v4.0.0

What's new in Serilog 4.0.0?

If you're deploying to .NET Framework, note that Serilog's assembly version number has been unpinned from the long-running historical 2.0.0 default, and now matches the package version precisely. If you encounter issues, ensure your build is generating valid assembly binding redirects.

Simple, robust, built-in batching support

Sinks that need batching functionality can now be easily written, without any additional package dependencies, by implementing IBatchedLogEventSink:

class MyBatchedSink: IBatchedLogEventSink
{
    public Task EmitBatchAsync(IReadOnlyCollection<LogEvent> batch)
    {
        // Send a batch of log events...
    }
}

Batched sinks can be added using WriteTo.Sink(IBatchedLogEventSink, ...) - they're given first-class consideration just like regular un-batched sinks.

The built-in batching implementation is based on System.Threading.Channels and draws on the original Serilog.Sinks.PeriodicBatching package (now in maintenance-mode), to provide a full-featured, efficient, async-native batching implementation.

Experimental dotted name capturing

By setting an experimental AppContext switch, message templates can be used to capture dotted names, which are required when using some logging schemas.

AppContext.SetSwitch("Serilog.Parsing.MessageTemplateParser.AcceptDottedPropertyNames", true);

Log.Information("Running as {user.name}", Environment.UserName);
// Captures {"user.name": "nblumhardt"}

While currently experimental and unsupported, this flag is intended to help the ecosystem evaluate and prepare for dotted name support in a future Serilog release.

Changes

• #2015 — breaking unpin assembly version (@nblumhardt)
• #2045 — breaking use case-insensitive matching for level overrides (@tillig)
• #2051 — breaking recognize UtcTimestamp as a built-in token in output templates (@MatthewHays)
• #1979 — add tests for ReusableStringWriter (@nblumhardt)
• #2016 — update TFMs (@nblumhardt, @bartelink)
• #2018 — add LogEvent.UnstableAssembleFromParts() (@nblumhardt)
• #2044 — build updates for compatibility (@tillig)
• #2027 — improve trimming annotations, compatibility switch for compiler-generated type support (@agocke)
• #2055 — introduce IBatchedLogEventSink and WriteTo.Sink(IBatchedLogEventSink) (@nblumhardt)
• #2060 — introduce LoggerSinkConfiguration.CreateSink() and redesign .Wrap() (@nblumhardt, @bartelink)
• #2063 — improve MessageTemplateParser performance, switch to allow . in captured property names (@nblumhardt)
• #2064 — make message template alignment parsing match spec (@Insomniak47)
• #2065 — allow any character except } in message template format specifiers (@Insomniak47)