usenet-indexer/REBUILD.md

Voyager 2: header-first indexer (concept)

The concept for what runs (since 2026-10-11; it started as the spec of a rebuild, then a draft for approval). Voyager 1's CONCEPT.md and its decisions D1–D42 are superseded; its domain model still holds, and its features not yet here are the phase 2 backlog below.

Branch rebuild. Phase 1 finds releases from headers and makes their NZBs. Everything learned from articles (names from yEnc headers, par2, archive listings, encryption, spots) is phase 2 and adds to what phase 1 stored; it never rewrites it. Sources: CONCEPT.md, LOG.md 2026-10-08 (13)–(14).

Status (2026-10-09)

Built on this branch (a fresh AdonisJS 7 app; phase 1 code imported from the current app by pipeline stage): coordinator (planner, NNTP pool, prefetch spool, leases, rule sets, fragment merger, settling), the node API (lease, framed stream, batches, finish/release/heartbeat), the edge worker (edge:node, --processes), the catalog and chunk store, NZBs and a name search. Measured on the workstation (4 cores, 100 Mbit, Eweka):

• Edge worker, one core: ~210–215 k headers/s on recent a.b.boneless, ~330–340 k on a 2013 a.b.ath range; ~0.7–0.8 GB peak per process. (Start: 73–103 k/s, 1.0–1.2 GB.) What's left is spread out (the per-file key ~12%, GC ~10%, zlib ~10%, the scan ~6%).
• NNTP: Eweka takes ~1.5–2 s per XOVER command; ~22–30 k lines/s per connection in chunks of 100 k when the line allows; connections don't slow each other.
• Bandwidth: compressed XOVER is ~69 B per article on recent boneless (100 k-article chunks of ~7 MB). The workstation's 100 Mbit line carries ~140–150 k articles/s, which is where its end-to-end runs now stop (10 connections 90–99% busy, ~89 Mbit/s).
• End to end at that rate (one 4-core machine): workers about half busy each; server side ~17% (coordinator) + ~8% (web) + ~3% (Postgres) of a core. (Before this round's fixes Postgres was at 32%: the merger's neighbour query read every range per file.)
• On homelab (12 cores, 1 Gbit; 2026-10-09, separate containers and database, /mnt/bulk/usenet-rebuild): 20 connections fetched ~630 k articles/s (~31 k per connection, ~3 s per 100 k chunk, ~250 Mbit/s at ~50 B per article on older boneless) and 8 worker processes indexed all of it, waiting for the spool (~366 M headers in ~12 minutes). Server side at that rate: coordinator 0.4–0.5 cores (1.3–1.7 before it stopped inflating replies to check them), web 0.3–0.45, Postgres (on the HDD) under 0.15. Worker per core there: ~195 k headers/s (boneless 2026), ~275 k (ath 2013).
• Storage: chunks 17.9–20.3 B per segment (format v2); a release ~1.1 KB.
• For the whole target (528 B overview lines): ~36 TB of compressed XOVER to download. At 50 connections (~1–1.25 M lines/s, ~0.6–0.7 Gbit/s) ~5–6 days, ~5–6 worker cores, two coordinator shards (one process handles ~60 MB/s), under a core for web and Postgres. The line is the limit below ~0.7 Gbit/s: at 1 Gbit, ~3.5 days at best.

Where workers run: total speed is set by the account's NNTP connections (~30 k articles/s each), not by worker CPU, so remote workers don't make it faster; they take CPU off homelab (at 1.25 M/s ~7 worker cores) at the cost of relaying the compressed XOVER (≤ ~0.7 Gbit/s up, homelab has 1 Gbit/s). Plan: coordinator, web, Postgres and a few workers on homelab, most workers on batcave, a few on poweredge-kantoor with edge:node --max-mbit (e.g. 50 of its 160 Mbit/s ≈ 100–125 k articles/s; the cap is shared by the node's processes).

Also built (2026-10-09): the live tail (new articles planned every 2 minutes from one LIST ACTIVE per name prefix, at priority −1: leased and fetched before history); the catalog API, Newznab (/api) and the web interface, from voyager 1 (the current build), with categories from the name; voyager 1's 29 learned garbage signatures (rules:signatures, database/data/voyager1_signatures.tsv).

Deployment (2026-10-10): Dockerfile (targets app and edge), deploy/compose.yaml (project usenet-rebuild on homelab), deploy/deploy.sh; a push to rebuild that passes CI is deployed. See deploy/README.md.

Not built yet: re-running ranges for a retracted rule (the counts and rule versions are recorded), decision f, phase 2 (inspection of the probe queue: yEnc names, encryption, archives, par2; passwords; spots).

Target

7,000 days (all of Eweka's retention, back to 2008-08) of the 1000 largest alt.binaries.* groups. Estimated: 528 B overview lines; 435 B in their main group; 140 B kept segments in ~1.25 B files and ~115 M releases after dropping garbage; 28 TB of compressed overview traffic. Throughput goal: ≥ 25 B overview lines/day (~50 connections), so ~3 weeks.

