diff --git a/src/phlower/snapshot.py b/src/phlower/snapshot.py
index 682570d..2e2f18e 100644
--- a/src/phlower/snapshot.py
+++ b/src/phlower/snapshot.py
@@ -14,7 +14,7 @@
 
 logger = logging.getLogger(__name__)
 
-SNAPSHOT_VERSION = 1
+SNAPSHOT_VERSION = 2  # v2: hourly_workers keys are worker groups, not pod hostnames
 
 
 def _serialize_tdigest(td: TDigest | None) -> str | None:
diff --git a/src/phlower/sqlite_recovery.py b/src/phlower/sqlite_recovery.py
index 75c703f..68feec6 100644
--- a/src/phlower/sqlite_recovery.py
+++ b/src/phlower/sqlite_recovery.py
@@ -12,6 +12,7 @@
 from .snapshot import deserialize_aggregate
 from .sqlite_store import SQLiteStore
 from .store import DIGEST_HOT_WINDOW, Store
+from .workers import extract_worker_group
 
 logger = logging.getLogger(__name__)
 
@@ -100,12 +101,15 @@ def _load_counts(store: Store, sqlite_store: SQLiteStore, conn, since_ts: float)
         except ValueError:
             continue
 
+        # Resolve worker group here (outside the store lock taken in _flush_counts)
+        # so the regex doesn't run on the hot path that blocks live ingest.
+        worker = row["worker"]
         batch.append((
             task_name,
             state,
             row["minute_ts"],
             row["cnt"],
-            row["worker"],
+            extract_worker_group(worker) if worker else None,
             row["queue"],
             row["exception_type"],
         ))
@@ -130,11 +134,11 @@ def _flush_counts(store: Store, batch: list[tuple]) -> None:
     """
     hot_cutoff = int(time.time()) - DIGEST_HOT_WINDOW
     with store._lock:
-        for (task_name, state, minute_ts, cnt, worker, queue, exception_type) in batch:
+        for (task_name, state, minute_ts, cnt, worker_group, queue, exception_type) in batch:
             agg = store._get_or_create_task(task_name)
+            hour_ts = minute_ts // 3600 * 3600
 
             if minute_ts >= hot_cutoff:
-                # Recent data → per-minute buckets
                 bucket = agg._get_or_create_bucket(minute_ts)
                 bucket.count += cnt
                 if state == TaskState.SUCCESS:
@@ -144,8 +148,6 @@ def _flush_counts(store: Store, batch: list[tuple]) -> None:
                 elif state == TaskState.RETRY:
                     bucket.retry += cnt
             else:
-                # Old data → hourly rollups directly
-                hour_ts = minute_ts // 3600 * 3600
                 hb = agg.hourly_counts.get(hour_ts)
                 if hb is None:
                     hb = HourBucket(timestamp=hour_ts)
@@ -158,9 +160,8 @@ def _flush_counts(store: Store, batch: list[tuple]) -> None:
                 elif state == TaskState.RETRY:
                     hb.retry += cnt
 
-            hour_ts = minute_ts // 3600 * 3600
-            if worker:
-                agg._hourly_counter(agg.hourly_workers, hour_ts)[worker] += cnt
+            if worker_group:
+                agg._hourly_counter(agg.hourly_workers, hour_ts)[worker_group] += cnt
             if queue:
                 agg._hourly_counter(agg.hourly_queues, hour_ts)[queue] += cnt
             if exception_type:
diff --git a/src/phlower/store.py b/src/phlower/store.py
index e021344..30289bc 100644
--- a/src/phlower/store.py
+++ b/src/phlower/store.py
@@ -558,10 +558,11 @@ def process_succeeded(
             agg.active_count = max(0, agg.active_count - 1)
 
             rec = self._ensure_record(task_id, name)
-            worker = rec.worker
+            # K8s pod hashes churn — aggregate by stable group, not hostname.
+            worker_group = rec.worker_group
             queue = rec.queue
             agg.record_terminal_event(
-                TaskState.SUCCESS, ts, runtime_ms=runtime_ms, worker=worker, queue=queue
+                TaskState.SUCCESS, ts, runtime_ms=runtime_ms, worker=worker_group, queue=queue
             )
 
             rec.state = TaskState.SUCCESS
@@ -599,13 +600,13 @@ def process_failed(
             agg.active_count = max(0, agg.active_count - 1)
 
             rec = self._ensure_record(task_id, name)
-            worker = rec.worker
+            worker_group = rec.worker_group
             queue = rec.queue
             agg.record_terminal_event(
                 TaskState.FAILURE,
                 ts,
                 runtime_ms=runtime_ms,
-                worker=worker,
+                worker=worker_group,
                 queue=queue,
                 exception_type=exception_type,
             )