Glg

Glg is a high-speed, simple logging library for Go designed to output large volumes of logs at high speed with minimal overhead.

Overview

In high-throughput systems such as vector search engines and ad delivery platforms, logging can become a significant bottleneck if the logger introduces contention or allocations. Glg was designed from scratch to eliminate these bottlenecks, providing leveled logging with colorized output while maintaining extreme performance.

Key Features

• High-speed output — optimized for throughput with minimal overhead per log call
• Leveled logging — supports standard levels (TRACE, DEBUG, INFO, WARN, ERROR, FATAL)
• Colorized output — automatic color coding by log level for terminal readability
• Custom writer support — plug in any io.Writer for flexible log routing
• Printf and Println style — familiar Go formatting for log messages
• Thread-safe — safe for concurrent use from multiple goroutines
• Customizable log format — configurable timestamp and output format

Usage

import "github.com/kpango/glg"

// Simple logging
glg.Info("server started")
glg.Debugf("processing request: %s", requestID)
glg.Error("connection failed")

// Custom configuration
glg.Get().
    SetMode(glg.STD).
    SetLevel(glg.INFO)

Production Use

Glg is not merely an individual open-source development — it has become an established standard library widely used within LY Corporation in mission-critical Go services, including:

• Vald — distributed vector search engine core components
• Athenz-related products — authentication and authorization infrastructure
• Ad delivery infrastructure — high-throughput advertising platform

Links

• GitHub