KO | EN

GitLite

Minimalist Open Source Repository Search Engine

gitlite — search

#dsh #dsh-plugin #typescript #developer-tools #claude-code #ai-agent #codex #deepseek-harness #ai-agents #cli #react #mcp

janus

★ 70 Open GitHub ↗

Experimental implementation of the Distributed Aggregation Protocol (DAP) specification.

// repository documentation

Was this content helpful?

★ 0 (0 ratings)

# janus
[![Build Status]][actions]

[Build Status]: https://github.com/divviup/janus/workflows/ci-build/badge.svg
[actions]: https://github.com/divviup/janus/actions?query=branch%3Amain

Janus is an implementation of the [Distributed Aggregation Protocol (DAP)
specification](https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/). Currently
it supports VDAFs with trivial aggregation parameters only, e.g. Prio3. VDAFs
with nontrivial aggregation parameters (e.g. Mastic) are not yet supported.

Janus is currently in active development.

- [janus](#janus)
  - [Draft versions and release branches](#draft-versions-and-release-branches)
    - [`draft-ietf-ppm-dap-07` errata](#draft-ietf-ppm-dap-07-errata)
    - [`draft-ietf-ppm-dap-09` errata](#draft-ietf-ppm-dap-09-errata)
  - [Versioning and Stability](#versioning-and-stability)
  - [Building](#building)
    - [Container image](#container-image)
  - [Minimum Supported Rust Version (MSRV)](#minimum-supported-rust-version-msrv)
  - [Running tests](#running-tests)
    - [inotify limits](#inotify-limits)
  - [Deploying Janus](#deploying-janus)
  - [Cargo features](#cargo-features)

## Draft versions and release branches

The `main` branch is under continuous development and will usually be partway
between DAP drafts. Janus uses stable release branches to maintain
implementations of different DAP draft versions. Rust crates and container
images with versions `x.y.z` are released from a corresponding `release/x.y`
branch.

| Git branch | Draft version | TaskProv version | Conforms to protocol? | Status |
| ---------- | ------------- | ---------------- | --------------------- | ------ |
| `release/0.1` | [`draft-ietf-ppm-dap-01`][dap-01] | ? | Yes | Unmaintained as of December 7, 2022 |
| `release/0.2` | [`draft-ietf-ppm-dap-02`][dap-02] | ? | Yes | Unmaintained as of July 13, 2023 |
| `release/0.3` | [`draft-ietf-ppm-dap-03`][dap-03] | ? | Yes | Unmaintained as of February 6, 2023 |
| `release/0.4` | [`draft-ietf-ppm-dap-04`][dap-04] | ? | Yes | Unmaintained as of May 24, 2023 |
| `release/0.subscriber-01` | [`draft-ietf-ppm-dap-02`][dap-02] plus extensions | ? | No | Unmaintained as of November 1, 2023 |
| `release/0.5` | [`draft-ietf-ppm-dap-04`][dap-04] | ? | Yes | Unmaintained as of June 24, 2024 |
| `release/0.6` | [`draft-ietf-ppm-dap-07`][dap-07] | ? | Yes, [with errata](#draft-ietf-ppm-dap-07-errata) | Unmaintained as of June 24, 2024 |
| `release/0.7` | [`draft-ietf-ppm-dap-09`][dap-09] | [`draft-ietf-ppm-dap-taskprov-03`][taskprov-03] | Yes, [with errata](#draft-ietf-ppm-dap-09-errata) | Supported |
| `release/0.8` | [`draft-ietf-ppm-dap-15`][dap-15] | [`draft-ietf-ppm-dap-taskprov-03`][taskprov-03] | Yes | Unmaintained as of August 27th, 2025 |
| `main` | [`draft-ietf-ppm-dap-18`][dap-gh][^1] | [`draft-ietf-ppm-dap-taskprov-04`][taskprov-gh][^2] | No | Supported |

Note that not every DAP draft has been implemented.

[^1]: `draft-ietf-ppm-dap-18` has not yet been published. Janus implements the
      tip of the specification's `main` branch, which is expected to soon become
      the 18th draft.
[^2]: `draft-ietf-ppm-dap-taskprov-04` has not yet been published. Janus
      implements the tip of the specification's `main` branch, which is expected
      to soon become the 18th draft.

[dap-01]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/01/
[dap-02]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/02/
[dap-03]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/03/
[dap-04]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/04/
[dap-07]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/07/
[dap-09]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/09/
[dap-15]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap/15/
[dap-gh]: https://github.com/ietf-wg-ppm/draft-ietf-ppm-dap
[taskprov-03]: https://datatracker.ietf.org/doc/draft-ietf-ppm-dap-taskprov/03/
[taskprov-gh]: https://github.com/ietf-wg-ppm/draft-ietf-ppm-dap-taskprov

### `draft-ietf-ppm-dap-07` errata

There is a bug in Janus' `release/0.6` branch wherein `PrepareResp` messages are
incorrectly encoded, making Janus incompatible with other DAP Aggregator
implementations.