Parts

1. Coordinator (server). Plans each group's history as ranges of 2 M articles, leases them to workers, tracks progress and retries. The group list (owner rule) and the garbage signature table go with every lease. Fetches XOVER for the workers (relay: workers have no NNTP account; the gzip stream is passed on as is).

   Prefetch: the coordinator fetches the next ranges ahead of the workers, in chunks of 100 k lines and in order, into a spool on disk (~106 MB per 2 M range at ~53 B per line; on the HDD, written and read sequentially). It keeps about two ranges ahead per active lease, capped by size (default 10 GB), and fetches with all its header connections all the time, independent of how fast workers are. A lease goes to a range that is already (partly) spooled, else to the next planned one (leased ranges are fetched first); a worker reads its chunks from the spool, waiting only for chunks still being fetched. A worker gets its whole range in one streaming request (GET /ranges/:id/stream): the spooled chunks in order, waiting for those still being fetched. It still parses chunk by chunk (2 M lines are ~560 MB of text) and posts results per batch, moving the range's resume point. Chunks matter on the NNTP side: a compressed XOVER reply can't be resumed, old ranges answer slowly, and chunks of one range can be fetched in parallel. Spooled chunks are deleted when their range's results are stored, and fetched again if a range is leased again later. Order: oldest era first (2008–2018 holds 63% of the readable files on 17% of the lines), then forward. One coordinator process handles ~60 MB/s of compressed XOVER (its event loop was 16.5% busy at ~10 MB/s); beyond that, prefetching is split over processes with coordinator:run --shard=i/n (ranges with id % n = i − 1, each with its own NNTP_CONNECTIONS; only shard 1 plans, merges and settles).

2. Edge worker (node, TypeScript reusing lib/). Measured (edge:bench, 2026-10-09, after two rounds of work): ~200–215 k headers/s per core on recent a.b.boneless, ~320–340 k on a 2013 a.b.ath range, ~0.7 GB peak per process. Rust (edge/, the same RangeIndexer path over the same captures; check.ts finds every output identical, the decoded payloads included): 3.5–3.8× less CPU (boneless 2.9 vs 11.1 CPU-s per 2 M headers, ath 2.15 vs 7.5) and a third of the memory (0.20–0.24 GB). Its gains: no GC, hand-written matching instead of the regexes, mimalloc, libdeflate (half of zlib's inflate time) and SIMD line scanning. At the full target (~1.25 M/s) that is ~1.5–2 worker cores instead of ~6–7; the speed is still set by the NNTP connections. The cost: a second implementation of lib/headers, lib/release, lib/rules and the chunk format, kept identical (check.ts) for as long as both exist. Findings, how to run both and how to compare their outputs: edge/README.md. Since 2026-10-09 the Rust worker (edge-node, same crate) is the one running on homelab: ~8× less CPU per header and 20× less memory than edge:node in production. Per lease: compressed chunks of 10–50 k lines, in order → parse subjects → skip crossposts outside their owner group (of the indexed groups in the article's Xref, the one with the lowest priority number; see the group list) → group articles into files → files into releases (lib/release rules) → drop garbage (random name + dropped signature or tool) → set aside per-article random subjects and obfuscated subjects (counted only; phase 2). Returns per batch: release chunks, edge fragments, probe candidates, counters. Holds no state beyond its lease.

   Probe candidates: per release, the articles phase 2 should read, as (release key, kind, message-id, file in its chunk): the first article of the first archive volume (.part01.rar, .rar, .7z.001), of the par2 index (smallest .par2), and of a lone random-named file; for a 7z set also its last volume (the listing is in the tail). At most a few per release (~115 M releases → ~150–250 M articles), not one per file. Per- article and obfuscated subjects get none (they need every article's body).

3. Chunk store (bulk, append-only). One record per release per batch: its files' names, sizes and segment lists, compactly encoded (template codec for message-ids, zstd). Written once, never updated. A batch is stored in one transaction and only when it starts at its range's resume point, so a batch sent twice or late is refused and the catalog's sums stay right (no per-file dedup); a recovery run for a retracted rule only adds what that rule had dropped. ~3 TB.

4. Release catalog (hot, Postgres on NVMe). One row per release: key, name, poster, groups, posted_at, file count, size, segments, expected file count ([i/N]), has-par2, readable-name flag, state. Updated with aggregates once per batch (one upsert per release per batch), plus a small name index for search. ~115 M rows, ~50–100 GB.

5. Rules and recovery. What a worker skips isn't stored (message-ids are the bulk: garbage alone would be ~2.5 TB); a skipped range is read again instead (headers are cheap: ~53 B per overview line compressed).

