src/pobsync_backend/backup_runner.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
-from datetime import timedelta
+import os
+import socket
+from datetime import timedelta, timezone as datetime_timezone
 from pathlib import Path
 
 from django.db import transaction
@@ -158,10 +160,10 @@ def claim_next_queued_run() -> BackupRun | None:
         return run
 
 
-def reconcile_running_runs(*, grace_seconds: int = 300) -> int:
+def reconcile_running_runs(*, grace_seconds: int = 300, stale_worker_seconds: int = 24 * 60 * 60) -> int:
     reconciled = 0
     for run in BackupRun.objects.select_related("host").filter(status=BackupRun.Status.RUNNING).order_by("started_at", "id"):
-        if _reconcile_running_run(run=run, grace_seconds=grace_seconds):
+        if _reconcile_running_run(run=run, grace_seconds=grace_seconds, stale_worker_seconds=stale_worker_seconds):
             reconciled += 1
     return reconciled
 
@@ -176,7 +178,9 @@ def requested_options(run: BackupRun) -> dict[str, object]:
 def _running_result(*, run: BackupRun, dry_run: bool) -> dict[str, object]:
     result = dict(run.result) if isinstance(run.result, dict) else {}
     execution = {
+        **_worker_execution_details(),
         "started_at": (run.started_at or timezone.now()).isoformat(),
+        "heartbeat_at": timezone.now().isoformat(),
     }
     if dry_run:
         execution["log"] = str(dry_run_log_path(run.host.host, run_id=run.id))
@@ -185,24 +189,56 @@ def _running_result(*, run: BackupRun, dry_run: bool) -> dict[str, object]:
 
 
 def _run_cancel_requested(run_id: int) -> bool:
-    return BackupRun.objects.filter(id=run_id, status=BackupRun.Status.CANCELLED).exists()
+    try:
+        run = BackupRun.objects.only("id", "status", "result").get(id=run_id)
+    except BackupRun.DoesNotExist:
+        return True
+    if run.status == BackupRun.Status.CANCELLED:
+        return True
+    if run.status == BackupRun.Status.RUNNING:
+        _refresh_run_heartbeat(run)
+    return False
 
 
-def _reconcile_running_run(*, run: BackupRun, grace_seconds: int) -> bool:
+def _reconcile_running_run(*, run: BackupRun, grace_seconds: int, stale_worker_seconds: int) -> bool:
     result = run.result if isinstance(run.result, dict) else {}
     requested = result.get("requested") if isinstance(result.get("requested"), dict) else {}
+    stale_worker = _running_worker_timed_out(run=run, stale_worker_seconds=stale_worker_seconds)
     if not requested.get("dry_run"):
+        if stale_worker:
+            result.update(
+                {
+                    "ok": False,
+                    "host": run.host.host,
+                    "failure": {
+                        "category": "worker",
+                        "message": "The worker heartbeat stopped before the run finished.",
+                        "hint": "Check pobsync-worker.service logs before retrying the backup.",
+                    },
+                }
+            )
+            run.status = BackupRun.Status.FAILED
+            run.ended_at = timezone.now()
+            run.result = result
+            run.save(update_fields=["status", "ended_at", "result"])
+            return True
         return False
 
     log_path = _execution_log_path(result)
     log_tail = _read_log_tail(log_path) if log_path is not None else []
     terminal_log = _terminal_rsync_log(log_tail)
     timed_out = _running_dry_run_timed_out(run=run, grace_seconds=grace_seconds)
-    if not terminal_log and not timed_out:
+    if not terminal_log and not timed_out and not stale_worker:
         return False
 
-    exit_code = _exit_code_from_log(log_tail) or (124 if timed_out else 255)
+    exit_code = _exit_code_from_log(log_tail) or (124 if timed_out or stale_worker else 255)
     failure = classify_rsync_failure(exit_code, log_tail)
+    if stale_worker and not terminal_log:
+        failure = {
+            "category": "worker",
+            "message": "The worker heartbeat stopped before the dry-run finished.",
+            "hint": "Check pobsync-worker.service logs before retrying the dry-run.",
+        }
     result.update(
         {
             "ok": False,
@@ -226,6 +262,30 @@ def _reconcile_running_run(*, run: BackupRun, grace_seconds: int) -> bool:
     return True
 
