Changing the way workers are forked

bin/ansible

@@ -60,6 +60,7 @@ if __name__ == '__main__':
 
     try:
         display = Display()
+        display.debug("starting run")
 
         sub = None
         try:

lib/ansible/executor/process/worker.py

@@ -59,14 +59,18 @@ class WorkerProcess(multiprocessing.Process):
     for reading later.
     '''
 
-    def __init__(self, tqm, main_q, rslt_q, hostvars_manager, loader):
+    def __init__(self, rslt_q, task_vars, host, task, play_context, loader, variable_manager, shared_loader_obj):
 
         super(WorkerProcess, self).__init__()
         # takes a task queue manager as the sole param:
-        self._main_q   = main_q
         self._rslt_q            = rslt_q
-        self._hostvars = hostvars_manager
+        self._task_vars         = task_vars
+        self._host              = host
+        self._task              = task
+        self._play_context      = play_context
         self._loader            = loader
+        self._variable_manager  = variable_manager
+        self._shared_loader_obj = shared_loader_obj
 
         # dupe stdin, if we have one
         self._new_stdin = sys.stdin
@@ -97,73 +101,45 @@ class WorkerProcess(multiprocessing.Process):
         if HAS_ATFORK:
             atfork()
 
-        while True:
-            task = None
         try:
-                #debug("waiting for work")
-                (host, task, basedir, zip_vars, compressed_vars, play_context, shared_loader_obj) = self._main_q.get(block=False)
-
-                if compressed_vars:
-                    job_vars = json.loads(zlib.decompress(zip_vars))
-                else:
-                    job_vars = zip_vars
-
-                job_vars['hostvars'] = self._hostvars.hostvars()
-
-                debug("there's work to be done! got a task/handler to work on: %s" % task)
-
-                # because the task queue manager starts workers (forks) before the
-                # playbook is loaded, set the basedir of the loader inherted by
-                # this fork now so that we can find files correctly
-                self._loader.set_basedir(basedir)
-
-                # Serializing/deserializing tasks does not preserve the loader attribute,
-                # since it is passed to the worker during the forking of the process and
-                # would be wasteful to serialize. So we set it here on the task now, and
-                # the task handles updating parent/child objects as needed.
-                task.set_loader(self._loader)
-
             # execute the task and build a TaskResult from the result
-                debug("running TaskExecutor() for %s/%s" % (host, task))
+            debug("running TaskExecutor() for %s/%s" % (self._host, self._task))
             executor_result = TaskExecutor(
-                    host,
-                    task,
-                    job_vars,
-                    play_context,
+                self._host,
+                self._task,
+                self._task_vars,
+                self._play_context,
                 self._new_stdin,
                 self._loader,
-                    shared_loader_obj,
+                self._shared_loader_obj,
             ).run()
-                debug("done running TaskExecutor() for %s/%s" % (host, task))
-                task_result = TaskResult(host, task, executor_result)
+
+            debug("done running TaskExecutor() for %s/%s" % (self._host, self._task))
+            self._host.vars = dict()
+            self._host.groups = []
+            task_result = TaskResult(self._host, self._task, executor_result)
 
             # put the result on the result queue
             debug("sending task result")
             self._rslt_q.put(task_result)
             debug("done sending task result")
 
-            except queue.Empty:
-                time.sleep(0.0001)
         except AnsibleConnectionFailure:
-                try:
-                    if task:
-                        task_result = TaskResult(host, task, dict(unreachable=True))
+            self._host.vars = dict()
+            self._host.groups = []
+            task_result = TaskResult(self._host, self._task, dict(unreachable=True))
             self._rslt_q.put(task_result, block=False)
-                except:
-                    break
+
         except Exception as e:
-                if isinstance(e, (IOError, EOFError, KeyboardInterrupt)) and not isinstance(e, TemplateNotFound):
-                    break
-                else:
+            if not isinstance(e, (IOError, EOFError, KeyboardInterrupt)) or isinstance(e, TemplateNotFound):
                 try:
-                        if task:
-                            task_result = TaskResult(host, task, dict(failed=True, exception=traceback.format_exc(), stdout=''))
+                    self._host.vars = dict()
+                    self._host.groups = []
+                    task_result = TaskResult(self._host, self._task, dict(failed=True, exception=traceback.format_exc(), stdout=''))
                     self._rslt_q.put(task_result, block=False)
                 except:
                     debug("WORKER EXCEPTION: %s" % e)
                     debug("WORKER EXCEPTION: %s" % traceback.format_exc())
-                        break
 
         debug("WORKER PROCESS EXITING")
 
