当文件达到 5.4MB 时，自定义 log4net azure blob appender 停止记录

Question

我正在使用下面的附加程序通过 Log4Net 将我们的日志消息通过管道传输到 Azure。一切正常，直到 blob 文件达到 5.4MB 的大小。从那时起，不再有日志附加到日志文件。

这是什么原因造成的？我该如何解决这个问题？

namespace Digicreate.Core.Infrastructure.Logging
{
using System;
using System.Configuration;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

using log4net.Appender;
using log4net.Config;
using log4net.Core;

using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Blob;

// ReSharper disable once UnusedMember.Global
// justification: used in log4net configuration file
public class AzureBlobTxtFileAppender : BufferingAppenderSkeleton
{
    private CloudStorageAccount _account;
  ...removed unimportant code...

            protected override void SendBuffer(LoggingEvent[] events)
    {
        var appendBlobReference = _cloudBlobContainer.GetAppendBlobReference(Filename(DirectoryName));
        if (!appendBlobReference.Exists())
        {
            appendBlobReference.CreateOrReplace();
        }

        Parallel.ForEach(events, ProcessEvent);
    }

    private static string Filename(string directoryName)
    {
        return $"{directoryName}/{DateTime.Today.ToString("yyyy_MM_dd", DateTimeFormatInfo.InvariantInfo)}.log.txt";
    }

    private void ProcessEvent(LoggingEvent loggingEvent)
    {
        using (var memoryStream = new MemoryStream())
        {
            using (var streamWriter = new StreamWriter(memoryStream, Encoding.UTF8, 1024, true))
            {
                Layout.Format(streamWriter, loggingEvent);
                streamWriter.Flush();
            }

            memoryStream.Position = 0;

            _cloudBlobContainer
                .GetAppendBlobReference(Filename(DirectoryName))
                .AppendBlock(memoryStream);
        }
    }
  }
}

Answer 1

根据追加块 documentation，您可能会遇到一个 blob 的 50,000 块限制。确保在提交到 Blob 之前检查已提交块的数量：

var blockCount = _cloudBlobContainer.GetAppendBlobReference(Filename(DirectoryName))
                                    .Properties
                                    .AppendBlobCommittedBlockCount;

并确保它不超过 50000。

当文件达到 5.4MB 时，自定义 log4net azure blob appender 停止记录

Custom log4net azure blob appender stops logging when a file reaches 5.4MB

c#

log4net

azure-blob-storage