ScopeNested Layout Renderer - NLog/NLog GitHub Wiki

ScopeContext Nested States are stored in the thread execution context. Similar to "Nested Diagnostic Context" (NDC) in Log4j.

Platforms Supported: All (AsyncLocal is used for NetStandard and Net46, but older platforms uses Remoting.Messaging.CallContext)

Introduced with NLog 5.0 that merges MDC + MDLC + NDC + NDLC into an unified ScopeContext.

It enables one to assign a scope-name to the active scope (Ex. a request method-name). Then all logger-events created within the scoped logical context, can automatically capture the scope-name without needing to specify it with each LogEvent. The specified scope states will automatically flow together with async Tasks.

See also NLog Context and ${scopeproperty} and ${scopetiming} and ${scopeindent}

Configuration Syntax

${scopenested:bottomFrames=Integer:topFrames=Integer:separator=String}

Parameters

• bottomFrames - Number of bottom stack frames to be rendered. -1 is no limit. Integer. Default -1.
• topFrames - Number of top stack frames to be rendered. -1 is no limit. Integer. Default -1
• separator - Separator to be used for concatenating nested diagnostics context output. string. Default (space)
• format - Format string for conversion into string. Possible to use @ for Json-Array.
• culture - Format provider for conversion into string.

Examples

using (NLog.ScopeContext.PushNestedState("Outer Scope"))
{
   Logger.Info("Hello Outer");
   await InnerOperationAsync();
}

static async Task InnerOperationAsync()
{
    using (NLog.ScopeContext.PushNestedState("Inner Scope"))
    {
        Logger.Info("Hello Inner");
        await Task.Yield();
    }
}

The NLog Logger can also be used to update ScopeContext:

var logger = NLog.LogManager.GetCurrentClassLogger();
using (logger.PushScopeNested("Outer Scope"))
{
}

.NET Core logging

When using NLog.Extensions.Logging or NLog.Web.AspNetCore, you can also use BeginScope and more advanced options:

using (_logger.BeginScope("Outer Scope"))
{
   _logger.LogDebug("Start process {ProccessName}, "Main");
}

Indenting Log Messages

Indent log-messages based on how many nested levels in ScopeContext using ${scopeindent}

${scopeindent}${message}