Add early stop in pool.

testplan/common/entity/base.py

@@ -270,12 +270,39 @@ def start_in_pool(self, pool):
                 resource.wait(resource.STATUS.STARTED)
                 resource.logger.info("%s started", resource)
 
-    def stop(self, is_reversed=False):
+    def sync_stop_resource(self, resource: "Resource"):
+        """
+        Stop a resource and log exceptions.
+        """
+        if resource.status in (
+            resource.STATUS.STOPPING,
+            resource.STATUS.STOPPED,
+        ):
+            return
+
+        resource.logger.info("Stopping %s", resource)
+        try:
+            resource.stop()
+        except Exception:
+            self._record_resource_exception(
+                message="While stopping resource {resource}:\n"
+                "{traceback_exc}\n{fetch_msg}",
+                resource=resource,
+                msg_store=self.stop_exceptions,
+            )
+
+            # Resource status should be STOPPED even it failed to stop
+            resource.force_stopped()
+        else:
+            if resource.async_start:
+                resource.wait(resource.STATUS.STOPPED)
+        resource.logger.info("%s stopped", resource)
+
+    def stop(self, is_reversed: bool = False):
         """
         Stop all resources, optionally in reverse order, and log exceptions.
 
         :param is_reversed: flag whether to stop resources in reverse order
-        :type is_reversed: ``bool``
         """
         resources = list(self._resources.values())
         if is_reversed is True:
@@ -284,6 +311,11 @@ def stop(self, is_reversed=False):
         # Stop all resources
         resources_to_wait_for = []
         for resource in resources:
+            if resource.status in (
+                resource.STATUS.STOPPING,
+                resource.STATUS.STOPPED,
+            ):
+                continue
             try:
                 resource.stop()
             except Exception:
@@ -335,6 +367,11 @@ def stop_in_pool(self, pool, is_reversed=False):
         # Stop all resources
         resources_to_wait_for = []
         for resource in resources:
+            if resource.status in (
+                resource.STATUS.STOPPING,
+                resource.STATUS.STOPPED,
+            ):
+                continue
             pool.apply_async(
                 self._log_exception(
                     resource, resource.stop, self.stop_exceptions

testplan/runners/pools/base.py

@@ -7,7 +7,16 @@
 import threading
 import time
 import traceback
-from typing import Dict, Generator, List, Optional, Tuple, Type, Union
+from typing import (
+    Dict,
+    Generator,
+    List,
+    Optional,
+    Tuple,
+    Type,
+    Union,
+    Callable,
+)
 
 from schema import And, Or, Use
 
@@ -36,6 +45,9 @@ def __init__(self) -> None:
         self.q = queue.PriorityQueue()
         self.count = 0
 
+    def size(self) -> int:
+        return self.q.qsize()
+
     def put(self, priority: int, item: str) -> None:
         self.q.put((priority, self.count, item))
         self.count += 1
@@ -336,6 +348,7 @@ class Pool(Executor):
 
     CONFIG = PoolConfig
     CONN_MANAGER = QueueServer
+    RESERVE_WORKER_NUM = 3
 
     def __init__(
         self,
@@ -367,7 +380,9 @@ def __init__(
         # Methods for handling different Message types. These are expected to
         # take the worker, request and response objects as the only required
         # positional args.
-        self._request_handlers = {
+        self._request_handlers: Dict[
+            str, Callable[[Worker, Message, Message], None]
+        ] = {
             Message.ConfigRequest: self._handle_cfg_request,
             Message.TaskPullRequest: self._handle_taskpull_request,
             Message.TaskResults: self._handle_taskresults,
@@ -382,6 +397,13 @@ def __init__(
         # NOTE: the critical section would be rather meaningless
         self._discard_pending_lock = threading.RLock()
         self._discard_pending = False
+        self._stopping_queue = []
+        self.worker_status = {
+            "active": [],
+            "inactive": [],
+            "initializing": [],
+            "abort": [],
+        }
 
     def uid(self) -> str:
         """Pool name."""
@@ -532,6 +554,10 @@ def _handle_taskpull_request(
                 try:
                     priority, uid = self.unassigned.get()
                 except queue.Empty:
+                    self.logger.debug("No tasks to assign to %s", worker)
+                    if self._early_stop_worker(worker.uid()):
+                        worker.respond(response.make(Message.Stop))
+                        return
                     break
 
                 task = self._input[uid]
@@ -699,6 +725,10 @@ def _handle_setupfailed(
         worker.respond(response.make(Message.Ack))
         self._decommission_worker(worker, "Aborting {}, setup failed.")
 
