diff --git a/archivebox/__init__.py b/archivebox/__init__.py
index 6b301e1f..136546e8 100755
--- a/archivebox/__init__.py
+++ b/archivebox/__init__.py
@@ -84,6 +84,7 @@ ARCHIVEBOX_BUILTIN_PLUGINS = {
     'config': PACKAGE_DIR / 'config',
     'core': PACKAGE_DIR / 'core',
     'crawls': PACKAGE_DIR / 'crawls',
+    'queues': PACKAGE_DIR / 'queues',
     'seeds': PACKAGE_DIR / 'seeds',
     'actors': PACKAGE_DIR / 'actors',
     # 'search': PACKAGE_DIR / 'search',
diff --git a/archivebox/actors/actor.py b/archivebox/actors/actor.py
index 9c9db5d9..7c92b15e 100644
--- a/archivebox/actors/actor.py
+++ b/archivebox/actors/actor.py
@@ -75,7 +75,7 @@ class ActorType(Generic[ModelType]):
     _SPAWNED_ACTOR_PIDS: ClassVar[list[psutil.Process]] = []      # used to record all the pids of Actors spawned on the class
     
     ### Instance attributes (only used within an actor instance inside a spawned actor thread/process)
-    pid: int
+    pid: int = os.getpid()
     idle_count: int = 0
     launch_kwargs: LaunchKwargs = {}
     mode: Literal['thread', 'process'] = 'process'
@@ -290,7 +290,7 @@ class ActorType(Generic[ModelType]):
         Override this in the subclass to define the QuerySet of objects that the Actor is going to poll for new work.
         (don't limit, order, or filter this by retry_at or status yet, Actor.get_queue() handles that part)
         """
-        return cls.Model.objects.all()
+        return cls.Model.objects.filter()
     
     @classproperty
     def final_q(cls) -> Q:
@@ -438,25 +438,30 @@ class ActorType(Generic[ModelType]):
         assert select_top_canidates_sql.startswith('SELECT ')
         
         # e.g. UPDATE core_archiveresult SET status='%s', retry_at='%s' WHERE status NOT IN (...) AND retry_at <= '...'
-        update_claimed_obj_sql, update_params = self._sql_for_update_claimed_obj(qs=qs, update_kwargs=self.get_update_kwargs_to_claim_obj())
-        assert update_claimed_obj_sql.startswith('UPDATE ')
+        update_claimed_obj_sql, update_params = self._sql_for_update_claimed_obj(qs=self.qs.all(), update_kwargs=self.get_update_kwargs_to_claim_obj())
+        assert update_claimed_obj_sql.startswith('UPDATE ') and 'WHERE' not in update_claimed_obj_sql
         db_table = self.Model._meta.db_table  # e.g. core_archiveresult
         
         # subquery gets the pool of the top candidates e.g. self.get_queue().only('id')[:CLAIM_FROM_TOP_N]
         # main query selects a random one from that pool, and claims it using .update(status=ACTIVE_STATE, retry_at=<now + MAX_TICK_TIME>)
         # this is all done in one atomic SQL query to avoid TOCTTOU race conditions (as much as possible)
         atomic_select_and_update_sql = f"""
-            {update_claimed_obj_sql} AND "{db_table}"."id" = (
-                SELECT "{db_table}"."id" FROM (
-                    {select_top_canidates_sql}
-                ) candidates
+            with top_candidates AS ({select_top_canidates_sql})
+            {update_claimed_obj_sql}
+            WHERE "{db_table}"."id" IN (
+                SELECT id FROM top_candidates
                 ORDER BY RANDOM()
                 LIMIT 1
             )
             RETURNING *;
         """
+        
+        # import ipdb; ipdb.set_trace()
+
         try:
-            return self.Model.objects.raw(atomic_select_and_update_sql, (*update_params, *select_params))[0]
+            updated = qs.raw(atomic_select_and_update_sql, (*select_params, *update_params))
+            assert len(updated) <= 1, f'Expected to claim at most 1 object, but Django modified {len(updated)} objects!'
+            return updated[0]
         except IndexError:
             if self.get_queue().exists():
                 raise ActorObjectAlreadyClaimed(f'Unable to lock the next {self.Model.__name__} object from {self}.get_queue().first()')
@@ -548,7 +553,7 @@ def compile_sql_select(queryset: QuerySet, filter_kwargs: dict[str, Any] | None=
     return select_sql, select_params
 
