IO::Metrics

Extract I/O metrics from the host system, specifically listen queue statistics.

Please see the project documentation for more details.

• Getting Started - This guide explains how to use io-metrics to capture listener queue statistics from the host operating system.

Please see the project releases for all releases.

• Breaking Rename Listener fields: queue_size → queued_count, active_connections → active_count.
• Introduce Listener#close_wait_count: number of accepted connections in CLOSE_WAIT state (peer has closed; application still processing).

• Fixed queue_size under-reporting when multiple SO_REUSEPORT sockets share the same address — queue depths are now accumulated across all sockets rather than overwritten by the last one.
• Linux Listener#active_connections for TCP no longer counts sockets that are still in the kernel accept queue (those remain in queue_size). Counts now match the usual “past accept()” meaning and align with tools such as Raindrops’ ListenStats#active.

• Breaking IO::Metrics::Listener.capture returns an Array of Listener rows instead of a Hash keyed by address string.
• Each Listener has address (Addrinfo for TCP or Unix), queue_size, and active_connections. Listener.zero sets address to nil. JSON uses Addrinfo#inspect_sockaddr for address, or null when absent.

We welcome contributions to this project.

1. Fork it.
2. Create your feature branch (git checkout -b my-new-feature).
3. Commit your changes (git commit -am 'Add some feature').
4. Push to the branch (git push origin my-new-feature).
5. Create new Pull Request.

To run the test suite:

bundle exec sus

To make a new release:

bundle exec bake gem:release:patch # or minor or major

In order to protect users of this project, we require all contributors to comply with the Developer Certificate of Origin. This ensures that all contributions are properly licensed and attributed.

This project is best served by a collaborative and respectful environment. Treat each other professionally, respect differing viewpoints, and engage constructively. Harassment, discrimination, or harmful behavior is not tolerated. Communicate clearly, listen actively, and support one another. If any issues arise, please inform the project maintainers.