+    def _early_stop_worker(self, worker_uid: Union[str, int]) -> bool:
+        # Thread pool doesn't support early stop
+        return False
+
     def _decommission_worker(self, worker: Worker, message: str) -> None:
         """
         Decommission a worker by move all assigned task back to pool
@@ -721,12 +751,7 @@ def _workers_monitoring(self) -> None:
         1) handler status
         2) heartbeat if available
         """
-        previous_status = {
-            "active": [],
-            "inactive": [],
-            "initializing": [],
-            "abort": [],
-        }
+
         loop_interval = self.cfg.worker_heartbeat or 5  # seconds
         break_outer_loop = False
 
@@ -747,8 +772,9 @@ def _workers_monitoring(self) -> None:
                             and self.status != self.status.STOPPING
                             and self.status != self.status.STOPPED
                         ):
-                            if self._handle_inactive(worker, reason):
-                                status = "active"
+                            if worker.uid() not in self._stopping_queue:
+                                if self._handle_inactive(worker, reason):
+                                    status = "active"
                         else:
                             self.logger.user_info(
                                 "%s is aborting/stopping, exit monitor.", self
@@ -761,12 +787,12 @@ def _workers_monitoring(self) -> None:
             if break_outer_loop:
                 break
 
-            if hosts_status != previous_status:
+            if hosts_status != self.worker_status:
                 self.logger.info(
                     "Hosts status update at %s", datetime.datetime.now()
                 )
                 self.logger.info(pprint.pformat(hosts_status))
-                previous_status = hosts_status
+                self.worker_status = hosts_status
 
             if (
                 not hosts_status["active"]

testplan/runners/pools/remote.py

@@ -287,6 +287,8 @@ class RemotePool(Pool):
 
     CONFIG = RemotePoolConfig
     CONN_MANAGER = ZMQServer
+    QUEUE_WAIT_INTERVAL = 3
+    MAX_THREAD_POOL_SIZE = 5
 
     def __init__(
         self,
@@ -322,7 +324,6 @@ def __init__(
         options.update(self.filter_locals(locals()))
         super(RemotePool, self).__init__(**options)
         self._options = options  # pass to remote worker later
-
         self._request_handlers[
             Message.MetadataPull
         ] = self._worker_setup_metadata
@@ -341,7 +342,9 @@ def resource_monitor_address(self) -> Optional[str]:
             return self.parent.resource_monitor_server.address
 
     @staticmethod
-    def _worker_setup_metadata(worker, request, response) -> None:
+    def _worker_setup_metadata(
+        worker: RemoteWorker, _: Message, response: Message
+    ) -> None:
         worker.respond(
             response.make(Message.Metadata, data=worker.setup_metadata)
         )
@@ -386,6 +389,26 @@ def _start_thread_pool(self) -> None:
                     "Please upgrade to the suggested python interpreter."
                 )
 
+    def _early_stop_worker(self, worker_uid: Union[str, int]) -> bool:
+        with self._pool_lock:
+            if self.pool and (worker_uid not in self._stopping_queue):
+                alive_worker_ids = set(
+                    [worker.uid() for worker in self.worker_status["active"]]
+                )
+                if self.RESERVE_WORKER_NUM + self.unassigned.size() < len(
+                    alive_worker_ids - set(self._stopping_queue)
+                ):
+                    self.logger.user_info(
+                        "Early stop worker %s", self._workers[worker_uid]
+                    )
+                    self._stopping_queue.append(worker_uid)
+                    self.pool.apply_async(
+                        self._workers.sync_stop_resource,
+                        (self._workers[worker_uid],),
+                    )
+                    return True
+        return False
+
     def starting(self) -> None:
         self._start_thread_pool()
         super(RemotePool, self).starting()