issue 中的一些代码但因为我正在使用MySql.Data要连接到我的 MySql 数据库,它无法使用特定于 SqlServer 连接的各种方法。
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using Dapper;
using Microsoft.Practices.EnterpriseLibrary.TransientFaultHandling;
namespace TransientDapper
{
public static class TransientDapperExtensions
{
private static readonly RetryManager SqlRetryManager = GetDefaultRetryManager();
private static readonly RetryPolicy SqlCommandRetryPolicy = SqlRetryManager.GetDefaultSqlCommandRetryPolicy();
private static readonly RetryPolicy SqlConnectionRetryPolicy =
SqlRetryManager.GetDefaultSqlConnectionRetryPolicy();
private static RetryManager GetDefaultRetryManager()
{
const int retryCount = 4;
const int minBackoffDelayMilliseconds = 2000;
const int maxBackoffDelayMilliseconds = 8000;
const int deltaBackoffMilliseconds = 2000;
var exponentialBackoffStrategy =
new ExponentialBackoff(
"exponentialBackoffStrategy",
retryCount,
TimeSpan.FromMilliseconds(minBackoffDelayMilliseconds),
TimeSpan.FromMilliseconds(maxBackoffDelayMilliseconds),
TimeSpan.FromMilliseconds(deltaBackoffMilliseconds)
);
var manager = new RetryManager(
new List<RetryStrategy>
{
exponentialBackoffStrategy
},
exponentialBackoffStrategy.Name
);
return manager;
}
public static void OpenWithRetry(this SqlConnection cnn)
{
cnn.OpenWithRetry(SqlConnectionRetryPolicy);
}
public static IEnumerable<T> QueryWithRetry<T>(
this SqlConnection cnn, string sql, object param = null, IDbTransaction transaction = null,
bool buffered = true, int? commandTimeout = null, CommandType? commandType = null
)
{
return SqlCommandRetryPolicy.ExecuteAction(
() => cnn.Query<T>(sql, param, transaction, buffered, commandTimeout, commandType)
);
}
}
}
最佳答案
发布此内容后不久,我发现了一个名为 Polly 的包这似乎解决了这个“重试”问题。我通过这个StackOverflow question找到了它.
这是我从 MySQL 数据库查询并在失败时重试的实现:
var policy = Policy
.Handle<AuthenticationException>(ex => ex.InnerException is Win32Exception)
.Or<AuthenticationException>()
.Retry((exception, attempt) =>
{
Log.Error(exception, "Class: {Class} | Method: {Method} | Failure executing query, on attempt number: {Attempt}", GetType().Name,
MethodBase.GetCurrentMethod().Name, attempt);
});
try
{
var token = new Token();
policy.Execute(() =>
{
using (var connection = _mySqlDatabase.GetConnection())
{
token = connection.Query<Token>("SELECT * FROM Token...").FirstOrDefault();
}
});
return token;
}
catch (Exception ex)
{
Log.Error(ex, "Class: {Class} | Method: {Method} | Ultimately failed to retrieve data from the database", GetType().Name,
MethodBase.GetCurrentMethod().Name);
throw new HttpError(HttpStatusCode.InternalServerError);
}
关于c# - ASP.NET C# MySQL 查询执行失败时重试,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/46526488/