   • Per range, per rule and signature: how many articles and files the rule dropped (garbage per (tool, group), per-article random subjects, obfuscated subjects, and crossposts per owner group). A few rows per range.
   • Rule versions: every range records the version of the rule set it ran with. Retracting or changing a rule makes the ranges where it matched stale; the coordinator leases them again for that rule only, and the worker returns just what the rule had dropped.
   • Sample: ~1% of what each rule drops (by a hash of the release key) is kept with full file details and probe candidates, so a rule can be checked, and its losses measured in phase 2, before it is retracted.

6. Probe queue. The candidates, in the catalog's database: one small row each (release, kind, message-id, chunk reference), priority by the release's state (settled first) and kind (random names before readable ones). Phase 2 takes them from here; phase 1 only fills it.

7. Fragments. Files crossing a range edge: kept by range and article number; merged when the neighbouring range is done, then written as a chunk. Never staged per segment.

8. Settling. A release is settled when the ranges covering its posting span are done and no chunk arrived for a day: completeness is computed then (expected vs found files and segments). Phase 2 picks its work from settled releases.

9. NZB and API. NZB built from a release's chunks; a minimal Newznab search (names) and get. Web UI later.

Group list

Editable at any time: an added group gets its ranges planned, a removed one no new leases. Each group gets a priority number when it is added (the first list by size, later additions after it); a crosspost belongs to the indexed group in its Xref with the lowest number. So adding a group never takes articles from groups already done, and removing one re-reads only the ranges of other groups whose counts show crossposts skipped for it (part 5). Start: the 1000 largest alt.binaries.* groups by LIST ACTIVE (~266 k ranges of 2 M articles; boneless alone 80 k).

Corpus

The grouping sweeps' dataset (2026-10-12; LOG.md 2026-10-12 (12)): the XOVER chunks of ranges marked capture, kept on the HDD in corpus/<group>/<start>-<end>/ (edge-bench's layout, range.json once complete), up to 300 GB. The prefetcher stores them as it fetches and reads them from there afterwards, so a reset re-indexes them without the news server. deploy/corpus_sweep.py marks more ranges each sweep (capture, spread over groups and eras, the top-100 groups first), replays every stored range with the deployed build's edge-bench (replay, ~seconds a range) and reports suspects and the change since the previous build (report). A rule change is judged on the whole corpus before a reset.

Phase 2

Built: the prober (2026-10-11; probe:run, LOG.md 2026-10-11 (2)). It reads the probe queue's first articles (lone, par2, archive) and stores per release whether it's passworded and its inner name, which search, the web interface and Newznab use.

Built: the par2 merge (2026-10-12; releases:merge, the merger service, LOG.md 2026-10-12 (13)). The prober stores per probed file start the MD5 of its first 16 KiB (file_hashes) and per par2 body its set's file list (par2_files, par2_sets), which holds the same hash per file whatever the file was renamed to. Every minute the merger merges the releases of one group, posted within 48 hours of a release holding the set's par2, whose files the set describes, into the one with the most files (chunks, candidates, inspections, counts; the par2's shared name when none was readable); release_merges keeps what went where. Obfuscated uploads whose files were each a release of their own (lone candidates) become one.

Backlog: voyager 1's features not in voyager 2 (CONCEPT.md decisions; voyager 1's data exported to /mnt/bulk/usenet-rebuild/v1-export/ on homelab: voyager1-tables.dump with 2.76 M spots, upload signatures, signature probes, dropped releases and groups; voyager1-release-passwords.csv with 68,032 releases with a password):

Feature	Voyager 1	In voyager 2
Spotnet spots	D29	not yet; 2.76 M spots in the export
Posted NZBs read into releases (also NZBs inside archives)	D26, D28	not yet
Passwords (from spots, NZB meta, names)	D29, D26	only whether passworded (the prober); the export's 68 k passwords not imported
SFV grouping and naming	D34	not yet (SFV files aren't probe candidates)
Complete RAR listings by walking volume headers	D40	no: the prober reads the first volume's first article only
7z listings	D19	no: 7z-tail candidates are queued, not probed
Names from yEnc bodies for obfuscated subjects	D13, D21, D36	no: obfuscated and per-article subjects are only counted (part 5); their message-ids aren't stored, so a body path needs those ranges read again
Garbage dropped after probing (no real name, no password)	D42 (its second filter)	not yet; the header-time garbage rules are in (part 5)

Live indexing (the tail) runs since 2026-10-09.

Decisions

a. Chunk payload: a write-once bytea table in Postgres, partitioned by month, on the HDD; files on disk only if writes still limit. Accepted. b. A separate database on the same server. Accepted. c. Group list: editable, owner by priority number (above). Accepted. d. Reposts: separate releases in phase 1, merged in phase 2. Accepted. e. Headers through the coordinator's relay, with prefetch (part 1). Accepted. f. Random-named releases (no file with a readable name) keep no chunk in the header pass: their file keys and probe candidates only, until phase 2 names them (bodies) and fetches their segments again. The full history is ~3 TB with them, ~1.2–1.4 TB without (725 M of the 1.25 B kept files; LOG.md 2026-10-09). Accepted 2026-10-09, not built yet.