fix(server): worktree cleanup no longer runs sweeps back to back

[fireboltdude1357]

Problem

Worktree cleanup can run full sweeps back to back on a busy server. Every thread.deleted and provider-session.updated event queues another automatic sweep, and the worker never merges them, even though most session updates (running to ready, for example) can't free a worktree. Each eligible worktree also re-reads the full active and archived thread snapshot under its lease. Since #17911 that recheck runs twice, before and after measuring the worktree's size, so one sweep makes up to 2 + 4N snapshot reads for N eligible worktrees.

On a server with a 33 GB database and about 20 agents running, four sweeps of 325 to 399 s ran with no gap between them. Their 67 readThreads calls took 7 s at the median, and the event loop stalled for 170 s in 24 minutes. Clients disconnected during the stalls. Details are in #17479.

#17563 (reports, skip reasons, a manual run RPC) and #17911 (skip early, before the status and size walks) reworked this file but kept both behaviors: per-event worker.enqueue(undefined) with no status filter, and readThreads() inside the lease.

Change

• At most one automatic sweep waits. The hourly schedule, settings changes and domain events all go through requestSweep. A request made while an automatic sweep is waiting joins it, because that sweep hasn't read settings or threads yet. A request made while one is running queues the next one. Manual runs from fix(storage): make worktree cleanup work and show why it skipped #17563 keep their own completion and their own sweep and report, as before, so a manual run never waits on or shares an automatic one.
• Only session updates that reach "stopped" or "error" request a sweep. thread.deleted still does. Both stay gated on worktreeOnDelete.
• Read the snapshot once per sweep. perf(server): storage cleanup no longer runs a full status or size walk for worktrees it keeps #17911's blockedSinceCheck runs under each worktree's lease after the eligibility Git calls, then again after size measurement. It now reads the project list, the new ProjectionStore.getThreadWorktreePaths() (one query on the threads table: thread id and worktree path for every non-deleted thread), getThreadShell for the candidate, and the existing live-session query. A turn that starts, a session that resumes, or a new thread on the same path still cancels the removal if it commits before the recheck. perf(server): storage cleanup no longer runs a full status or size walk for worktrees it keeps #17911's ordering and early skips are unchanged, and these skips report the same reasons as before ("Thread activity or shared worktree changed since check", and so on). The path check includes archived threads, so it is at least as strict as the snapshot it replaces. Run read-only against a real database with 3,765 live threads, that query took 13 ms. A full snapshot read takes 7 s there.

#15208 (draft, settled-worktree retention) also merges sweep requests as a side change. This PR is a focused fix for the same trigger, and #15208 can drop its version when it rebases.

Two things I noticed but left alone:

• readThreads reads getShellSnapshot({ location: "archive" }) and keeps only its threads, which are always empty for that location. So archived threads never become cleanup candidates. That's a separate behavior question.
• The cleanup's live-session query treats "error" sessions as live, so an "error" update triggers a sweep that won't remove that session's own worktree. I kept the trigger because the rest of orchestration treats "error" as ended.

Scope and approval

Fixes #17479. I filed that issue alongside this PR, so it hasn't been triaged yet.

The fix doesn't change what cleanup removes, when it's allowed to, or what the report says. It changes how often automatic sweeps run and how the existing under-lease recheck reads its data. The only change outside storageCleanup.ts is the read-only getThreadWorktreePaths on ProjectionStore (SQL and memory layers) that the recheck needs. No contracts, clients or settings change.

