hlogger

Hlogger is a term used in software development to describe a family of lightweight, hierarchical logging libraries or services that emit structured log records and maintain contextual information across an application. In practice, hlogger implementations provide an interface for generating messages at various severity levels, and attach metadata that describes the source module, operation, or request context.

Core ideas include hierarchical contexts, allowing child loggers to inherit fields from their parents, and the ability to enable or disable logging at different scopes. Most hlogger libraries support multiple output backends such as console, files, and centralized log servers, and allow configuration of formats, message structures, and rotation policies.

Design goals emphasize low runtime overhead, thread safety, and configurability. They typically offer pluggable backends, asynchronous or batched delivery, and facilities for filtering and enrichment of log records. Structured logging is common, with messages carried as key-value data rather than free-form strings.

Typical usage includes creating a root logger at program startup, creating child loggers per module or component, and using context scopes to attach request or transaction identifiers. This enables richer search and correlation in log storage systems.

The name hlogger appears in multiple open-source projects across programming ecosystems, and there is no single canonical specification. Some repositories target specific languages or runtimes, while others describe general logging patterns that can be implemented under the hlogger banner.

See also: logging library, structured logging, hierarchical logging, log levels, log backend.