Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

0.3.0 - 2026-05-25

[:loki_logger_handler, :format, :error] telemetry event - emitted when an event cannot be formatted and a fallback entry is buffered instead

A single malformed log event can no longer remove the handler from :logger. Formatting now runs inside a rescue: on failure the handler buffers a best-effort fallback entry and emits a telemetry event rather than letting the exception propagate and disable the handler. The formatter also degrades gracefully on unexpected message, report_cb, and timestamp shapes instead of raising.

Telemetry events for buffer monitoring:
- [:loki_logger_handler, :buffer, :insert] - emitted after buffering a log entry
- [:loki_logger_handler, :buffer, :remove] - emitted after sending and removing entries

Erlang :logger handler implementation for Grafana Loki
Configurable storage strategy:
- :disk (default) - CubDB-backed persistent storage that survives restarts
- :memory - ETS-backed in-memory storage for higher throughput
Configurable label extraction from log metadata
Structured metadata support (Loki 2.9+)
Dual threshold batching (time interval and batch size)
Exponential backoff on Loki unavailability
Buffer overflow protection (drops oldest logs when full)
Multiple handler support for different Loki endpoints
LokiLoggerHandler.FakeLoki test server with ephemeral port support
Flush API for graceful shutdown
Runtime configuration updates