{"answer":"Reviewing the diff against the checked-out code. The sweep feature touches `sweep.rs`, `admin.rs`, `metrics.rs`, `main.rs`, `config.rs`, and the router; I read all of them plus `store.rs` (the layout and writer lifecycle the sweep depends on). Findings:\n\n🟠 `bug` services/proxy/src/metrics.rs:94: `values()` returns `sweep_bytes_reclaimed` before `sweep_blobs_removed`, but `COUNTERS` (lines 51-57) lists `cairn_proxy_sweep_blobs_removed_total` first — `render()` zips them in order, so every scrape publishes the byte count under the blobs-removed name and vice versa; any alert or dashboard built on the documented counter names reads the wrong quantity.\n\n🟠 `bug` services/proxy/src/sweep.rs:232: `clear_partials` unlinks every file in `incoming` with no age or ownership check, but `BlobStore::writer` (store.rs:171-180) puts the temp file of every *in-flight* fetch there — a sweep concurrent with any active download unlinks its temp, so the fetch's `commit` rename fails (store.rs:259) and the download errors out; the \"a file in `incoming` is a fetch that is not coming back\" premise is false for live writers, and `CAIRN_CACHE_MIN_AGE` is not honoured here either.\n\n🟠 `bug` services/proxy/src/sweep.rs:140: `forget(&index, &gone)` runs unconditionally, including on a dry run — nothing in `sweep` removes blobs during a dry run, yet `gone` holds every candidate that *would* be removed, so `?dry_run=true` (documented as reporting \"without removing anything\") actually deletes the index entries naming those blobs, turning a read-only query into a destructive one.\n\n🟠 `bug` services/proxy/src/routes/admin.rs:76: the on-demand route calls `app.sweeper.sweep(dry_run)` directly, which does not take the `running` mutex (sweep.rs:83) that exists precisely so two sweeps cannot each compute from a total the other is changing — a `POST /v1/admin/cache/sweep` racing the interval sweep (or a second POST) makes both evict against the same `held`, driving the store far below the ceiling and double-counting `removed`/`bytes` in the metrics.\n\n🟡 `bug` services/proxy/src/sweep.rs:137: when `fs::remove_file` fails (line 126), the blob is still pushed to `gone` and counted in `removed`/`bytes`, so `forget` deletes index entries pointing at a blob that still exists (next resolve misses and refetches) and the sweep metrics overstate what was reclaimed.\n\n🟡 `bug` services/proxy/src/main.rs:108: the doc comment claims \"the first tick is one interval away\", but `tokio::time::interval`'s first tick completes immediately, so a sweep runs at startup — harmless on an empty store, but on a restart with a populated store and clients already hitting it, it makes the in-flight-partial deletion and the commit→link eviction window in `sweep.rs` fire on the very first requests rather than one interval in.\n\n🟡 `bug` services/proxy/src/routes/admin.rs:76: `sweep()` is fully synchronous (the module doc at sweep.rs:14-18 commits to stdlib `fs`), and the handler runs it inline on a tokio worker thread — a walk over tens of thousands of directories plus a read of every index entry can block a worker for minutes, starving the very cache serves the untimed route exists to protect; it needs `spawn_blocking`.\n\n🔵 `bug` services/proxy/src/sweep.rs:168: `collect` recurses through symlinked directories (`fs::metadata` follows symlinks, `is_dir()` is true for a dir symlink) with no cycle check, despite the comment at lines 160-163 explicitly contemplating a store populated by links — a symlink loop under `blobs/` recurses until the stack overflows, taking down the process.","auth":{"mode":"api_key"},"effort":"high","elapsed_secs":102.799,"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-JmgOFw/.git","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-JmgOFw/.afi","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-JmgOFw/.agents","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-JmgOFw/.codex","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-JmgOFw/AGENTS.md","/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-JmgOFw/CLAUDE.md"],"readable_paths":["/"],"readable_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/benchee-agent-JmgOFw","/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-MvgeHJ"]},"schema_version":1,"source":"openrouter","sources":[{"auth":{"mode":"api_key"},"source":"openrouter","usage":{"cache_read_tokens":48384,"cache_write_tokens":0,"cost_usd":0.013925,"estimated_tokens":0,"input_tokens":41480,"output_tokens":487,"reasoning_tokens":12405,"requests":4,"total_tokens":102756}}],"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":48384,"cache_write_tokens":0,"cost_usd":0.013925,"estimated_tokens":0,"input_tokens":41480,"output_tokens":487,"reasoning_tokens":12405,"refused_by_approval":0,"refused_by_policy":0,"refused_tool_calls":0,"requests":4,"total_tokens":102756}}