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Migration from Microsoft.Extensions.Logging

This guide helps teams move from Microsoft.Extensions.Logging (MEL) patterns to XenoAtom.Logging.

Scope of compatibility

XenoAtom.Logging is not a MEL provider/bridge today.
Migration is API-level: update startup configuration and logging call sites.

Quick mapping

MEL concept	XenoAtom.Logging concept
ILogger<TCategoryName>	Logger from LogManager.GetLogger("Category")
ILoggerFactory / provider pipeline	LogManager.Initialize(...) with configured writers
LogLevel	LogLevel
EventId	LogEventId
BeginScope(...)	BeginScope(LogProperties)
LoggerMessageAttribute	[LogMethod]
appsettings provider config	LogManagerConfig + code configuration

Minimal migration example

MEL

builder.Services.AddLogging(logging =>
{
    logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Information);
    logging.AddConsole();
});

XenoAtom.Logging

using XenoAtom.Logging;
using XenoAtom.Logging.Writers;

var config = new LogManagerConfig
{
    RootLogger =
    {
        MinimumLevel = LogLevel.Info,
        Writers =
        {
            new StreamLogWriter(Console.OpenStandardOutput())
        }
    }
};

LogManager.Initialize(config);

Message templates and source generation

MEL LoggerMessageAttribute:

[LoggerMessage(EventId = 1, Level = LogLevel.Information, Message = "Processing item {ItemId}")]
public static partial void ProcessingItem(ILogger logger, int itemId);

XenoAtom.Logging equivalent:

using XenoAtom.Logging;

public static partial class AppLog
{
    [LogMethod(LogLevel.Info, "Processing item {itemId}", EventId = 1)]
    public static partial void ProcessingItem(Logger logger, int itemId);
}

See Source-generated Logging for full generator rules.

Scopes and structured data

MEL scope style:

using (_logger.BeginScope("Request {RequestId}", requestId))
{
    _logger.LogInformation("Handling request");
}

XenoAtom.Logging style:

using (logger.BeginScope(new LogProperties { ("RequestId", requestId) }))
{
    logger.Info("Handling request");
}

Per-message properties are explicit and allocation-aware:

logger.Info(
    properties: new LogProperties { ("UserId", 42), ("Feature", "checkout") },
    msg: "Validation failed");

Async behavior differences

MEL provider behavior depends on each provider implementation.
XenoAtom.Logging exposes explicit async queue settings:

• InitializeForAsync(config)
• AsyncLogMessageQueueCapacity
• OverflowMode (Drop, DropAndNotify, Block, Allocate)
• AsyncErrorHandler

Use Block when correctness is more important than producer latency.

Recommended migration strategy

1. Introduce LogManager startup/shutdown lifecycle.
2. Replace logger injection with Logger access (LogManager.GetLogger(...)) at app entry points/services.
3. Migrate high-traffic logs first to [LogMethod] or interpolated APIs.
4. Move sinks to FileLogWriter/JsonFileLogWriter/TerminalLogWriter as needed.
5. Validate throughput and behavior with Benchmarks and app-specific load tests.

Common pitfalls

• Forgetting LogManager.Shutdown() on process exit (can lose buffered writes).
• Using Drop overflow in critical audit paths.
• Mutating config/filter collections from multiple threads without synchronization.

See Thread Safety and Shutdown Semantics for operational guidance.