go-samber-slog

Use slogmulti.Router() with predicates: add the Sentry handler with slogmulti.LevelIs(slog.LevelError) and the Loki handler for other levels. Add FirstMatch() so errors don't fall through to the sampled path, and always include a catch-all handler to avoid silently dropping records.

Use slog-sampling's ThresholdSamplingOption to log the first N records per interval, then sample at a rate. Place sampling as the outermost pipeline stage, and use a FirstMatch router so Warn/Error records bypass sampling entirely and always reach their sink.

Yes, dedicated packages exist: slog-gin, slog-echo, slog-fiber, slog-chi, plus slog-http for net/http. All share a Config struct with level mapping, body capture, trace ID options, and filters like IgnorePath and IgnoreStatus.

Batch handlers like slog-datadog, slog-loki, slog-kafka, and slog-parquet buffer records internally. You must call their shutdown methods (handler.Stop(ctx), lokiClient.Stop(), writer.Close(), buffer.Flush(true)) on exit or buffered logs are discarded.

Fanout sends every record to all handlers sequentially (latency is the sum of all handlers). Router sends records only to handlers whose predicates match. Pool distributes each record to one handler for load balancing, keeping latency at a single handler's cost.

Apply slog-formatter as a Pipe middleware with PIIFormatter and IPAddressFormatter so all downstream handlers receive clean attributes. Place formatting after sampling but before routing so dropped records don't waste formatting CPU.