slogsampling

Slog sampling policy

A middleware that samples incoming records which caps the CPU and I/O load of logging while attempting to preserve a representative subset of your logs.

See also:

• slog-multi: slog.Handler chaining, fanout, routing, failover, load balancing...
• slog-formatter: slog attribute formatting
• slog-sampling: slog sampling policy
• slog-gin: Gin middleware for slog logger
• slog-echo: Echo middleware for slog logger
• slog-fiber: Fiber middleware for slog logger
• slog-datadog: A slog handler for Datadog
• slog-rollbar: A slog handler for Rollbar
• slog-sentry: A slog handler for Sentry
• slog-syslog: A slog handler for Syslog
• slog-logstash: A slog handler for Logstash
• slog-fluentd: A slog handler for Fluentd
• slog-graylog: A slog handler for Graylog
• slog-loki: A slog handler for Loki
• slog-slack: A slog handler for Slack
• slog-telegram: A slog handler for Telegram
• slog-mattermost: A slog handler for Mattermost
• slog-microsoft-teams: A slog handler for Microsoft Teams
• slog-webhook: A slog handler for Webhook
• slog-kafka: A slog handler for Kafka

🚀 Install

go get github.com/samber/slog-sampling

Compatibility: go >= 1.20.3

This library is v0 and follows SemVer strictly. On slog final release (go 1.21), this library will go v1.

No breaking changes will be made to exported APIs before v1.0.0.

💡 Usage

GoDoc: https://pkg.go.dev/github.com/samber/slog-sampling

The sampling middleware can be used standalone or with slog-multi helper.

Handler options

type Option struct {
	// This will log the first `First` log entries with the same level and message
	// in a `Tick` interval as-is. Following that, it will allow through
	// every `Thereafter`th log entry with the same level and message in that interval.
	Tick       time.Duration
	First      uint64
	Thereafter uint64

    // Optional hooks
	OnAccepted func(context.Context, slog.Record)
	OnDropped  func(context.Context, slog.Record)
}

If Thereafter is zero, the middleware will drop all log entries after the first First records in that interval.

Using slog-multi

import (
	slogmulti "github.com/samber/slog-multi"
	slogsampling "github.com/samber/slog-sampling"
	"golang.org/x/exp/slog"
)

// Will print the first 10 entries having the same level+message, then every 10th messages until next interval.
option := slogsampling.Option{
    Tick:       5 * time.Second,
    First:      10,
    Thereafter: 10,

    OnAccepted: func(context.Context, slog.Record) {
        // ...
    },
    OnDropped: func(context.Context, slog.Record) {
        // ...
    },
}

logger := slog.New(
    slogmulti.
        Pipe(option.NewSamplingMiddleware()).
        Handler(slog.NewJSONHandler(os.Stdout)),
)

Standalone

import (
	slogmulti "github.com/samber/slog-multi"
	slogsampling "github.com/samber/slog-sampling"
	"golang.org/x/exp/slog"
)

// Will print the first 10 entries having the same level+message, then every 10th messages until next interval.
option := slogsampling.Option{
    Tick:       5 * time.Second,
    First:      10,
    Thereafter: 10,

    OnAccepted: func(context.Context, slog.Record) {
        // ...
    },
    OnDropped: func(context.Context, slog.Record) {
        // ...
    },
}

logger := slog.New(
    option.NewSamplingMiddleware()(
        slog.NewJSONHandler(os.Stdout),
    ),
)

🤝 Contributing

• Ping me on twitter @samuelberthe (DMs, mentions, whatever :))
• Fork the project
• Fix open issues or request new features

Don't hesitate ;)

# Install some dev dependencies
make tools

# Run tests
make test
# or
make watch-test

👤 Contributors

💫 Show your support

Give a ⭐️ if this project helped you!

📝 License

Copyright © 2023 Samuel Berthe.

This project is MIT licensed.