log4net.tools 1.4.1

dotnet add package log4net.tools --version 1.4.1
NuGet\Install-Package log4net.tools -Version 1.4.1
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="log4net.tools" Version="1.4.1" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add log4net.tools --version 1.4.1
#r "nuget: log4net.tools, 1.4.1"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install log4net.tools as a Cake Addin
#addin nuget:?package=log4net.tools&version=1.4.1

// Install log4net.tools as a Cake Tool
#tool nuget:?package=log4net.tools&version=1.4.1

The ForwardingAppenderAsync wrapps any log4net appender putting the async buffer in front. The independent background worker is responsible for dequeuing of items from the buffer without blocking a client app.

Functional blocks

Thus waiting needing before for example to write a log in a database is delegated now and the only place where the client app is blocking is the stage of the in-memory enqueuing.

latency

The 'Dequeue' graph reflects the latency in microseconds of the RollingFileAppender (taken just as example) which works under the hood as the attached synchronous appender. A consumer is blocked only during the 'Enqueue' microseconds.

The approach allows:

  • to get the minimal blocking of the client app;
  • to turn any 'old' synchronous appender into the 'async' version easily without additional coding or recompile;
  • to eliminate concurrent waits on the internal lock section as the background worker is singlethreaded if no pooling is used;
  • to build aggregations over the buffer. For example, to drop log duplicates or generate stats on the fly.

Configurable logic:

XML Configuration

The example of the minimal configuration:

<appender name="ForwardingAppenderAsync" type="log4net.tools.ForwardingAppenderAsync">
    <appender-ref ref="RollingFileAppender" />
</appender>

The example of the advanced configuration:

<appender name="ForwardingAppenderAsync" type="log4net.tools.ForwardingAppenderAsync">
    <BufferSize value="1000"/>
    <Fix value="260"/>
    <BufferOverflowBehaviour value="RejectNew"/>
    <BufferClosingType value="DumpToLog"/>
    <WorkerPoolSize value="5"/>

    <appender-ref ref="DebugAppender" />
    <appender-ref ref="RollingFileAppender" />
    <appender-ref ref="AdoNetAppender" />
</appender>

More examples of the xml configuration are available here.

RollingFileAppender Benchmark

10K of sequential info-logs:
Method Mean
RollingFileAppender 1,742.69 ms
Buffered RollingFileAppender 180.728 ms
Forwarded RollingFileAppender 5.43 ms
10K of "parallel" (Parallel.For) info-logs:
Method Mean
RollingFileAppender 1,668.64 ms
Buffered RollingFileAppender 254.72 ms
Forwarded RollingFileAppender 4.45 ms

AdoNetAppender Benchmark

10K of sequential info-logs:
Method Mean
AdoNetAppender 3,336.11 ms
Forwarded AdoNetAppender 5.54 ms
10K of "parallel" (Parallel.For) info-logs:
Method Mean
AdoNetAppender 2,797.39 ms
Forwarded AdoNetAppender 4.62 ms

Worker Pool

The worker pool allows to improve throughput between the buffer and the attached appenders as it allows to dequeue the cached logs in parallel.

For example, the test with the RollingFileAppender shows the difference in intencity of 'dequeue' events: 1vs5_workers_rps

The latency is on the same level. We observe that more workers generate the denser 'Dequeue' graph. 1vs5_workers_latency

The buffer size grows not as steep as with the single threaded configuration as several workers together are more productive in processing of the benchmark stress load. 1vs5_workers_buffer

The 'WorkerPoolSize' configuration property defines the level of parallelism. The default value is '1' which corresponds to the 'single worker' scenario.

ForwardingAppenderAsyncWithMetrics

The appender grabs the metrics: LatencyUs, BufferSize, AllocatedBytes in addition to the ForwardingAppenderAsync functionality. The default output is Trace Info. Metrics bring some additional load so it is recommended to use the ForwardingAppenderAsync in scenarios where the minimum latency is required.

The example of the minimal xml configuration:

<appender name="Forwarding2RollingFileAppenderWithMetrics" type="log4net.tools.ForwardingAppenderAsyncWithMetrics, log4net.tools">
    <appender-ref ref="RollingFileAppender" />
</appender>

The example above uses "Trace" channel to output the metrics.

The example of the advanced xml configuration:

<appender name="Forwarding2RollingFileAppenderWithMetrics" type="log4net.tools.ForwardingAppenderAsyncWithMetrics, log4net.tools">
    <MetricsWriter type="log4net.tools.integration.MetricsCsvWriter, log4net.tools.integration">
        <CsvFilePath value="data.csv"/>
        <MaxRowCount value="100000"/>
    </MetricsWriter> 

    <BufferSize value="1000"/>
    <Fix value="260"/>
    <BufferOverflowBehaviour value="RejectNew"/>
    <BufferClosingType value="DumpToLog"/>
    <WorkerPoolSize value="5"/>

    <appender-ref ref="DebugAppender" />
    <appender-ref ref="RollingFileAppender" />
    <appender-ref ref="AdoNetAppender" />
</appender>

MetricsCsvWriter is available in the log4net.tools.integration package.

The example of the output:

DateTime            ,LatencyUs ,BufferSize ,CallerName ,AllocatedBytes
2021-05-04T11:49:22 ,2.00      ,76         ,DoAppend   ,5491168
2021-05-04T11:49:22 ,2.80      ,77         ,DoAppend   ,5587296
2021-05-04T11:49:22 ,318.80    ,77         ,Dequeue    ,5684840
2021-05-04T11:49:22 ,2.40      ,77         ,DoAppend   ,1269424
2021-05-04T11:49:22 ,2.50      ,78         ,DoAppend   ,1367776
2021-05-04T11:49:22 ,2.00      ,79         ,DoAppend   ,1466128
2021-05-04T11:49:22 ,2.30      ,80         ,DoAppend   ,1564480
2021-05-04T11:49:22 ,1.50      ,81         ,DoAppend   ,1662832
2021-05-04T11:49:22 ,273.80    ,81         ,Dequeue    ,1752992

The python notebook to analyze the metrics.

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
.NET Core netcoreapp2.0 was computed.  netcoreapp2.1 was computed.  netcoreapp2.2 was computed.  netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard2.0 is compatible.  netstandard2.1 was computed. 
.NET Framework net461 was computed.  net462 was computed.  net463 was computed.  net47 was computed.  net471 was computed.  net472 was computed.  net48 was computed.  net481 was computed. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen40 was computed.  tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.
  • .NETStandard 2.0

NuGet packages (1)

Showing the top 1 NuGet packages that depend on log4net.tools:

Package Downloads
log4net.tools.integration

Tools for log4net: - MetricsCsvWriter writes logging metrics in a csv file.

GitHub repositories

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Version Downloads Last updated
1.4.1 6,447 5/12/2021
1.4.0 305 5/11/2021
1.3.0 504 5/4/2021
1.2.0 298 4/30/2021
1.1.0 309 4/28/2021
1.0.1 331 4/27/2021
1.0.0 289 4/26/2021

-  fix the buffer overflow handling