fix: separate compaction metric correlation

crates/session-metrics/README.md

@@ -24,7 +24,7 @@ use session_metrics::{
 
 let metric = Metric::now("compact.start")
     .with_value(12_345.0)
-    .with_dimension("trigger", "automatic")
+    .with_dimension("trigger", "pre_run")
     .with_correlation_id("018f6f8a-9822-7b11-8b35-706f30313700");
 record_metric(
     &store,

crates/worker/src/compact/telemetry.rs

@@ -266,7 +266,7 @@ impl CompactAttempt {
                 self.source_segment_id.to_string(),
             ),
             ("mode".into(), self.mode.as_str().into()),
-            ("trigger".into(), self.mode.as_str().into()),
+            ("trigger".into(), self.threshold_policy.as_str().into()),
             (
                 "threshold_policy".into(),
                 self.threshold_policy.as_str().into(),
@@ -305,6 +305,15 @@ fn metric_with_context(
     metric
 }
 
+pub(crate) fn new_compact_metric_correlation_id(lifecycle_id: &str) -> String {
+    loop {
+        let correlation_id = uuid::Uuid::now_v7().to_string();
+        if correlation_id != lifecycle_id {
+            return correlation_id;
+        }
+    }
+}
+
 pub(crate) fn correlated_post_request_metric(
     kind: PostRequestMetric,
     correlation_id: &str,
@@ -330,10 +339,10 @@ pub(crate) fn safe_metric_number(value: u64) -> f64 {
 
 fn estimate_source(source: EstimateSource) -> &'static str {
     match source {
-        EstimateSource::Measured => "measured",
+        EstimateSource::Measured => "provider",
-        EstimateSource::Interpolated => "interpolated",
+        EstimateSource::Interpolated | EstimateSource::Extrapolated | EstimateSource::NoData => {
-        EstimateSource::Extrapolated => "extrapolated",
+            "fallback"
-        EstimateSource::NoData => "no_data",
+        }
     }
 }
 
@@ -357,14 +366,30 @@ mod tests {
         assert_eq!(start.name, "compact.start");
         assert_eq!(start.value, Some(MAX_SAFE_INTEGER as f64));
         assert_eq!(start.dimensions["mode"], "automatic");
-        assert_eq!(start.dimensions["trigger"], "automatic");
+        assert_eq!(start.dimensions["trigger"], "request_threshold");
         assert_eq!(start.dimensions["threshold_policy"], "request_threshold");
-        assert_eq!(start.dimensions["occupancy_source"], "measured");
+        assert_eq!(start.dimensions["occupancy_source"], "provider");
         assert!(start.correlation_id.is_some());
         assert!(start.dimensions.keys().all(|key| key.len() <= 32));
         assert!(start.dimensions.values().all(|value| value.len() <= 64));
     }
 
+    #[test]
+    fn occupancy_sources_match_the_public_provider_fallback_schema() {
+        assert_eq!(estimate_source(EstimateSource::Measured), "provider");
+        assert_eq!(estimate_source(EstimateSource::Interpolated), "fallback");
+        assert_eq!(estimate_source(EstimateSource::Extrapolated), "fallback");
+        assert_eq!(estimate_source(EstimateSource::NoData), "fallback");
+    }
+
+    #[test]
+    fn metric_correlation_id_is_distinct_from_lifecycle_identity() {
+        let lifecycle_id = uuid::Uuid::now_v7().to_string();
+        let correlation_id = new_compact_metric_correlation_id(&lifecycle_id);
+        assert_ne!(correlation_id, lifecycle_id);
+        assert!(uuid::Uuid::parse_str(&correlation_id).is_ok());
+    }
+
     #[test]
     fn post_request_metric_saturates_values_above_json_safe_integer() {
         let record = UsageRecord {

crates/worker/src/worker.rs

@@ -42,7 +42,7 @@ use manifest::{
 use crate::compact::state::CompactState;
 use crate::compact::telemetry::{
     CompactAttempt, CompactFailureCategory, CompactMode, CompactSuccessStats,
-    CompactThresholdPolicy, correlated_post_request_metric,
+    CompactThresholdPolicy, correlated_post_request_metric, new_compact_metric_correlation_id,
 };
 use crate::compact::usage_tracker::UsageTracker;
 use crate::feature::background::{BackgroundTaskRewriteGuard, FeatureBackgroundTaskRegistry};
@@ -4991,8 +4991,9 @@ impl<C: LlmClient + 'static, St: Store> Worker<C, St> {
         let history_items = self.session.history().items_cloned();
         let usage_history = self.usage_history();
         let pre_context = agen::token_counter::total_tokens(&history_items, &usage_history);
+        let metric_correlation_id = new_compact_metric_correlation_id(&lifecycle.compaction_id);
         let attempt = CompactAttempt::new(
-            lifecycle.compaction_id.clone(),
+            metric_correlation_id,
             source_location.session_id,
             source_location.segment_id,
             match trigger {

crates/worker/tests/compact_events_test.rs

@@ -760,7 +760,7 @@ async fn compact_emits_session_start_carrying_summary_and_task_snapshot() {
     assert_eq!(starts.len(), 1);
     assert_eq!(starts[0].segment_id, source_segment_id);
     assert_eq!(starts[0].metric.dimensions["mode"], "automatic");
-    assert_eq!(starts[0].metric.dimensions["trigger"], "automatic");
+    assert_eq!(starts[0].metric.dimensions["trigger"], "request_threshold");
     assert_eq!(
         starts[0].metric.dimensions["threshold_policy"],
         "request_threshold"
@@ -970,7 +970,7 @@ async fn pre_run_compact_publishes_runtime_progress_phases() {
         .unwrap();
     assert_eq!(start.segment_id, segment_before);
     assert_eq!(start.metric.dimensions["mode"], "automatic");
-    assert_eq!(start.metric.dimensions["trigger"], "automatic");
+    assert_eq!(start.metric.dimensions["trigger"], "pre_run");
     assert_eq!(start.metric.dimensions["threshold_policy"], "pre_run");
     let finish = metrics
         .iter()
@@ -1027,7 +1027,7 @@ async fn request_threshold_compact_publishes_runtime_progress() {
         .iter()
         .find(|record| record.metric.name == "compact.start")
         .unwrap();
-    assert_eq!(start.metric.dimensions["trigger"], "automatic");
+    assert_eq!(start.metric.dimensions["trigger"], "request_threshold");
     assert_eq!(
         start.metric.dimensions["threshold_policy"],
         "request_threshold"

docs/design/compaction.md

@@ -35,7 +35,7 @@ The important property is explainability: after compaction, records should still
 ## Metrics and comparison procedure
 
 Compaction measurements stay out of the ordinary transcript. They are appended as
-`session.metrics` extensions and are read only through the explicit
+`metrics` extensions and are read only through the explicit
 `session-metrics` reader/export path. `read_session_metrics` attaches the durable
 `segment_id` and `SegmentStart.compacted_from` lineage to each record.