Try resolve missing items in cache

Author: wjsi

mars/services/scheduling/utils.py

@@ -15,6 +15,9 @@
 import asyncio
 import contextlib
 import sys
+import time
+from collections import OrderedDict
+from typing import Dict, Mapping, Optional, TypeVar, Iterator
 
 from ... import oscar as mo
 from ...lib.aio import alru_cache
@@ -58,3 +61,59 @@ async def redirect_subtask_errors(actor: mo.Actor, subtasks):
             )
         await asyncio.wait(coros)
         raise
+
+
+ResultType = TypeVar("ResultType")
+
+
+class ResultCache(Mapping[str, ResultType]):
+    _cache: Dict[str, ResultType]
+    _cache_time: Dict[str, float]
+    _duration: float
+
+    def __init__(self, duration: float = 120):
+        self._cache = dict()
+        self._cache_time = OrderedDict()
+        self._duration = duration
+
+    def __getitem__(self, item: str):
+        self._del_expired_items()
+        return self._cache[item]
+
+    def get(
+        self, key: str, default: Optional[ResultType] = None
+    ) -> Optional[ResultType]:
+        self._del_expired_items()
+        return self._cache.get(key, default)
+
+    def _del_expired_items(self):
+        keys = []
+        expire_time = time.time() - self._duration
+        for key, store_time in self._cache_time.items():
+            if store_time < expire_time:
+                break
+            keys.append(key)
+        for key in keys:
+            self._delitem(key)
+
+    def __setitem__(self, key: str, value):
+        self._del_expired_items()
+        self._cache[key] = value
+        self._cache_time[key] = time.time()
+
+    def _delitem(self, key: str):
+        del self._cache[key]
+        self._cache_time.pop(key, None)
+
+    def __delitem__(self, key: str):
+        self._delitem(key)
+        self._del_expired_items()
+
+    def __len__(self) -> int:
+        self._del_expired_items()
+        return len(self._cache)
+
+    def __iter__(self) -> Iterator[str]:
+        self._del_expired_items()
+        return iter(self._cache)
+

mars/services/scheduling/worker/execution/actor.py

@@ -26,6 +26,7 @@
 from ....cluster import ClusterAPI
 from ....core import ActorCallback
 from ....subtask import Subtask, SubtaskAPI, SubtaskResult, SubtaskStatus
+from ...utils import ResultCache
 from ..queues import SubtaskPrepareQueueActor, SubtaskExecutionQueueActor
 from ..quota import QuotaActor
 from ..slotmanager import SlotManagerActor
@@ -49,18 +50,21 @@ class SubtaskExecutionActor(mo.Actor):
 
     _subtask_api: SubtaskAPI
     _subtask_preparer: SubtaskPreparer
+    _subtask_result_cache: ResultCache[SubtaskResult]
 
     def __init__(
         self,
         subtask_max_retries: int = None,
         enable_kill_slot: bool = True,
     ):
         self._pred_key_mapping_dag = DAG()
-        self._subtask_caches = dict()
-        self._subtask_executions = dict()
         self._prepare_queue_ref = None
         self._execution_queue_ref = None
 
+        self._subtask_caches = dict()
+        self._subtask_executions = dict()
+        self._subtask_result_cache = ResultCache()
+
         self._subtask_max_retries = subtask_max_retries or DEFAULT_SUBTASK_MAX_RETRIES
         self._enable_kill_slot = enable_kill_slot
 
@@ -249,7 +253,6 @@ async def submit_subtasks(
                 supervisor_address=supervisor_address,
                 band_name=band_name,
             )
-            self._subtask_caches.pop(subtask.subtask_id, None)
             self._subtask_executions[subtask.subtask_id] = subtask_info
             put_delays.append(
                 self._prepare_queue_ref.put.delay(
@@ -322,7 +325,7 @@ async def cancel_subtasks(
                 continue
             if not subtask_info.result.status.is_done:
                 self._fill_result_with_exc(subtask_info, exc_cls=asyncio.CancelledError)
-                infos_to_report.append(subtask_info)
+            infos_to_report.append(subtask_info)
         await self._report_subtask_results(infos_to_report)
 
     async def wait_subtasks(self, subtask_ids: List[str]):
@@ -654,6 +657,5 @@ async def _forward_subtask_info(self, subtask_info: SubtaskExecutionInfo):
             await self._execution_queue_ref.put(
                 subtask_id, subtask_info.band_name, subtask_info.priority
             )
-            self.uncache_subtasks([subtask_id])
         except PrepareFastFailed:
             self._subtask_executions.pop(subtask_id, None)

mars/services/subtask/worker/tests/subtask_processor.py

@@ -50,10 +50,19 @@ def _execute_operand(self, ctx: Dict[str, Any], op: OperandType):
                     continue
                 self.assert_object_consistent(out, ctx[out.key])
 
-    async def done(self):
-        await super().done()
+    def _unregister_executors(self):
         for op in self._operand_executors:
             try:
                 op.unregister_executor()
             except KeyError:
                 pass
+
+    async def _release_scheduling(self):
+        # once the operand stops running, the slot may be reused immediately
+        # thus executors must be cleaned in time
+        self._unregister_executors()
+        await super()._release_scheduling()
+
+    async def done(self):
+        await super().done()
+        self._unregister_executors()