例外:从DocumentDB查询时出现Microsoft.Azure.Documents.RequestRateTooLargeException

y查询是这样的

this.ProcessRequestSync(() => this.Client.CreateDocumentQuery(this.DocumentDBCollectionLink).Where(d => d.name.Equals(name) && d.code.Equals(code) && d.Type.Equals(this.documentType) && d.CreatedBy.Equals(myName).ToList());

 public dynamic ProcessRequestSync(Func getRequest)
{
    var delay = TimeSpan.Zero;
    var minDelayTime = new TimeSpan(0, 0, 1);
    for (;;)
    {
        try
        {
            Thread.Sleep(delay);
            return getRequest();
        }
        catch (DocumentClientException documentClientException)
        {
            var statusCode = (int)documentClientException.StatusCode;
            if (statusCode == 429 || statusCode == 503)
            {
                string errorMessage = string.Format("failed at DocumentDB with {0} status and {1} retry time", statusCode, documentClientException.RetryAfter);
                this.Logger.Log(errorMessage );

                // Back off if the request rate is too large or the service is temporarily unavailable
                delay = TimeSpan.Compare(documentClientException.RetryAfter, minDelayTime) >= 0 ? documentClientException.RetryAfter: minDelayTime;
            }
            else
            {
                throw;
            }
        }
    }
}

这是requestRateTooLarge异常引发时重试逻辑的方法.

我不确定,它是否正常工作,

我收到异常:Microsoft.Azure.Documents.RequestRateTooLargeException同时查询和插入大约4000条记录,

我使用相同的重试逻辑进行插入,其工作正常.我没有收到任何错误,也成功插入所有记录,但无法获取查询数据.

1> Aravind Kris..：

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您还需要一个用于AggregateException的catch块,并检查AggregateException.InnerException是否为DocumentClientException并对StatusCode == 429执行相同的检查.由于查询执行是异步的,您可能会在AggregateException中包含限制异常.

如果您可以发布完整的repro,我们可以明确地确定问题.

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另外值得注意的是,在处理限制异常时不要等待Timespan.Zero.而是查看你得到的响应,它将具有retry-after值.等待那段时间.

2> BMac..：

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基于@aravind Ramachandra和@Ryan CrawCour上面/下面的答案,这就是我用来解决问题的方法.

    public async Task SaveToDocDb(dynamic jsonDocToSave)
    {

        using (var client = new DocumentClient(endpoint, authKey))
        {
            var queryDOne= false;
            while (!queryDone)
            {
                try
                {
                    await client.CreateDocumentAsync(docCollectionlink, jsonDocToSave);
                    queryDOne= true; 
                }
                catch (DocumentClientException documentClientException)
                {
                    var statusCode = (int)documentClientException.StatusCode;
                    if (statusCode == 429 || statusCode == 503)   
                        Thread.Sleep(documentClientException.RetryAfter);
                    else
                        throw;
                }
                catch (AggregateException aggregateException)
                {
                    if(aggregateException.InnerException.GetType() == typeof(DocumentClientException)){

                        var docExcep = aggregateException.InnerException as DocumentClientException;
                        var statusCode = (int)docExcep.StatusCode;
                        if (statusCode == 429 || statusCode == 503)
                            Thread.Sleep(docExcep.RetryAfter);
                        else
                            throw;
                    }
                     else 
                       throw;
                }
            }
        }
    }

---

@core虽然理论上你是对的,但实际上我已经将这段代码生产了近一年了,并且在工作中设置了一个杀戮时间 - 它从未达到过这个杀戮时间,因此意味着你的循环场景不可能发生在实践中.无论如何,对于其他人来说,建议微妙的修复/编辑答案,而不是声明完整的答案"坏代码"可能是有用的!