Files
tsunagi/vendor/iroh/DEVELOPMENT.md
T
Aleksandr Bogomiakov 2b0c938487 Bound iroh path retries to prevent multi-connection OOM
A long-running rc.33 daemon reached OOM with roughly 22 GiB resident and
24 GiB swapped. Live inspection found 40 GiB and 10/20 GiB anonymous
container mappings; the active worker stack and tracing metadata identified
iroh's scheduled path-open retry loop. In iroh 1.2.0 every failed connection
requeues the same path, while each retry visits every connection again.
Separate control and data connections multiply the queue geometrically.

Vendor the published iroh 1.2.0 source and select it with a workspace Cargo
patch. Deduplicate retry admission and cap distinct pending paths at 64,
evicting the oldest before inserting a new candidate. Keep the current and
next retry batches bounded without combining control/data connections or
changing wire protocols, identity derivation, authentication or state.
Document source provenance, the live evidence and removal conditions.
Upstream PR 4551 merged on October 6, but inspection of the official 1.3.0
crate still shows the unconditional enqueue, so that upgrade alone is not
a fix. No version bump, release tag or installed-service change.

The default workspace suite includes the exact vendored admission module.
Three regressions failed with the original enqueue and pass with the fix:
repeated failures across connections, duplicate admission at capacity, and
10,000 distinct candidates with bounded length/capacity and FIFO eviction.
Transport integration tests continue using real endpoints and encryption.

Checks on Linux in nix develop:
- cargo fmt --all -- --check
- cargo clippy --locked --workspace --all-targets -- -D warnings
- cargo test --locked --workspace --all-targets, with only the inherited
  TSUNAGI_CONTROL_SOCKET removed from the test environment
- git diff --cached --check

Initial full-suite runs failed six DNS readiness checks because the inherited
system socket path overrode their temporary state directories. Clearing that
environment variable resolves those failures without changing application code.
Root/network-dependent ignored tests and other operating systems were not run.
2026-10-14 23:28:53 +01:00

1.6 KiB

Developing iroh

Structured events

The library uses tracing both for logging and for structured events. Events differ from normal logging by convention:

  • The target is prefixed with iroh::_events::, with ::-separated names.
  • There is no message; the unique target indicates the meaning.
  • The fields carry exclusively structured data.
  • The Level is always DEBUG.

This lets automated tooling process events through custom subscribers while still producing distinct output under the default tracing formatters, and makes them unlikely to conflict with real modules.

An application can subscribe to the iroh::_events target separately. With the default file logging it is also easy to grep for all events:

rg 'events::[a-z_\-:]+' path/to/iroh/logs/iroh.YYYY-MM-DD-NN.log

When adding events, aim for a high signal-to-noise ratio and design them to be extracted automatically. To keep them distinct from normal logging, write them with the event!() macro:

event!(
    target: "iroh::_events::subject",
    Level::DEBUG,
    field = value,
);

Building documentation

Building the documentation is only supported with --all-features. To also document the cargo features required for certain APIs, pass the iroh_docsrs cfg to rustdoc, which requires nightly Rust:

RUSTDOCFLAGS="--cfg iroh_docsrs" cargo +nightly doc --workspace --no-deps --all-features