-

lib/ansible/executor/task_queue_manager.py

@@ -102,11 +102,7 @@ class TaskQueueManager:
         for i in xrange(num):
             main_q = multiprocessing.Queue()
             rslt_q = multiprocessing.Queue()
-
-            prc = WorkerProcess(self, main_q, rslt_q, self._hostvars_manager, self._loader)
-            prc.start()
-
-            self._workers.append((prc, main_q, rslt_q))
+            self._workers.append([None, main_q, rslt_q])
 
         self._result_prc = ResultProcess(self._final_q, self._workers)
         self._result_prc.start()
@@ -195,31 +191,12 @@ class TaskQueueManager:
         new_play = play.copy()
         new_play.post_validate(templar)
 
-        class HostVarsManager(SyncManager):
-            pass
-
-        hostvars = HostVars(
+        self.hostvars = HostVars(
             inventory=self._inventory,
             variable_manager=self._variable_manager,
             loader=self._loader,
         )
 
-        HostVarsManager.register(
-            'hostvars',
-            callable=lambda: hostvars,
-            # FIXME: this is the list of exposed methods to the DictProxy object, plus our
-            #        special ones (set_variable_manager/set_inventory). There's probably a better way
-            #        to do this with a proper BaseProxy/DictProxy derivative
-            exposed=(
-                'set_variable_manager', 'set_inventory', '__contains__', '__delitem__',
-                'set_nonpersistent_facts', 'set_host_facts', 'set_host_variable',
-                '__getitem__', '__len__', '__setitem__', 'clear', 'copy', 'get', 'has_key',
-                'items', 'keys', 'pop', 'popitem', 'setdefault', 'update', 'values'
-            ),
-        )
-        self._hostvars_manager = HostVarsManager()
-        self._hostvars_manager.start()
-
         # Fork # of forks, # of hosts or serial, whichever is lowest
         contenders =  [self._options.forks, play.serial, len(self._inventory.get_hosts(new_play.hosts))]
         contenders =  [ v for v in contenders if v is not None and v > 0 ]
@@ -259,7 +236,6 @@ class TaskQueueManager:
         # and run the play using the strategy and cleanup on way out
         play_return = strategy.run(iterator, play_context)
         self._cleanup_processes()
-        self._hostvars_manager.shutdown()
         return play_return
 
     def cleanup(self):
@@ -275,6 +251,7 @@ class TaskQueueManager:
             for (worker_prc, main_q, rslt_q) in self._workers:
                 rslt_q.close()
                 main_q.close()
+                if worker_prc and worker_prc.is_alive():
                     worker_prc.terminate()
 
     def clear_failed_hosts(self):

lib/ansible/plugins/strategy/__init__.py

@@ -31,6 +31,7 @@ from jinja2.exceptions import UndefinedError
 from ansible import constants as C
 from ansible.errors import AnsibleError, AnsibleParserError, AnsibleUndefinedVariable
 from ansible.executor.play_iterator import PlayIterator
+from ansible.executor.process.worker import WorkerProcess
 from ansible.executor.task_result import TaskResult
 from ansible.inventory.host import Host
 from ansible.inventory.group import Group
@@ -138,38 +139,29 @@ class StrategyBase:
 
         display.debug("entering _queue_task() for %s/%s" % (host, task))
 
+        task_vars['hostvars'] = self._tqm.hostvars
         # and then queue the new task
         display.debug("%s - putting task (%s) in queue" % (host, task))
         try:
             display.debug("worker is %d (out of %d available)" % (self._cur_worker+1, len(self._workers)))
 
+            # create a dummy object with plugin loaders set as an easier
+            # way to share them with the forked processes
+            shared_loader_obj = SharedPluginLoaderObj()
+
+            while True:
                 (worker_prc, main_q, rslt_q) = self._workers[self._cur_worker]
+                if worker_prc is None or not worker_prc.is_alive():
+                    worker_prc = WorkerProcess(rslt_q, task_vars, host, task, play_context, self._loader, self._variable_manager, shared_loader_obj)
+                    self._workers[self._cur_worker][0] = worker_prc
+                    worker_prc.start()
+                    break
                 self._cur_worker += 1
                 if self._cur_worker >= len(self._workers):
                     self._cur_worker = 0
+                    time.sleep(0.0001)
 
