Merge pull request #41 from Koed00/dev

Workaround for osx implementation

django_q/cluster.py

@@ -22,12 +22,6 @@ from multiprocessing import Queue, Event, Process, Value, current_process
 # external
 import arrow
 
-# optional
-try:
-    import psutil
-except ImportError:
-    psutil = None
-
 # Django
 from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
@@ -37,7 +31,7 @@ from django import db
 import signing
 import tasks
 
-from django_q.conf import Conf, redis_client, logger
+from django_q.conf import Conf, redis_client, logger, psutil
 from django_q.models import Task, Success, Schedule
 from django_q.monitor import Status, Stat
 
@@ -149,7 +143,7 @@ class Sentinel(object):
         if not self.start_event.is_set() and not self.stop_event.is_set():
             return Conf.STARTING
         elif self.start_event.is_set() and not self.stop_event.is_set():
-            if self.result_queue.qsize() == 0 and self.task_queue.qsize() == 0:
+            if Conf.QSIZE and self.result_queue.qsize() == 0 and self.task_queue.qsize() == 0:
                 return Conf.IDLE
             return Conf.WORKING
         elif self.stop_event.is_set() and self.start_event.is_set():

django_q/conf.py

@@ -1,11 +1,20 @@
 import logging
 from signal import signal
-from multiprocessing import cpu_count
+from multiprocessing import cpu_count, Queue
 
+# django
 from django.utils.translation import ugettext_lazy as _
 from django.conf import settings
+
+# external
 import redis
 
+# optional
+try:
+    import psutil
+except ImportError:
+    psutil = None
+
 
 class Conf(object):
     """
@@ -36,8 +45,19 @@ class Conf(object):
     # Maximum number of tasks that each cluster can work on
     QUEUE_LIMIT = conf.get('queue_limit', None)
 
-    # Number of workers in the pool. Default is cpu count. +2 for monitor and pusher
-    WORKERS = conf.get('workers', cpu_count())
+    # Number of workers in the pool. Default is cpu count if implemented, otherwise 4.
+    WORKERS = conf.get('workers', False)
+    if not WORKERS:
+        try:
+            WORKERS = cpu_count()
+            # in rare cases this might fail
+        except NotImplementedError:
+            # try psutil
+            if psutil:
+                WORKERS = psutil.cpu_count() or 4
+            else:
+                # sensible default
+                WORKERS = 4
 
     # Sets compression of redis packages
     COMPRESSED = conf.get('compress', False)
@@ -63,6 +83,12 @@ class Conf(object):
     # The redis stats key
     Q_STAT = 'django_q:{}:cluster'.format(PREFIX)
 
+    # OSX doesn't implement qsize because of missing sem_getvalue()
+    try:
+        QSIZE = Queue().qsize() == 0
+    except NotImplementedError:
+        QSIZE = False
+
     # Getting the signal names
     SIGNAL_NAMES = dict((getattr(signal, n), n) for n in dir(signal) if n.startswith('SIG') and '_' not in n)
 

django_q/monitor.py

@@ -117,10 +117,13 @@ class Stat(Status):
         self.reincarnations = sentinel.reincarnations
         self.sentinel = sentinel.pid
         self.status = sentinel.status()
-        self.done_q_size = sentinel.result_queue.qsize()
+        self.done_q_size = 0
+        self.task_q_size = 0
+        if Conf.QSIZE:
+            self.done_q_size = sentinel.result_queue.qsize()
+            self.task_q_size = sentinel.task_queue.qsize()
         if sentinel.monitor:
             self.monitor = sentinel.monitor.pid
-        self.task_q_size = sentinel.task_queue.qsize()
         if sentinel.pusher:
             self.pusher = sentinel.pusher.pid
         self.workers = [w.pid for w in sentinel.pool]

django_q/tests/test_cluster.py

@@ -55,7 +55,8 @@ def test_cluster_initial(r):
     assert c.is_starting is False
     sleep(0.5)
     stat = c.stat
-    assert stat.status == Conf.IDLE
+    if Conf.QSIZE:
+        assert stat.status == Conf.IDLE
     assert c.stop() is True
     assert c.sentinel.is_alive() is False
     assert c.has_stopped

docs/install.rst

@@ -59,7 +59,7 @@ This can be useful if you have several projects using the same Redis server.
 workers
 ~~~~~~~
 
-The number of workers to use in the cluster. Defaults to CPU count of the current host, but can be set to a custom number.
+The number of workers to use in the cluster. Defaults to CPU count of the current host, but can be set to a custom number.  [#f1]_
 
 recycle
 ~~~~~~~
@@ -232,4 +232,8 @@ Optional
     $ pip install hiredis
 
 
-.. py:module:: django_q
+.. py:module:: django_q
+
+.. rubric:: Footnotes
+
+.. [#f1] Uses :func:`multiprocessing.cpu_count()` which can fail on some platforms. If so , please set the worker count in the configuration manually or install :ref:`psutil<psutil>` to provide an alternative cpu count method.

docs/monitor.rst

@@ -30,7 +30,7 @@ State
 Current state of the cluster:
 
 - **Starting** The cluster is spawning workers and getting ready.
-- **Idle** Everything is ok, but there are no tasks to process.
+- **Idle** Everything is ok, but there are no tasks to process. [#f1]_
 - **Working** Processing tasks like a good cluster should.
 - **Stopping** The cluster does not take on any new tasks and is finishing.
 - **Stopped** All tasks have been processed and the cluster is shutting down.
@@ -43,7 +43,7 @@ The current number of workers in the cluster pool.
 TQ
 ~~
 
-**Task Queue** counts the number of tasks in the queue
+**Task Queue** counts the number of tasks in the queue [#f1]_
 
 If this keeps rising it means you are taking on more tasks than your cluster can handle.
 You can limit this by settings the :ref:`queue_limit` in your cluster configuration, after which it will turn green when that limit has been reached.
@@ -52,7 +52,7 @@ If your task queue is always hitting its limit and your running out of resources
 RQ
 ~~
 
-**Result Queue** shows the number of results in the queue.
+**Result Queue** shows the number of results in the queue. [#f1]_
 
 Since results are only saved by a single process which has to access the database.
 It's normal for the result queue to take slightly longer to clear than the task queue.
@@ -118,11 +118,11 @@ Reference
 
     .. py:attribute:: task_q_size
 
-    The number of tasks currently in the task queue.
+    The number of tasks currently in the task queue. [#f1]_
 
     .. py:attribute:: done_q_size
 
-    The number of tasks currently in the result queue.
+    The number of tasks currently in the result queue. [#f1]_
 
     .. py:attribute:: pusher
 
@@ -151,3 +151,7 @@ Reference
     .. py:classmethod:: get_all(r=redis_client)
 
     Returns a list of :class:`Stat` objects for all active clusters. Takes an optional redis connection.
+
+.. rubric:: Footnotes
+
+.. [#f1] Uses :meth:`multiprocessing.Queue.qsize()` which is not implemented on OS X.