See [issue #2466](https://github.com/divviup/janus/issues/2466) for details.

### `draft-ietf-ppm-dap-09` errata

Janus' `release/0.7` branch contains the following issues which cause it to skew
from the behavior specified in the DAP specification:

* When acting as a Leader aggregator, Janus responds to successful upload
  requests with an HTTP 200 OK status rather than an HTTP 201 Created status.
  The suggested workaround is for clients to accept any HTTP status code in the
  2xx range as success. See [issue
  #3483](https://github.com/divviup/janus/issues/3483) for details.

## Versioning and Stability

Janus follows [semantic versioning](https://semver.org/). Because we are at
major version 0, we increment the minor version number for breaking changes, and
increment the patch version for new features and backwards-compatible bug fixes.

What is considered a breaking change depends on the crate. The following crates
are stable on their Rust API:
- `janus_collector`
- `janus_client`
- `janus_messages`

`janus_core` is published to crates.io, but has no stability guarantees. It
should not be depended on directly. If you find yourself needing to depend
on it directly while using any other Janus crates, open a bug report.

The following crates are stable on their external configuration, CLI arguments,
and HTTP API. Their Rust API may arbitrarily change and should not be depended
on. They are not published to crates.io.
- `janus_aggregator`
- `janus_tools`

Any other crates not mentioned have no stability guarantees whatsoever.

## Building

To build Janus, execute `cargo build`.

### Container image

To build container images, run `docker buildx bake --load`. This will produce
images tagged `janus_aggregator`, `janus_garbage_collector`,
`janus_aggregation_job_creator`, `janus_aggregation_job_driver`,
`janus_collection_job_driver`, `janus_cli`, `janus_db_migrator`,
`janus_interop_client`, `janus_interop_aggregator`, and
`janus_interop_collector` by default.

Pre-built container images are available at
[us-west2-docker.pkg.dev/divviup-artifacts-public/janus](https://us-west2-docker.pkg.dev/divviup-artifacts-public/janus).

## Minimum Supported Rust Version (MSRV)

We support the latest stable version of Rust, at time of release, and the two
preceding minor versions.

## Running tests

Tests require that [`docker`](https://www.docker.com) and
[`kind`](https://kind.sigs.k8s.io) be installed on the machine running the tests
and in the `PATH` of the test-runner's environment. The `docker` daemon must be
running. See `core/src/test_util/kubernetes.rs` for the version of Kind and the
corresponding node image currently in use.

To run Janus tests, execute `cargo test`. To run tests on Docker images, execute
`cargo xtask test-docker`.

Note that `podman` is not an acceptable substitute for `docker`. There are
subtle incompatibilities between the two that will cause tests to fail.

### inotify limits

If you experience issues with tests using Kind on Linux, you may need to [adjust
inotify sysctls][inotify]. Both systemd and Kubernetes inside each Kind node
make use of inotify. When combined with other services and desktop applications,
they may exhaust per-user limits.

[inotify]: https://kind.sigs.k8s.io/docs/user/known-issues/#pod-errors-due-to-too-many-open-files

## Deploying Janus

See the [documentation on deploying Janus](docs/DEPLOYING.md) for details about
its configuration and operation.

## Cargo features

`janus_core` has the following features available.

* `database`: Enables implementations of `postgres_types::ToSql` and
  `postgres_types::FromSql` on `janus_core::Interval`.
* `test-util`: Enables miscellaneous test-only APIs. This should not be used
  outside of tests, and any such APIs do not carry any stability guarantees.

`janus_aggregator` has the following features available.

* `otlp`: Enables OTLP exporter support for both metrics and tracing. See the
  [metrics](docs/CONFIGURING_METRICS.md) and
  [tracing](docs/CONFIGURING_TRACING.md) documentation for configuration
  instructions.
* `prometheus`: Enables a Prometheus metrics exporter; see the
  [documentation](docs/CONFIGURING_METRICS.md) for configuration instructions.
* `test-util`: Enables miscellaneous test-only APIs. This should not be used
  outside of tests, and any such APIs do not carry any stability guarantees.
* `tokio-console`: Enables a tracing subscriber and server to support
  [`tokio-console`](https://github.com/tokio-rs/console). See the
  [documentation](docs/CONFIGURING_TOKIO_CONSOLE.md) for configuration
  instructions.

janus

Explore Similar Repositories

Was this content helpful?

Recent Feedback

Download README