golang-samber-slog

Use ThresholdSamplingOption with a Tick, Threshold, and Rate, then wrap it as a Pipe middleware via NewMiddleware(). Place sampling as the outermost handler so dropped records never waste CPU on formatting.

Use slogmulti.Router() with Add(sentryHandler, slogmulti.LevelIs(slog.LevelError)) and a catch-all Loki handler, then call FirstMatch() so errors stop at the first matching route and skip sampling.

Fanout broadcasts every record to all handlers sequentially with latency equal to their sum. Router sends records to handlers matching predicates, while Pool load-balances each record to one handler with latency of a single handler.

Batch handlers like slog-datadog, slog-loki, slog-kafka, and slog-parquet buffer records internally and drop them on exit. Call handler.Stop(ctx), lokiClient.Stop(), writer.Close(), or buffer.Flush(true) during graceful shutdown.

Yes, sloggin.NewWithConfig accepts a Config struct with DefaultLevel, ClientErrorLevel, and ServerErrorLevel fields. Set ClientErrorLevel to Warn and ServerErrorLevel to Error without writing custom middleware.

AttrFromContext only reads values already present in the context, so without an HTTP middleware like slog-gin or slog-chi populating them, it silently returns nil. Install the middleware with WithRequestID enabled first.