 
+def _worker_execution_details() -> dict[str, object]:
+    return {
+        "worker_pid": os.getpid(),
+        "worker_host": socket.gethostname(),
+        "claimed_at": timezone.now().isoformat(),
+    }
+
+
+def _refresh_run_heartbeat(run: BackupRun, *, interval_seconds: int = 30) -> None:
+    result = run.result if isinstance(run.result, dict) else {}
+    execution = result.get("execution") if isinstance(result.get("execution"), dict) else {}
+    heartbeat_at = _parse_iso_datetime(execution.get("heartbeat_at"))
+    if heartbeat_at is not None and timezone.now() < heartbeat_at + timedelta(seconds=interval_seconds):
+        return
+    result["execution"] = {
+        **execution,
+        "worker_pid": os.getpid(),
+        "worker_host": socket.gethostname(),
+        "heartbeat_at": timezone.now().isoformat(),
+    }
+    run.result = result
+    run.save(update_fields=["result"])
+
+
 def _execution_log_path(result: dict[str, object]) -> Path | None:
     execution = result.get("execution") if isinstance(result.get("execution"), dict) else {}
     log = execution.get("log") or result.get("log")
@@ -266,3 +326,28 @@ def _running_dry_run_timed_out(*, run: BackupRun, grace_seconds: int) -> bool:
     if not isinstance(timeout_seconds, int) or timeout_seconds <= 0:
         timeout_seconds = DEFAULT_DRY_RUN_TIMEOUT_SECONDS
     return timezone.now() >= run.started_at + timedelta(seconds=timeout_seconds + grace_seconds)
+
+
+def _running_worker_timed_out(*, run: BackupRun, stale_worker_seconds: int) -> bool:
+    if stale_worker_seconds <= 0:
+        return False
+    result = run.result if isinstance(run.result, dict) else {}
+    execution = result.get("execution") if isinstance(result.get("execution"), dict) else {}
+    heartbeat_at = _parse_iso_datetime(execution.get("heartbeat_at"))
+    if heartbeat_at is None:
+        heartbeat_at = run.started_at
+    if heartbeat_at is None:
+        return False
+    return timezone.now() >= heartbeat_at + timedelta(seconds=stale_worker_seconds)
+
+
+def _parse_iso_datetime(value: object):
+    if not isinstance(value, str) or not value:
+        return None
+    try:
+        parsed = timezone.datetime.fromisoformat(value)
+    except ValueError:
+        return None
+    if timezone.is_naive(parsed):
+        return timezone.make_aware(parsed, timezone=datetime_timezone.utc)
+    return parsed

src/pobsync_backend/management/commands/run_pobsync_worker.py

@@ -19,6 +19,12 @@ class Command(BaseCommand):
         parser.add_argument("--once", action="store_true", help="Process one queued run and exit")
         parser.add_argument("--loop", action="store_true", help="Keep checking for queued runs")
         parser.add_argument("--interval", type=int, default=15, help="Loop interval in seconds")
+        parser.add_argument(
+            "--stale-running-seconds",
+            type=int,
+            default=24 * 60 * 60,
+            help="Mark running runs failed after this many seconds without a worker heartbeat; use 0 to disable",
+        )
 
     def handle(self, *args: Any, **options: Any) -> None:
         if not options["once"] and not options["loop"]:
@@ -26,14 +32,14 @@ class Command(BaseCommand):
 
         paths = PobsyncPaths(home=Path(options["prefix"]))
         while True:
-            count = self._run_once(prefix=paths.home)
+            count = self._run_once(prefix=paths.home, stale_running_seconds=int(options["stale_running_seconds"]))
             self.stdout.write(f"Ran {count} queued backup run(s).")
             if options["once"]:
                 return
             time.sleep(max(1, int(options["interval"])))
 
-    def _run_once(self, *, prefix: Path) -> int:
+    def _run_once(self, *, prefix: Path, stale_running_seconds: int = 24 * 60 * 60) -> int:
-        reconciled = reconcile_running_runs()
+        reconciled = reconcile_running_runs(stale_worker_seconds=stale_running_seconds)
         run = claim_next_queued_run()
         if run is None:
             return reconciled

src/pobsync_backend/templates/pobsync_backend/run_detail.html

@@ -79,6 +79,10 @@
         <div><strong>Created:</strong> {{ run.created_at }}</div>
         <div><strong>Started:</strong> {{ run.started_at|default:"" }}</div>
         <div><strong>Ended:</strong> {{ run.ended_at|default:"" }}</div>
+        {% if execution %}
+          <div><strong>Worker:</strong> {{ execution.worker_host|default:"unknown" }}{% if execution.worker_pid %} pid {{ execution.worker_pid }}{% endif %}</div>
+          <div><strong>Worker heartbeat:</strong> {{ execution.heartbeat_at|default:"" }}</div>
+        {% endif %}
       </div>
     </section>
 

src/pobsync_backend/tests/test_backup_worker.py

@@ -61,6 +61,9 @@ class BackupWorkerTests(TestCase):
                 def fake_run_scheduled(**kwargs):
                     run.refresh_from_db()
                     self.assertIn("execution", run.result)
+                    self.assertIn("worker_pid", run.result["execution"])
+                    self.assertIn("worker_host", run.result["execution"])
+                    self.assertIn("heartbeat_at", run.result["execution"])
                     return {
                         "ok": True,
                         "dry_run": False,
@@ -82,6 +85,57 @@ class BackupWorkerTests(TestCase):
         self.assertEqual(SnapshotRecord.objects.count(), 1)
         self.assertEqual(run.snapshot, SnapshotRecord.objects.get())
 
