[t3dotgg]

When a remote host got CPU-starved (leftbook at load 219 on 18 cores from a benchmark), its T3 server froze for 10 to 20s at a time. The only thing the user saw was a "Some requests are slow" toast for server.reportClientActivity · 33104658-322c-…. That is a background heartbeat nobody waits on, shown with an environment UUID. The disconnect reason was "leftbook stopped responding. Your DNS or firewall may be blocking T3 Connect.", even though the socket had been working for 90s.

Now:

• The slow-request toast skips server.reportClientActivity and names the environment ("… · leftbook"), not its id.
• When an open connection goes quiet, the reason reads "leftbook stopped responding for 15s. It may be overloaded, asleep, or off the network." The DNS/firewall hint stays only for sockets that never open.
• The transport-error matcher still treats the new text as a connection error, so thread errors stay clean.

A follow-up stacked PR has the server report the real cause ("leftbook froze for 12s. Its CPU is overloaded").

Reviewed with sol-loop: 1 round with GPT-6.1 Sol. Sol verdict: approved

Created with Claude Opus 5.5 in Claude Code.

🤖 Generated with Claude Code

[macroscopeapp]

Approvability

Verdict: Approved at b17c252

Macroscope's review found this PR approvable — This is a focused client diagnostics fix that suppresses misleading background-heartbeat warnings, uses environment labels, and distinguishes an unresponsive open connection from an initial network failure. Connection timing and transport behavior remain unchanged, and the affected paths have focused test coverage.

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[coderabbitai]

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ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Path: .coderabbit.config.ts
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• Run ID: 8e2bd474-7c19-48c7-bf86-4551c1b93232

📥 Commits

Reviewing files that changed from the base of the PR and between 72bdf1e and b17c252.

📒 Files selected for processing: 10

• apps/web/src/connection/platform.ts
• apps/web/src/rpc/requestLatencyState.test.ts
• apps/web/src/rpc/requestLatencyState.ts
• packages/client-runtime/src/errors/network.ts
• packages/client-runtime/src/errors/transport.test.ts
• packages/client-runtime/src/errors/transport.ts
• packages/client-runtime/src/rpc/client.test.ts
• packages/client-runtime/src/rpc/client.ts
• packages/client-runtime/src/rpc/session.test.ts
• packages/client-runtime/src/rpc/session.ts

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📝 Walkthrough

RPC tracking now uses environment display labels, and slow-ack tracking excludes client-activity requests. Connection timeout messages distinguish established connections that stop responding from connections that fail to open.

Changes: RPC Tracking and Connection Diagnostics

Layer / File(s)	Summary
Connection timeout diagnostics packages/client-runtime/src/errors/network.ts, packages/client-runtime/src/errors/transport.ts, packages/client-runtime/src/errors/transport.test.ts, packages/client-runtime/src/rpc/session.ts, packages/client-runtime/src/rpc/session.test.ts	Established connections that stop responding report the timeout duration and an unresponsive-host hint. Initial connection failures retain the network hint. Tests cover direct and relay sessions and transport error matching.
Request observation labels packages/client-runtime/src/rpc/client.ts, packages/client-runtime/src/rpc/client.test.ts, apps/web/src/connection/platform.ts	Request observations include the target environment label. Tracked request descriptions use the environment label instead of the environment ID.
Background RPC acknowledgment exclusions apps/web/src/rpc/requestLatencyState.ts, apps/web/src/rpc/requestLatencyState.test.ts	Slow-ack tracking excludes usage-summary and client-activity RPC methods. Tests cover both methods.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge, maria-rcks

Merge Risk: ⚪ Minimal · up to b17c2

No actionable merge-blocking risk was identified; the PR is mergeable with normal checks.

Pre-merge checks: 3 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Description check		The description explains the problem and the implemented changes, but it does not provide the required Scope and approval section or focused verification results. The AI review note does not replace m…	Add a Scope and approval section with the triaged issue or explicit maintainer approval, or explain why this focused bug fix qualifies for an exemption. Add a Verification section that lists the focused tests or manual checks run, their obs…

Passed checks: 3 passed

Check name	Status	Explanation
Title check		The title clearly describes the primary fix: frozen hosts no longer produce misleading slow-heartbeat or DNS-related messaging.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Description check

Explanation

The description explains the problem and the implemented changes, but it does not provide the required Scope and approval section or focused verification results. The AI review note does not replace maintainer approval or test evidence.

Resolution

Add a Scope and approval section with the triaged issue or explicit maintainer approval, or explain why this focused bug fix qualifies for an exemption. Add a Verification section that lists the focused tests or manual checks run, their observed results, and any checks that were not run. Keep the agent model and harness note if applicable.

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