Verification

node_modules/.bin/vp test run apps/server/src/storageCleanup.sweeps.test.ts apps/server/src/storageCleanup.test.ts apps/server/src/orchestration-v2/ProjectionStore.test.ts apps/server/src/orchestration-v2/ProviderTurnControlService.test.ts
# 4 files, 96 tests passed

storageCleanup.sweeps.test.ts runs the real StorageCleanup.layer over faked Git, projections and events, with an in-memory SQLite database:

Case	main	this PR
20 "ready"/"running" session events during a sweep	21 sweeps	1 sweep
20 "stopped"/"error" session events during a sweep	21 sweeps	2 sweeps
getShellSnapshot calls in one sweep with 4 eligible worktrees (2 kept by live sessions)	14	2

Two more tests cover the recheck. A worktree is kept, with #17563's "Thread activity or shared worktree changed since check" reason, when another thread starts using its path after the snapshot, and when its thread starts a turn after the snapshot. With the new tests run against main's storageCleanup.ts, all five fail. The existing tests in storageCleanup.test.ts pass unchanged apart from two fixture methods for the new reads. That includes "keeps a worktree when its thread starts during size measurement" and "serializes concurrent requests and returns each run's report", which now exercise the new recheck and the manual-run path. A ProjectionStore test checks that getThreadWorktreePaths keeps archived threads and skips deleted ones, on both the SQL and memory layers.

Also ran tsc --noEmit -p apps/server (no errors) and vp lint on the changed files (clean).

Not checked: I haven't run this build against a large real database, so there are no production timings with the fix yet. The numbers in the problem section come from main's traces.

This change was made by Claude Opus 5.5 (claude-opus-5-5) in Claude Code running inside T3 Code.

🤖 Generated with Claude Code

[macroscopeapp]

Approvability

Verdict: Approved at 95dc421

Macroscope's review found this PR approvable — This is a bounded cleanup bug fix that reduces redundant production sweeps and database snapshot work without changing cleanup settings, contracts, or schema. The added tests cover request coalescing and the targeted recheck behavior, and the remaining production side effects stay within the existing cleanup workflow.

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📝 Walkthrough

Walkthrough

Storage cleanup coalesces automatic sweep requests and requests event-driven sweeps only for qualifying events. Before removing a worktree, it checks current path references and, for a live thread, its current shell.

Changes

Storage cleanup

Layer / File(s)	Summary
Recheck worktree eligibility apps/server/src/orchestration-v2/ProjectionStore.ts, apps/server/src/orchestration-v2/ProjectionStore.test.ts, apps/server/src/storageCleanup.ts, apps/server/src/storageCleanup.sweeps.test.ts, apps/server/src/storageCleanup.test.ts, apps/server/src/orchestration-v2/ProviderTurnControlService.test.ts	ProjectionStoreV2 returns paths for non-deleted threads with worktree paths, including archived threads. Cleanup checks current path references and, for a matching live thread, verifies that the current shell remains idle with unchanged activity time. Tests cover path lookup and worktree rechecks.
Coalesce sweep requests apps/server/src/storageCleanup.ts, apps/server/src/storageCleanup.sweeps.test.ts	Scheduled, settings-change, and qualifying event requests use the shared automatic-request path. Tests verify that ready/running session updates do not schedule another sweep, while stopped/error updates during a sweep result in one additional sweep.

Priority: ⬆️ High

Estimated code review effort: 3 (Moderate) | ~25 minutes

Change: Bug fix · Severity of issue fixed: High

Sequence Diagram(s)

sequenceDiagram
  participant CleanupEvents
  participant StorageCleanup
  participant DrainableWorker
  CleanupEvents->>StorageCleanup: Request automatic sweep
  StorageCleanup->>DrainableWorker: Enqueue if no automatic sweep is queued
  CleanupEvents->>StorageCleanup: Request another sweep while one is queued
  StorageCleanup->>DrainableWorker: Keep at most one queued automatic sweep

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Suggested reviewers: juliusmarminge

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Merge Risk | 🟡 Moderate · up to 2d9c3

Merge Risk: 🟡 Moderate · up to 2d9c3

Large databases may still incur slow cleanup sweeps because each eligible worktree triggers full path lookups. The repeated work remains a material merge-readiness concern.

