Ourios

οὔριος — the fair wind that fills a ship’s sail.

Ourios is a log storage and query backend built on Apache Parquet, a Drain-derived online template miner, and Apache DataFusion. The thesis: Parquet + template mining + DataFusion collapses the inverted index, the compression layer, the storage tier, and the query engine into one stack of off-the-shelf parts plus thin glue. Log lines collapse to (template_id, params) at ingest — a logical 50–200× reduction whose payoff is query pruning (a selective query reads a handful of row groups instead of scanning the corpus), not on-disk bytes that beat a byte codec. Our job is the glue, plus the honest handling of the places where template mining can go wrong.

The repository README is the short front door; this book is the design record and the depth behind it.

Project status

Pre-release, under active RFC-driven development. The full path — OTLP in; WAL, miner, Parquet on object storage; logs-DSL / DataFusion queries out — is implemented and tested behind RFC acceptance gates, and the performance thesis is measured (including against Grafana Loki) in Benchmarks. Signed pre-release binaries, container images, and a Helm chart exist, but interfaces and the on-disk schema can still move: treat everything as pre-1.0.

How this book is organised

• Getting started — run the single binary, configure it, deploy it with Docker or Helm, and lock it down before a listener leaves localhost.
• Architecture — the load-bearing reading: OTLP’s log data model vs. the miner’s view of it, hazards (where projects in this space die, and how we won’t), verification (how an RFC criterion becomes a red-gate test becomes a green one), and the glossary.
• Benchmarks — the thesis gates, stated so they could falsify the project, and every measurement against them with run IDs and caveats; plus the roadmap.
• RFCs — every subsystem is specified before it is built. Each RFC pins Given / When / Then acceptance scenarios and climbs a maturity ladder (drafted → specified → red → green → validated → accepted); the frontmatter status tells you how much to trust it.
• Talks — lecture-length explanations of the ideas behind the RFCs, for when you want the background rather than the specification.

Contributions, RFC discussion, and push-back on the invariants are all welcome — CONTRIBUTING.md and CLAUDE.md in the repository root carry the governing conventions, including the project’s intentionally fully AI-assisted development process under human maintainer review.