Files
pezkuwi-subxt/polkadot/node/gum
Squirrel be8e626806 Set clippy lints in workspace (requires rust 1.74) (#2390)
We currently use a bit of a hack in `.cargo/config` to make sure that
clippy isn't too annoying by specifying the list of lints.

There is now a stable way to define lints for a workspace. The only down
side is that every crate seems to have to opt into this so there's a
*few* files modified in this PR.

Dependencies:

- [x] PR that upgrades CI to use rust 1.74 is merged.

---------

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
2023-12-13 15:11:07 +01:00
..
2023-09-04 12:02:32 +03:00

tracing-gum

"gum" to make tracing::{warn,info,..} and mick-jaeger stick together, to be cross referenced in grafana with zero additional loc in the source code.

Usage

See the crate docs (e.g. run cargo doc --open) for usage information!

Architecture Decision Record (ADR)

Context

For cross referencing spans and logs in grafana loki and tempo, a shared traceID or TraceIdentifier is required. All logs must be annotated with such meta information.

In most cases CandidateHash is the primary identifier of the jaeger::Span and hence the source from which the traceID is derived. For cases where it is not the primary identifier, a helper tag named traceID is added to those spans (out of scope, this is already present as a convenience measure).

Log lines on the other hand side, use warn!,info!,debug!,trace!,.. API provided by the tracing crate. Many of these, contain a candidate_hash, which is not equivalent to the traceID (256bits vs 128bits), and hence must be derived.

To achieve the cross ref, either all instances of candidate_hash could be added or this could be approached more systematically by providing a macro to automatically do so.

Related issues:

Decision

Adding approx. 2 lines per tracing line including a candidate_hash reference, to derive the TraceIdentifier from that, and printing that as part of the key-value section in the tracing::* macros. The visual overhead and friction and required diligence to keep the 100s of tracing::{warn!,info!,debug!,..} up is unreasonably high in the mid/long run. This is especially true, in the context of more people joining the team. Hence a proc-macro is introduced which abstracts this away, and does so automagically at the cost of one-more-proc-macro in the codebase.

Consequences

Minimal training/impact is required to name CandidateHash as candidate_hash when providing to any of the log macros (warn!, info!, etc.).

The crate has to be used throughout the entire codebase to work consistently, to disambiguate, the prefix gum:: is used.

Feature Parity with tracing::{warn!,..} is not desired. We want consistency more than anything. All currently used features are supported with gum as well.