Security Architecture Review

Security architecture risk: 🔵 Low · up to 2d9c3

The change reduces redundant cleanup work without demonstrating broader deletion authority. Existing removal safeguards remain in place. Concurrent ownership changes and production-scale database costs are not fully verified, so some uncertainty remains.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The affected destructive outcome remains removal of policy-eligible managed worktrees using the server's existing Git authority. The inspected changes do not establish a new deletion entrypoint or increased privilege; automatic event amplification is reduced.

Trust Boundaries and Controls

• observed — The workspace lease covers each candidate's checks through removal and releases through finalization. It is an in-process, path-keyed semaphore, not a database-wide or cross-process ownership lock. Live-reference checks and deletion are not one atomic operation in either compared revision.
• inferred — Separate path and shell reads merit concurrency scrutiny, but a path reassignment alone does not establish newly unsafe removal of the old path. A new reference arriving after the ownership observation was also possible at the base. Complete serialization coverage for ownership writers remains unverified, rather than a demonstrated PR-introduced vulnerability.

Resilience and Maintainability Implications

• observed — Candidate failures produce failed report entries, while successful removal is recorded after Git removal succeeds. Worker finalization decrements outstanding work on failure or interruption, and later queued jobs can continue after an individual item fails.

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Pre-merge checks | 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check		The title clearly and concisely describes the main change: preventing back-to-back worktree cleanup sweeps on the server.
Description check		The description covers the required Problem, Change, Scope and approval, and Verification sections. It explains the behavior change, links the related issue, reports focused test and type-check result…
Linked Issues check		Issue #17479 requires at most one additional automatic sweep, requests only for worktree-freeing session updates, and a fixed number of snapshot reads per sweep. requestSweep coalesces queued automa…
Out of Scope Changes check		The changes stay within issue #17479. getThreadWorktreePaths is a read-only ProjectionStore method required by the cleanup recheck. Its SQL and memory implementations and tests support the cleanup o…

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Inline comments:
Review comments at @apps/server/src/storageCleanup.ts:
- Around line 493-494: Update the storage-cleanup flow around
getThreadWorktreePaths to pass worktreePath into the projection-store method and
apply the candidate-path filter in its SQL query, rather than loading all paths
and filtering in memory for each eligible worktree.

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[bompus]

A measured data point for #17479 on a build that does not have this fix yet. I have not run #17480 itself.

Install: Linux (WSL2), 0.0.46-nightly.20261011.2955, worktreeOnDelete on, about 7 sessions streaming. statev2.sqlite is 14.2 GB with 1,310 thread rows. The build predates #17911, so each sweep still calls statusDetailsLocal.

From server.trace.ndjson over 25 minutes:

• StorageCleanup.sweep ran 37 times with no gap, at 34 to 58 s each.
• provider-session.updated and thread.deleted events arrived 184 times in 83 minutes, one per 27 s. Each one enqueues a sweep, and a sweep takes longer than that, so the queue only grows.
• A sweep makes about 196 runGitCommand calls and about 10 readThreads calls at roughly 320 ms each.

The sweep costs more than its Git commands and SQL:

• Spawn cost. A 30 s perf sample of the server's main thread put 13.9% of the process's samples under ProcessWrap::Spawn, nearly all in clone and dup_mmap. libuv forks the roughly 1 GB server process for every git child. About 4.8 clones per second came from the main thread in a 20 s count, though that count is by thread name, so it may include other node processes.
• Temp files. The shell snapshot and getThreadsWithPullRequests both ORDER BY updated_at over rows that carry payload_json. Thread payloads total 15 MB here because of long linked-PR lists. That is far above SQLite's default 2 MB sort buffer, so each call spills 13 to 15 MB to an unlinked etilqs_* temp file. A 39 s kernel write count attributed 4.4 MB/s of the server's 5.9 MB/s write_bytes to these files. PRAGMA cache_size=-32768 or temp_store=MEMORY brought both calls to 0 bytes of temp writes when I ran them against a copy of this database.

Replacing the per-candidate snapshot with one narrow query, as #17480 does, should remove most of the temp-file volume, but I did not measure that.