{"answer":"Review complete. Findings, all tied to lines in the changed files:\n\n🔴 `bug` services/proxy/src/metrics.rs:94: `values()` returns `sweep_bytes_reclaimed` and `sweep_blobs_removed` in the opposite order to `COUNTERS` (metrics.rs:51-57), so `render()`'s zip publishes the blob count under `cairn_proxy_sweep_bytes_reclaimed_total` and the byte count under `cairn_proxy_sweep_blobs_removed_total`. operations.md tells operators to alert on the bytes counter specifically, so the alert reads blob counts (e.g. 12 blobs) as bytes reclaimed.\n\n🟠 `bug` services/proxy/src/sweep.rs:232: `clear_partials` unlinks every file in `incoming/` with no age check, but that is where `BlobWriter` (store.rs:201-206) keeps the temp file of a fetch currently in progress. A 200 MiB download spanning a sweep loses its file mid-write; `commit`'s rename then fails on a path that no longer exists and the whole fetch errors after all bytes were transferred. Every sweep interval kills every in-flight download.\n\n🟠 `bug` services/proxy/src/sweep.rs:140: `forget(&index, &gone)` runs unconditionally, including for a dry run, so `?dry_run=true` — documented in admin.rs:58-60 as reporting what a sweep \"would reclaim without removing anything\" — still deletes the index entries for every digest it would have removed. The dry run is a write, and each dry run forces a refetch (and re-link) of every blob it merely reported on.\n\n🟠 `bug` services/proxy/src/routes/admin.rs:76: the on-demand route calls `sweeper.sweep(dry_run)` directly instead of `sweeper.run().await`, bypassing the `running` mutex (sweep.rs:82-85) that exists precisely so two sweeps never interleave. A manual sweep concurrent with the background one makes both compute removals from a total the other is already shrinking, over-evicting past the ceiling and double-counting bytes in the metrics.\n\n🟠 `bug` services/proxy/src/routes/admin.rs:76: the synchronous directory walk and unlinks (sweep.rs:90-149) run inline on a tokio worker thread; on a store with tens of thousands of blobs the module's own estimate (sweep.rs:14-17) this blocks a runtime worker for minutes while serving requests, and the route is deliberately exempted from the `TimeoutLayer` (routes/mod.rs:122-130) so nothing bounds it. It belongs in `run()` under `spawn_blocking` (or the lock held across a blocking task).\n\n🟡 `bug` services/proxy/src/sweep.rs:119: a blob committed by an in-flight fetch between the `referenced()` snapshot (sweep.rs:92) and the unlink loop is absent from the index map and is deleted as unreachable, even though its index entry is written moments later — so `forget` (sweep.rs:140) then deletes that fresh entry too. On a long sweep of a busy store this evicts just-fetched packages, defeating the `CAIRN_CACHE_MIN_AGE` grace the docs promise.\n\n🟡 `bug` services/proxy/src/sweep.rs:134: when `fs::remove_file` fails (sweep.rs:126-131), the candidate is still counted: `remaining` is reduced, `bytes` and `removed` incremented, and its digest pushed to `gone`. A blob that was already gone via a purge gets reported as reclaimed bytes the store never gave up, and `remaining` then under-counts the true store size, letting a sweep stop while the store is still over its ceiling.\n\n🟡 `bug` services/proxy/src/sweep.rs:164: `fs::metadata` follows symlinks, so a symlinked blob is counted at its target's size, contradicting the comment at sweep.rs:160-163 which claims links are counted at the link's own size (`fs::symlink_metadata` would be needed for that). A store assembled with hard/sym links is measured against the wrong total for the ceiling.\n\n🔵 `bug` services/proxy/src/config.rs:131: `CAIRN_SWEEP_INTERVAL` is validated for zero but `CAIRN_CACHE_MIN_AGE` is not, so `CAIRN_CACHE_MIN_AGE=0` silently disables the grace period that operations.md presents as protecting a package between pipeline jobs.","auth":{"mode":"api_key"},"effort":"high","elapsed_secs":115.732,"error":null,"error_kind":null,"instructions":[],"model":"z-ai/glm-5.3-flash","ok":true,"sandbox":{"backend":"macOS Seatbelt","denied_read_roots":["/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/subjects"],"environment":["HOME","LANG","LC_ALL","PATH","TERM","TMPDIR"],"mode":"read-only","network":"denied","protected_write_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-A678Sb/.git","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-A678Sb/.afi","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-A678Sb/.agents","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-A678Sb/.codex","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-A678Sb/AGENTS.md","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-A678Sb/CLAUDE.md"],"readable_paths":["/"],"readable_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-A678Sb","/bin","/sbin","/usr/bin","/usr/sbin","/usr/lib","/usr/libexec","/usr/share","/System/Library","/Library/Apple","/Library/Filesystems/NetFSPlugins","/Library/Preferences","/private/etc","/private/var/db/timezone","/private/var/db/DarwinDirectory/local/recordStore.data","/private/var/select/developer_dir","/private/var/select/sh","/opt/homebrew/bin","/opt/homebrew/Cellar","/opt/homebrew/etc/gitconfig","/opt/homebrew/lib","/opt/homebrew/opt","/usr/local/bin","/Applications/Xcode.app/Contents/Developer","/Applications/Xcode.app/Contents","/Users/bart.smykla@konghq.com/.local/bin/afi"],"writable_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/afi-sandbox-YbT8PL"]},"schema_version":1,"source":"openrouter","sources":[{"auth":{"mode":"api_key"},"source":"openrouter","usage":{"cache_read_tokens":64512,"cache_write_tokens":0,"cost_usd":0.014403,"estimated_tokens":0,"input_tokens":39997,"output_tokens":823,"reasoning_tokens":12659,"requests":5,"total_tokens":117991}}],"system_prompt":{"file":null,"mode":"builtin"},"tools":["read_file","write_file","edit_file","list_dir","search_files","glob_files","run_bash","wait_background"],"usage":{"cache_read_tokens":64512,"cache_write_tokens":0,"cost_usd":0.014403,"estimated_tokens":0,"input_tokens":39997,"output_tokens":823,"reasoning_tokens":12659,"refused_by_approval":0,"refused_by_policy":0,"refused_tool_calls":0,"requests":5,"total_tokens":117991}}