fix(pegboard): isolate runner config dc lookup failures

[NathanFlurry]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[NathanFlurry]

• fix(pegboard): isolate runner config dc lookup failures #4625 : 2 dependent PRs (#4626 , #4630 ) 👈 (View in Graphite)
• docs(pegboard): note runner config upsert split write risk #4624
• fix(pegboard): unpack global runner config keys correctly #4623
• fix(pegboard-gateway): enforce tunnel message state #4622
• fix(pegboard-runner): clear terminal tunnel routes #4621
• fix(pegboard): skip protocol version keys in runner pool backfill #4620
• fix(pegboard): create missing normal runner configs #4619
• fix(epoxy): reuse cached optimistic value #4618
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[claude]

PR Review: fix(pegboard) - isolate runner config dc lookup failures

Summary: Focused change converting list_runner_config_enabled_dcs_inner from fail-fast (propagating errors) to fault-tolerant behavior (log warning and continue). Appropriate for a distributed system where individual DC lookups may transiently fail.

Positive Observations

• Fault isolation is correct. A single unreachable DC should not abort the entire lookup; the new behavior degrades gracefully.
• Structured logging follows project conventions. The warn! log uses structured fields (?err, namespace_id, runner_name, dc_label) and a lowercase message.
• Clean import cleanup. TryStreamExt is correctly removed since try_filter_map/try_collect are replaced with non-Try equivalents.
• Stream pipeline is correct. filter_map(std::future::ready) is the right replacement when futures return Option instead of Result<Option>.

Concerns

1. Silent failure semantics: When a DC lookup fails, the DC is excluded from results — indistinguishable from a DC with no runner config. If this function influences where runners are scheduled, transient storage errors could silently prevent runners from being deployed to otherwise-healthy DCs. Consider adding a comment near the Err arm explaining why exclusion-on-failure is the intended behavior, so future readers understand it is deliberate.

2. No test coverage for the error path: A test verifying that one failing DC does not abort the overall result (and that successful DCs are still returned) would harden this against regressions.

Minor

• buffer_unordered(512) predates this change, but 512 concurrent KV operations is quite high. Not a blocker, but worth a follow-up.

Verdict

The change is correct and an improvement over the fail-fast behavior. Main follow-ups: test coverage for the error path, and a comment explaining the exclusion-on-failure semantics.

[github-actions]

Preview packages published to npm

Install with:

npm install rivetkit@pr-4625

All packages published as 0.0.0-pr.4625.34285f4 with tag pr-4625.

Engine binary is shipped via @rivetkit/engine-cli on linux-x64-musl, linux-arm64-musl, darwin-x64, and darwin-arm64. Windows users should use the release installer or set RIVET_ENGINE_BINARY.

Docker images:

docker pull rivetdev/engine:slim-34285f4
docker pull rivetdev/engine:full-34285f4

Individual packages

npm install rivetkit@pr-4625
npm install @rivetkit/react@pr-4625
npm install @rivetkit/rivetkit-native@pr-4625
npm install @rivetkit/sqlite-wasm@pr-4625
npm install @rivetkit/workflow-engine@pr-4625

[MasterPtato]

Merge activity

• Apr 13, 8:40 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Apr 13, 8:58 PM UTC: Graphite rebased this pull request as part of a merge.
• Apr 13, 8:59 PM UTC: @MasterPtato merged this pull request with Graphite.