-            # create a dummy object with plugin loaders set as an easier
-            # way to share them with the forked processes
-            shared_loader_obj = SharedPluginLoaderObj()
-
-            # compress (and convert) the data if so configured, which can
-            # help a lot when the variable dictionary is huge. We pop the
-            # hostvars out of the task variables right now, due to the fact
-            # that they're not JSON serializable
-            compressed_vars = False
-            if C.DEFAULT_VAR_COMPRESSION_LEVEL > 0:
-                zip_vars = zlib.compress(json.dumps(task_vars), C.DEFAULT_VAR_COMPRESSION_LEVEL)
-                compressed_vars = True
-                # we're done with the original dict now, so delete it to
-                # try and reclaim some memory space, which is helpful if the
-                # data contained in the dict is very large
             del task_vars
-            else:
-                zip_vars = task_vars  # noqa (pyflakes false positive because task_vars is deleted in the conditional above)
-
-            # and queue the task
-            main_q.put((host, task, self._loader.get_basedir(), zip_vars, compressed_vars, play_context, shared_loader_obj))
-
             self._pending_results += 1
         except (EOFError, IOError, AssertionError) as e:
             # most likely an abort
@@ -177,7 +169,7 @@ class StrategyBase:
             return
         display.debug("exiting _queue_task() for %s/%s" % (host, task))
 
-    def _process_pending_results(self, iterator):
+    def _process_pending_results(self, iterator, one_pass=False):
         '''
         Reads results off the final queue and takes appropriate action
         based on the result (executing callbacks, updating state, etc.).
@@ -247,13 +239,11 @@ class StrategyBase:
                     new_host_info = result_item.get('add_host', dict())
 
                     self._add_host(new_host_info, iterator)
-                    self._tqm._hostvars_manager.hostvars().set_inventory(self._inventory)
 
                 elif result[0] == 'add_group':
                     host = result[1]
                     result_item = result[2]
                     self._add_group(host, result_item)
-                    self._tqm._hostvars_manager.hostvars().set_inventory(self._inventory)
 
                 elif result[0] == 'notify_handler':
                     task_result  = result[1]
@@ -283,7 +273,6 @@ class StrategyBase:
 
                     for target_host in host_list:
                         self._variable_manager.set_nonpersistent_facts(target_host, {var_name: var_value})
-                        self._tqm._hostvars_manager.hostvars().set_nonpersistent_facts(target_host, {var_name: var_value})
 
                 elif result[0] in ('set_host_var', 'set_host_facts'):
                     host = result[1]
@@ -316,21 +305,22 @@ class StrategyBase:
 
                         for target_host in host_list:
                             self._variable_manager.set_host_variable(target_host, var_name, var_value)
-                            self._tqm._hostvars_manager.hostvars().set_host_variable(target_host, var_name, var_value)
                     elif result[0] == 'set_host_facts':
                         facts = result[4]
                         if task.action == 'set_fact':
                             self._variable_manager.set_nonpersistent_facts(actual_host, facts)
-                            self._tqm._hostvars_manager.hostvars().set_nonpersistent_facts(actual_host, facts)
                         else:
                             self._variable_manager.set_host_facts(actual_host, facts)
-                            self._tqm._hostvars_manager.hostvars().set_host_facts(actual_host, facts)
 
                 else:
                     raise AnsibleError("unknown result message received: %s" % result[0])
+
             except Queue.Empty:
                 time.sleep(0.0001)
 
+            if one_pass:
+                break
+
         return ret_results
 
     def _wait_on_pending_results(self, iterator):

lib/ansible/plugins/strategy/linear.py

@@ -169,6 +169,7 @@ class StrategyModule(StrategyBase):
                 skip_rest   = False
                 choose_step = True
 
+                results = []
                 for (host, task) in host_tasks:
                     if not task:
                         continue
@@ -243,12 +244,14 @@ class StrategyModule(StrategyBase):
                     if run_once:
                         break
 
+                    results += self._process_pending_results(iterator, one_pass=True)
+
                 # go to next host/task group
                 if skip_rest:
                     continue
 
                 display.debug("done queuing things up, now waiting for results queue to drain")
-                results = self._wait_on_pending_results(iterator)
+                results += self._wait_on_pending_results(iterator)
                 host_results.extend(results)
 
                 if not work_to_do and len(iterator.get_failed_hosts()) > 0: