fix(watch): stop reporting a routine watch reconnect as a failure - #363
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The API server ends every watch on its own randomized timeout. The stream
reconnects from its cursor in about two seconds, `writeLost` stays false, and
render fidelity never moves — the protocol working exactly as designed.
That ending was graded as a failure. `runTargetWatch` marked the cell
Blocked/WatchError on any non-nil error, `streamReasonIsStalled` counts
WatchError as stalled, so Ready went False, `recordReadyTransition` emitted a
Warning, and the GitTarget dropped to the 10s requeue cadence — roughly every
forty minutes, per watched type, on a completely healthy cluster. Reported from
a cluster where 100% of the Warning events in the namespace were this, which is
the actual cost: a genuinely blocked stream arrives as the sixty-fifth
identical-looking Warning and nobody picks it out.
Session-end classification now happens in one function. A session ENDING says
only that it ended; whether anything is wrong is the next open's answer, and
every open-failure path already marks the cell Blocked one backoff later. So a
clean end publishes nothing at all.
It deliberately does not report a distinct non-stalled reason for the reconnect
either, which is the other shape this could take. Any state other than Streaming
flips StreamsRunning and so flips Ready, which would leave
`kubectl wait --for=condition=Ready` and every CI gate built on it racing a
healthy cluster every forty minutes. Trading a cosmetic Warning for a flaky
readiness gate is a worse deal than the one being fixed.
Two further instances of the same misclassification go with it:
- `watch_sessions_ended_total` counted the routine reconnect as
`reason="error"`. It is now `closed`, for the reason the mid-stream 410 was
split out as `expired`: `error` is what an operator reads as "something is
actually broken". It is also now the only place a reconnect is visible,
which is what makes a hot flap detectable — the accepted cost of publishing
no stream state, and `docs/interpreting-metrics.md` ships the query.
- A 410 observed inside a cold-started session propagated to the generic arm
and marked Blocked/WatchError, while the identical expiry on the resume path
marked Replaying/ExpiredResourceVersion. Same 410, two gradings, decided by
which session happened to see it. Both now read as Replaying.
Separately, and on the same theme: Event severity is graded by `Stalled` rather
than by "Ready is not True". Those are different questions. The readiness
accumulator has already answered this one — readinessProgressing is kstatus
InProgress, readinessStalled is kstatus Failed — and publishes it as `Stalled`,
so reading it back cannot drift from the trio. A controller restart, where every
stream is legitimately replaying, no longer emits a Warning per object for the
protocol working. An absent Stalled keeps Warning, so a future caller that
publishes Ready without the trio stays loud.
Both observable changes are documented in `docs/UPGRADING.md`, including what to
do about an Event pipeline that routes on `type=Warning`.
Also carries an unrelated edit to the README's overview diagram that was already
in the working tree: it gains a "ClusterProvider (optional)" box, and the canvas
grows to fit it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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📝 WalkthroughWalkthroughThe change updates watch session classification, prevents routine reconnects from publishing failure states, grades expired resources as replaying, and bases Ready transition event severity on the Stalled condition. Documentation and the coverage baseline reflect these changes. ChangesWatch and status behavior
Priority: ➖ Normal Estimated code review effort: 3 (Moderate) | ~20 minutes Change: Bug fix Sequence Diagram(s)sequenceDiagram
participant TargetWatch
participant SessionEndGrader
participant StreamState
TargetWatch->>SessionEndGrader: classify session-end error
SessionEndGrader-->>TargetWatch: clean close, replay, or blocked result
TargetWatch->>StreamState: publish only replay or blocked result
Merge Risk: 🔵 Low · up to Alert rules copied from the upgrade guidance could miss in-progress Ready=Unknown transitions. Clarify the predicate before merging. 🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
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In `@docs/UPGRADING.md`:
- Line 46: Update the upgrade documentation’s alerting guidance to use the
documented Ready predicate for every not-ready transition, including
Ready=Unknown; state the condition as Ready != True rather than only
Ready=False.