 
-def compile_sql_update(queryset: QuerySet, update_kwargs: dict[str, Any], filter_kwargs: dict[str, Any] | None=None) -> tuple[str, tuple[Any, ...]]:
+def compile_sql_update(queryset: QuerySet, update_kwargs: dict[str, Any]) -> tuple[str, tuple[Any, ...]]:
     """
     Compute the UPDATE query SQL for a queryset.filter(**filter_kwargs).update(**update_kwargs) call
     Returns a tuple of (sql, params) where sql is a template string containing %s (unquoted) placeholders for the params
@@ -562,11 +567,8 @@ def compile_sql_update(queryset: QuerySet, update_kwargs: dict[str, Any], filter
     """
     assert isinstance(queryset, QuerySet), f'compile_sql_update(...) first argument must be a QuerySet, got: {type(queryset).__name__} instead'
     assert isinstance(update_kwargs, dict), f'compile_sql_update(...) update_kwargs argument must be a dict[str, Any], got: {type(update_kwargs).__name__} instead'
-    assert filter_kwargs is None or isinstance(filter_kwargs, dict), f'compile_sql_update(...) filter_kwargs argument must be a dict[str, Any], got: {type(filter_kwargs).__name__} instead'
     
-    queryset = queryset._chain()                      # type: ignore   # copy queryset to avoid modifying the original
-    if filter_kwargs:
-        queryset = queryset.filter(**filter_kwargs)
+    queryset = queryset._chain().all()                # type: ignore   # copy queryset to avoid modifying the original and clear any filters
     queryset.query.clear_ordering(force=True)                          # clear any ORDER BY clauses
     queryset.query.clear_limits()                                      # clear any LIMIT clauses aka slices[:n]
     queryset._for_write = True                        # type: ignore
@@ -576,5 +578,12 @@ def compile_sql_update(queryset: QuerySet, update_kwargs: dict[str, Any], filter
     
     # e.g. UPDATE core_archiveresult SET status='%s', retry_at='%s' WHERE status NOT IN (%s, %s, %s) AND retry_at <= %s
     update_sql, update_params = query.get_compiler(queryset.db).as_sql()
+    
+    # make sure you only pass a raw queryset with no .filter(...) clauses applied to it, the return value is designed to used
+    # in a manually assembled SQL query with its own WHERE clause later on
+    assert 'WHERE' not in update_sql, f'compile_sql_update(...) should only contain a SET statement but it tried to return a query with a WHERE clause: {update_sql}'
+    
+    # print(update_sql, update_params)
+
     return update_sql, update_params
 
diff --git a/archivebox/actors/orchestrator.py b/archivebox/actors/orchestrator.py
index c3297c70..7457372b 100644
--- a/archivebox/actors/orchestrator.py
+++ b/archivebox/actors/orchestrator.py
@@ -102,7 +102,7 @@ class Orchestrator:
         # returns a list of objects that are in the queues of all actor types but not in the queues of any other actor types
 
         return any(
-            queue.filter(retry_at__gt=timezone.now()).exists()
+            queue.filter(retry_at__gte=timezone.now()).exists()
             for queue in all_queues.values()
         )
     
@@ -163,7 +163,7 @@ class Orchestrator:
 
                 for actor_type, queue in all_queues.items():
                     next_obj = queue.first()
-                    print(f'🏃‍♂️ {self}.runloop() {actor_type.__name__.ljust(20)} queue={str(queue.count()).ljust(3)} next={next_obj.abid if next_obj else "None"} {next_obj.status if next_obj else "None"} {(timezone.now() - next_obj.retry_at).total_seconds() if next_obj else "None"}')
+                    print(f'🏃‍♂️ {self}.runloop() {actor_type.__name__.ljust(20)} queue={str(queue.count()).ljust(3)} next={next_obj.abid if next_obj else "None"} {next_obj.status if next_obj else "None"} {(timezone.now() - next_obj.retry_at).total_seconds() if next_obj and next_obj.retry_at else "None"}')
                     try:
                         existing_actors = actor_type.get_running_actors()
                         all_existing_actors.extend(existing_actors)