我和一位同事的任务都是为 Azure 表存储寻找连接重试逻辑。经过一番搜索,我发现了这个非常酷的 Enterprise Library 套件,其中包含Microsoft.Practices.TransientFaultHandling
命名空间。
在几个代码示例之后,我最终创建了一个重试策略,并使用的回调处理程序Incremental
包装了我们的一个存储调用:retryPolicy
ExecuteAction
/// <inheritdoc />
public void SaveSetting(int userId, string bookId, string settingId, string itemId, JObject value)
{
// Define your retry strategy: retry 5 times, starting 1 second apart, adding 2 seconds to the interval each retry.
var retryStrategy = new Incremental(5, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(2));
var storageAccount = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting(StorageConnectionStringName));
try
{
retryPolicy.ExecuteAction(() =>
{
var tableClient = storageAccount.CreateCloudTableClient();
var table = tableClient.GetTableReference(SettingsTableName);
table.CreateIfNotExists();
var entity = new Models.Azure.Setting
{
PartitionKey = GetPartitionKey(userId, bookId),
RowKey = GetRowKey(settingId, itemId),
UserId = userId,
BookId = bookId.ToLowerInvariant(),
SettingId = settingId.ToLowerInvariant(),
ItemId = itemId.ToLowerInvariant(),
Value = value.ToString(Formatting.None)
};
table.Execute(TableOperation.InsertOrReplace(entity));
});
}
catch (StorageException exception)
{
ExceptionHelpers.CheckForPropertyValueTooLargeMessage(exception);
throw;
}
}
}
感觉很棒,我去给我的同事看,他得意地指出我们可以做同样的事情而不必包含企业库,因为CloudTableClient
对象已经有一个重试策略的设置器。他的代码最终看起来像:
/// <inheritdoc />
public void SaveSetting(int userId, string bookId, string settingId, string itemId, JObject value)
{
var storageAccount = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting(StorageConnectionStringName));
var tableClient = storageAccount.CreateCloudTableClient();
// set retry for the connection
tableClient.RetryPolicy = new ExponentialRetry(TimeSpan.FromSeconds(2), 3);
var table = tableClient.GetTableReference(SettingsTableName);
table.CreateIfNotExists();
var entity = new Models.Azure.Setting
{
PartitionKey = GetPartitionKey(userId, bookId),
RowKey = GetRowKey(settingId, itemId),
UserId = userId,
BookId = bookId.ToLowerInvariant(),
SettingId = settingId.ToLowerInvariant(),
ItemId = itemId.ToLowerInvariant(),
Value = value.ToString(Formatting.None)
};
try
{
table.Execute(TableOperation.InsertOrReplace(entity));
}
catch (StorageException exception)
{
ExceptionHelpers.CheckForPropertyValueTooLargeMessage(exception);
throw;
}
}
我的问题 :
除了实现之外,这两种方法之间是否有任何重大区别?它们似乎都实现了相同的目标,但是在某些情况下使用一个比另一个更好吗?