+    def test_worker_refreshes_heartbeat_while_run_is_active(self) -> None:
+        with TemporaryDirectory() as tmp:
+            GlobalConfig.objects.create(name="default", backup_root=str(Path(tmp) / "backups"))
+            host = HostConfig.objects.create(host="web-01", address="web-01.example.test")
+            run = queue_backup_run(host=host)
+
+            with patch("pobsync_backend.backup_runner.run_scheduled") as run_scheduled:
+                def fake_run_scheduled(**kwargs):
+                    run.refresh_from_db()
+                    old_heartbeat = timezone.now() - timedelta(seconds=120)
+                    run.result["execution"]["heartbeat_at"] = old_heartbeat.isoformat()
+                    run.save(update_fields=["result"])
+
+                    self.assertFalse(kwargs["cancel_check"]())
+                    run.refresh_from_db()
+                    self.assertGreater(
+                        timezone.datetime.fromisoformat(run.result["execution"]["heartbeat_at"]),
+                        old_heartbeat,
+                    )
+                    return {
+                        "ok": True,
+                        "dry_run": False,
+                        "host": host.host,
+                        "snapshot": "",
+                        "base": None,
+                        "rsync": {"exit_code": 0},
+                    }
+
+                run_scheduled.side_effect = fake_run_scheduled
+                Command()._run_once(prefix=Path(tmp) / "home")
+
+    def test_worker_reconciles_stale_real_run_after_heartbeat_timeout(self) -> None:
+        host = HostConfig.objects.create(host="web-01", address="web-01.example.test")
+        run = queue_backup_run(host=host)
+        run.status = BackupRun.Status.RUNNING
+        run.started_at = timezone.now() - timedelta(seconds=120)
+        run.result["execution"] = {
+            "worker_pid": 123,
+            "worker_host": "backup",
+            "heartbeat_at": (timezone.now() - timedelta(seconds=90)).isoformat(),
+        }
+        run.save(update_fields=["status", "started_at", "result"])
+
+        reconciled = reconcile_running_runs(stale_worker_seconds=30)
+
+        self.assertEqual(reconciled, 1)
+        run.refresh_from_db()
+        self.assertEqual(run.status, BackupRun.Status.FAILED)
+        self.assertEqual(run.result["failure"]["category"], "worker")
+        self.assertIn("heartbeat stopped", run.result["failure"]["message"])
+
     def test_worker_records_dry_run_log_path_while_running(self) -> None:
         with TemporaryDirectory() as tmp:
             GlobalConfig.objects.create(name="default", backup_root=str(Path(tmp) / "backups"))

src/pobsync_backend/tests/test_views.py

@@ -1373,6 +1373,29 @@ class ViewTests(TestCase):
         self.assertContains(response, "Cancel run")
         self.assertContains(response, reverse("cancel_run", args=[run.id]))
 
+    def test_run_detail_renders_worker_execution_metadata(self) -> None:
+        self.client.force_login(self.staff_user)
+        host = HostConfig.objects.create(host="web-01", address="web-01.example.test")
+        run = BackupRun.objects.create(
+            host=host,
+            status=BackupRun.Status.RUNNING,
+            result={
+                "execution": {
+                    "worker_host": "backup-01",
+                    "worker_pid": 4242,
+                    "heartbeat_at": "2026-05-21T10:30:00+00:00",
+                }
+            },
+        )
+
+        response = self.client.get(reverse("run_detail", args=[run.id]))
+
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, "Worker:")
+        self.assertContains(response, "backup-01")
+        self.assertContains(response, "pid 4242")
+        self.assertContains(response, "Worker heartbeat:")
+
     def test_cancel_run_marks_queued_run_cancelled(self) -> None:
         self.client.force_login(self.staff_user)
         host = HostConfig.objects.create(host="web-01", address="web-01.example.test")

src/pobsync_backend/views.py

@@ -448,6 +448,7 @@ def run_detail(request, run_id: int):
     rsync_result = result.get("rsync") if isinstance(result.get("rsync"), dict) else {}
     failure = result.get("failure") if isinstance(result.get("failure"), dict) else {}
     prune_result = result.get("prune") if isinstance(result.get("prune"), dict) else {}
+    execution = result.get("execution") if isinstance(result.get("execution"), dict) else {}
     rsync_log_path = _run_rsync_log_path(run)
     rsync_log_tail = _run_rsync_log_tail(rsync_result, rsync_log_path)
     requested = result.get("requested") if isinstance(result.get("requested"), dict) else {}
@@ -455,6 +456,7 @@ def run_detail(request, run_id: int):
         "run": run,
         "can_cancel": run.status in {BackupRun.Status.QUEUED, BackupRun.Status.RUNNING},
         "requested": requested,
+        "execution": execution,
         "stats": run_stats if isinstance(run_stats, dict) else {},
         "rsync": rsync_result,
         "rsync_command": _run_rsync_command(rsync_result),