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The upgrade note told operators who want the old Warning breadth to route on `Ready` going False. That misses a state the controller genuinely publishes: a progressing gate that has not been ESTABLISHED reports Ready=Unknown, not False — gittarget_controller.go does exactly this when a source cluster has not yet reported reachability, and readiness.progressing takes the status precisely so the two stay distinguishable. So the advice as written would have left a gap in the alert it was recommending, on the very transitions this change moves from Warning to Normal. kstatus treats False and Unknown alike as InProgress; the predicate is `Ready != True`. The rule in the conditions guide gains the same qualification, since it is the document the upgrade note is derived from. Reported by CodeRabbit on #363. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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Reported from operating 0.44.0 against a demo cluster: a steady trickle of
Warningevents, roughly one every forty minutes, rotating between the watched CRDs.Nothing was wrong. The whole life of one:
Two seconds, self-healing,
writeLost: falsethroughout,render: True/RenderMatchesLiveon both sides. This is the kube-apiserver closing a watch on its normal randomized timeout — the thing every watch client is built to expect — and the controller reconnecting from its cursor exactly as designed.On that cluster 100% of the
Warningevents in the namespace were this, which is the actual cost. A genuinely blocked stream arrives as the sixty-fifth identical-looking Warning and nobody picks it out.What produced it
targetWatchReplayAndStreamreturns the package's own sentinelerrTargetWatchClosed, and the reconnect loop marked the stream on any non-nil error. From there it was mechanical:streamReasonIsStalledcountsWatchErroras stalled →Readygoes False →recordReadyTransitionemits aWarning→ the GitTarget drops to the 10s requeue cadence for a cycle.The defect is not one missing
errors.Is. It is that session-end classification was spread across the call stack instead of being decided once, which is why the same misclassification showed up in two more places (below).The fix
A session ending says only that it ended. Whether anything is wrong is the next
open's answer — and every open-failure path already marks the cellBlocked/WatchErrorone backoff later. So a clean end now publishes nothing at all, and the grading lives in one pure function:errTargetWatchClosedBlocked/WatchErrorerrTargetWatchExpiredReplayingExpiredResourceVersionBlocked/WatchErrorBlockedWatchErrorWhy not a distinct
ReconnectingreasonThat was the other shape on the table, and it's the more tempting one — the stream genuinely is momentarily down, so reporting it looks more honest.
It has a cost that isn't visible from outside the controller: any state other than
StreamingflipsStreamsRunning, which flipsReady. That would leavekubectl wait --for=condition=Readyand every CI gate built on it racing a healthy cluster every forty minutes, per watched type. Trading a cosmetic Warning for a flaky readiness gate is a worse deal than the one being fixed.Accepted risk, stated plainly
A hot flap —
opensucceeds, the session dies immediately, forever — now reads as healthy, because the stream never leavesStreaming. That is what the metric change below is for, anddocs/interpreting-metrics.mdships the query. This is a deliberate trade, not an oversight.Two more instances of the same misclassification
watch_sessions_ended_totalcounted the routine reconnect asreason="error". Nowclosed— for exactly the reason the mid-stream 410 was split out asexpired, which this codebase already argued against itself:A 410 graded differently depending on which session caught it. Expiry on the resume path marked
Replaying/ExpiredResourceVersion; the identical expiry inside a cold-started session's pump fell through to the generic arm and markedBlocked/WatchError. Same 410, two gradings, decided by nothing but which session observed it. Both now read asReplaying.Event severity is graded by
StalledSame theme, wider scope, and reviewable on its own — it is the last commit-worth of this change and can be dropped if you'd rather it shipped separately.
recordReadyTransitionpickedWarningfor anything that was notReady=True. But "is Ready false" and "does a human need to do something" are different questions, and the readiness accumulator has already answered the second one:readinessProgressingis kstatusInProgress,readinessStalledis kstatusFailed. That verdict is published asStalled, so reading it back cannot drift from the trio.Before this, a controller restart — where every stream is legitimately replaying — emitted a
Warningper object for the protocol working. An absentStalledkeepsWarning, so a future caller that publishesReadywithout the trio stays loud rather than being silently downgraded.Not changed
Per the report, and agreed: the reconnect behaviour, the 2s backoff, and the cursor resume all do the right thing — the two-second recovery is why this was a cosmetic complaint rather than an outage. No event suppression either; Kubernetes' own aggregation already handles repeats, and it is what made the occurrence counts measurable in the first place.
Upgrade impact
Two observable surfaces move, both covered in
docs/UPGRADING.md:watch_sessions_ended_totalgainsreason="closed". An alert onreason="error"gets quieter and more accurate.Ready=Falsetransitions on all five reconciled kinds are nowNormal. An Event pipeline routing ontype=Warningstops seeing startup replays and dependency waits — that is the intent. Alerting that wants the old breadth should route on theReadycondition itself, which is the more durable signal anyway.Testing
targetStreamStateForSessionEndtable, including a wrapped sentinel.TestRunTargetWatch_CleanCloseIsSilentAndTheNextOpenReportsasserts both halves of the design argument: the clean close publishes nothing, and the next open's failure is what marks the stream blocked. Neither is safe alone — suppressing the clean end would hide a genuine outage if the open did not speak up. Verified this test fails against the old behaviour before keeping it.sessionEndReasoncoversclosed, a wrappedclosed, and teardown still outranking the close it causes.recordReadyTransitionseverity in both directions — there was none before.Full gate green:
fmt/generate/manifests/vet/lint/test(coverage 77.9% → 78.0%) /test-e2e.Unrelated change carried along
docs/images/overview.excalidraw.svggains a "ClusterProvider (optional)" box. It was already edited in the working tree and is included deliberately rather than stranded.🤖 Generated with Claude Code
Summary by CodeRabbit
Bug Fixes
closed) from genuine errors.Documentation