fix: use prior active window baseline for #749

docs/PREDICTIVE_RESOURCE_ALLOCATION.md

@@ -12,8 +12,8 @@ The predictor reads two data sources:
 2. **Heartbeat logs** (`heartbeat/ticks_*.jsonl`) — Gitea availability,
    local inference health
 
-It compares a **recent window** (last N hours) against a **baseline window**
+It compares a **recent window** (last N hours of activity) against the **previous active window**
-(previous N hours) to detect surges and degradation.
+(previous N hours ending at the most recent event before the current window) so sparse telemetry still yields a meaningful baseline.
 
 ## Output Contract
 

scripts/predictive_resource_allocator.py

@@ -90,13 +90,19 @@ def compute_rates(
 
     latest = max(_parse_ts(r["timestamp"]) for r in rows)
     recent_cutoff = latest - timedelta(hours=horizon_hours)
-    baseline_cutoff = latest - timedelta(hours=horizon_hours * 2)
 
     recent = [r for r in rows if _parse_ts(r["timestamp"]) >= recent_cutoff]
-    baseline = [
+
-        r for r in rows
+    earlier = [r for r in rows if _parse_ts(r["timestamp"]) < recent_cutoff]
-        if baseline_cutoff <= _parse_ts(r["timestamp"]) < recent_cutoff
+    if earlier:
-    ]
+        previous_latest = max(_parse_ts(r["timestamp"]) for r in earlier)
+        previous_cutoff = previous_latest - timedelta(hours=horizon_hours)
+        baseline = [
+            r for r in earlier
+            if _parse_ts(r["timestamp"]) >= previous_cutoff
+        ]
+    else:
+        baseline = []
 
     recent_rate = len(recent) / max(horizon_hours, 1)
     baseline_rate = (

tests/test_predictive_resource_allocator.py

@@ -99,6 +99,17 @@ class TestComputeRates:
         _, _, surge, _, _ = compute_rates(rows, horizon_hours=6)
         assert surge < 1.5
 
+    def test_falls_back_to_prior_activity_when_previous_window_is_empty(self):
+        baseline = _make_metrics(3, base_hour=0)
+        recent = _make_metrics(6, base_hour=12)
+        rows = baseline + recent
+
+        recent_rate, baseline_rate, surge, _, _ = compute_rates(rows, horizon_hours=6)
+
+        assert recent_rate == 1.0
+        assert baseline_rate == 0.5
+        assert surge == 2.0
+
 
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