SOW-0122: fast --list-invocations and stock IDX alignment; track remaining CLI gaps

.agents/sow/SOW-status.md

@@ -11,7 +11,8 @@ order; the user may reorder it.
 1. SOW-0161 - File indexer source posting membership (completed 2026-11-01).
 2. SOW-0160 - Go XZ reader dictionary allocation (completed 2026-11-04: Go
    writer declares 256 KiB).
-3. SOW-0122 - journalctl performance follow-ups.
+3. SOW-0122 - journalctl performance follow-ups (completed 2026-11-01; gaps
+   tracked by SOW-0166, SOW-0167, SOW-0168).
 4. SOW-0097 - Go duplication debt.
 5. SOW-0098 - Rust legacy core / `jf` duplication debt (feeds SOW-0162).
 6. SOW-0153 - Consumer docs release clarity.
@@ -25,11 +26,15 @@ order; the user may reorder it.
     adopts Go's zero floor after a Netdata caller check).
 13. SOW-0066 - v1.0.0 API freeze and release (not scheduled; user decision
     2026-11-03).
-14. SOW-0170 - Rust rewrite of Netdata systemd-journal.plugin (tracked; not
+14. SOW-0166 - Directory realtime seek cost.
+15. SOW-0167 - Go reader eager entry-array load.
+16. SOW-0168 - journalctl follow wait and error parity (decided 2026-11-03:
+    cheap polling first).
+17. SOW-0170 - Rust rewrite of Netdata systemd-journal.plugin (tracked; not
     now, by user decision 2026-11-03).
-15. SOW-0171 - Continue sealing when reopening a sealed file (tracked; SOW-0156
+18. SOW-0171 - Continue sealing when reopening a sealed file (tracked; SOW-0156
     decision N1, 2026-11-03).
-16. SOW-0172 - Rust Log fails late on a relative directory (tracked 2026-11-03
+19. SOW-0172 - Rust Log fails late on a relative directory (tracked 2026-11-03
     from SOW-0156; needs a user decision).
 
 ## Current
@@ -44,8 +49,12 @@ None.
   line numbers need refreshing at activation.
 - SOW-0098 - Rust Legacy Core Duplication Debt: real `jf` duplication; feeds
   SOW-0162.
-- SOW-0122 - Journalctl Performance Followups: unmeasured large-input and
-  `--follow` scalability work for the CLIs.
+- SOW-0166 - Directory Realtime Seek Cost: directory `--since` 17x slower than
+  stock (SOW-0122 measurement).
+- SOW-0167 - Go Reader Eager Entry Array Load: every Go open loads the full
+  entry array.
+- SOW-0168 - Journalctl Follow Wait And Error Parity: decided 2026-11-03
+  (cheap polling first).
 - SOW-0125 - Netdata Filter Operators Gap Analysis: feature analysis; needs
   semantic decisions before implementation.
 - SOW-0153 - Consumer Documentation Release Clarity: stale `go/v0.3.0` text and
@@ -80,6 +89,8 @@ None.
   read and continue every file earlier releases wrote. Follow-ups: SOW-0171,
   SOW-0172.
 
+- SOW-0122 - Journalctl Performance Followups: completed 2026-11-01;
+  `--list-invocations` 8-120x faster and IDX alignment matches stock.
 - SOW-0161 - File Indexer Source Posting Membership: completed 2026-11-01;
   source histograms count the captured ENTRY population once per entry.
 - SOW-0137 - Rust Writer Residual Array-Open Performance: completed 2026-11-01.

.agents/sow/pending/SOW-0166-20261101-directory-realtime-seek-cost.md

@@ -0,0 +1,87 @@
+# SOW-0166 - Directory Realtime Seek Cost
+
+## Status
+
+Status: open
+
+Sub-state: measured gap from SOW-0122; not activated.
+
+## Requirements
+
+### Purpose
+
+Directory realtime seeks (`--since`, `SeekRealtimeUsec` on directory readers)
+should cost about what stock does, independent of how many entries precede the
+target.
+
+### User Request
+
+Follow-up of SOW-0122 measurement (performance contract in `AGENTS.md`).
+
+### Assistant Understanding
+
+Facts (SOW-0122, `.local/sow0122/report.md`, 300-file 1.5M-entry directory):
+
+- `--since/--until` 60 s window mid-directory: Rust 3.54 s, Go 3.46 s, stock
+  v262 0.21 s. `--since` at the last minute: Rust 17.3 s, Go 5.4 s, stock
+  0.16 s (one-off run). Single-file seeks are at parity.
+
+Inferences (unverified):
+
+- Rust `rust/src/journal/src/directory.rs` `fill_candidate` (around lines
+  375-392) may step and discard older entries file by file instead of seeking
+  each file by realtime or skipping files whose tail is older than the target.
+  The Go directory path is not traced yet.
+
+### Acceptance Criteria
+
+- Trace both languages, fix the per-file positioning to use journal-native
+  realtime seeks (entry-array bisection) and header head/tail bounds.
+- On the SOW-0122 300-file directory fixture and procedure (SOW-0122
+  Implications And Decisions: 3 runs, median wall time), the 60 s
+  `--since/--until` window and the last-minute `--since` each run in at most
+  2x stock's median, or under 0.5 s when stock is below 0.25 s, in both
+  languages (proposed gate, agent-chosen; confirm at activation). The query
+  matrix and directory matrix still pass.
+
+## Analysis
+
+Pending activation.
+
+## Pre-Implementation Gate
+
+Not started.
+
+## Implications And Decisions
+
+None yet.
+
+## Plan
+
+Pending activation.
+
+## Execution Log
+
+### 2026-11-01
+
+- Created from SOW-0122 measurements.
+
+## Validation
+
+Pending.
+
+## Outcome
+
+Pending.
+
+## Lessons Extracted
+
+None yet.
+
+## Followup
+
+None yet.
+
+## Regression Log
+
+None.