FallbackGroup-target.md

Provides fallback-on-error.

Supported in .NET, Silverlight, Compact Framework and Mono.

Configuration Syntax

<targets>
  <target xsi:type="FallbackGroup" name="String" returnToFirstOnSuccess="Boolean">
    <target xsi:type="wrappedTargetType" ... />
    <target xsi:type="wrappedTargetType" ... />
    ...
    <target xsi:type="wrappedTargetType" ... />
  </target>
</targets>

Parameters

General Options

• name - Name of the target.

Fallback Options

• returnToFirstOnSuccess - Indicates whether to return to the first target after any successful write. Boolean. Default false

Performance Options

• OptimizeBufferReuse - Reduce logging overhead, by allowing buffer reuse. Default: True

  Introduced with NLog v4.4.2. Default became True with NLog v4.5

Example

Fallback to another mail if the mailserver is down

<target xsi:type="FallbackGroup" 
        name="mail"
        returnToFirstOnSuccess="true">
    <target xsi:type="Mail"
            name="mailserver1"
            subject="Layout"
            to="Layout"
            from="Layout"
            smtpServer="mx1.example.com" 
            smtpPort="Integer"
            layout="Layout" />
    <target xsi:type="Mail"
            name="mailserver2" 
            subject="Layout"
            to="Layout"
            from="Layout"
            smtpServer="mx2.example.com" 
            smtpPort="Integer"
            layout="Layout" />
</target>
<rules>
  <logger name="*" minlevel="Trace" writeTo="mail" />
</rules>