Switch to multiprocessing instead of threading.

manage.py

@@ -3,6 +3,8 @@
 CLI to manage redash.
 """
 import atfork
+import signal
+
 atfork.monkeypatch_os_fork_functions()
 import atfork.stdlib_fixer
 atfork.stdlib_fixer.fix_logging_module()
@@ -28,26 +30,31 @@ def version():
 def runworkers():
     """Starts the re:dash query executors/workers."""
 
-    try:
-        old_workers = data_manager.redis_connection.smembers('workers')
-        data_manager.redis_connection.delete('workers')
-
-        logging.info("Cleaning old workers: %s", old_workers)
-
-        data_manager.start_workers(settings.WORKERS_COUNT)
-        logging.info("Workers started.")
-
-        while True:
-            try:
-                data_manager.refresh_queries()
-                data_manager.report_status()
-            except Exception as e:
-                logging.error("Something went wrong with refreshing queries...")
-                logging.exception(e)
-            time.sleep(60)
-    except KeyboardInterrupt:
-        logging.warning("Exiting; waiting for threads")
+    def stop_handler(signum, frame):
+        logging.warning("Exiting; waiting for workers")
         data_manager.stop_workers()
+        exit()
+
+    signal.signal(signal.SIGTERM, stop_handler)
+    signal.signal(signal.SIGINT, stop_handler)
+
+    old_workers = data_manager.redis_connection.smembers('workers')
+    data_manager.redis_connection.delete('workers')
+
+    logging.info("Cleaning old workers: %s", old_workers)
+
+    data_manager.start_workers(settings.WORKERS_COUNT)
+    logging.info("Workers started.")
+
+    while True:
+        try:
+            data_manager.refresh_queries()
+            data_manager.report_status()
+        except Exception as e:
+            logging.error("Something went wrong with refreshing queries...")
+            logging.exception(e)
+        time.sleep(60)
+
 
 @manager.shell
 def make_shell_context():

redash/data/manager.py

@@ -142,6 +142,7 @@ class Manager(object):
         redis_connection_params = self.redis_connection.connection_pool.connection_kwargs
         self.workers = [worker.Worker(worker_id, self, redis_connection_params)
                         for worker_id in xrange(workers_count)]
+
         for w in self.workers:
             w.start()
 
@@ -149,7 +150,9 @@ class Manager(object):
 
     def stop_workers(self):
         for w in self.workers:
-            w.continue_working = False
+            w.terminate()
+
+        for w in self.workers:
             w.join()
 
     def _save_status(self):

redash/data/worker.py

@@ -3,8 +3,8 @@ Worker implementation to execute incoming queries.
 """
 import json
 import logging
+import multiprocessing
 import os
-import threading
 import uuid
 import datetime
 import time
@@ -209,31 +209,30 @@ class Job(RedisObject):
         return "<Job:%s,priority:%d,status:%d>" % (self.id, self.priority, self.status)
 
 
-class Worker(threading.Thread):
+class Worker(multiprocessing.Process):
     def __init__(self, worker_id, manager, redis_connection_params, sleep_time=0.1):
         self.manager = manager
 
         self.statsd_client = StatsClient(host=settings.STATSD_HOST, port=settings.STATSD_PORT,
                                          prefix=settings.STATSD_PREFIX)
+
         self.redis_connection_params = {k: v for k, v in redis_connection_params.iteritems()
                                         if k in ('host', 'db', 'password', 'port')}
 
+        self.worker_id = None
         self.continue_working = True
         self.sleep_time = sleep_time
         self.child_pid = None
-        self.worker_id = worker_id
+        self.current_job_id = None
         self.status = {
-            'id': self.worker_id,
             'jobs_count': 0,
             'cancelled_jobs_count': 0,
             'done_jobs_count': 0,
             'updated_at': time.time(),
             'started_at': time.time()
         }
-        self._save_status()
-        self.manager.redis_connection.sadd('workers', self._key)
 
-        super(Worker, self).__init__(name="Worker-%s" % self.worker_id)
+        super(Worker, self).__init__(name="Worker")
 
     def set_title(self, title=None):
         base_title = "redash worker:%s" % self.worker_id
@@ -245,7 +244,28 @@ class Worker(threading.Thread):
         setproctitle.setproctitle(full_title)
 
     def run(self):
+        self.worker_id = os.getpid()
+        self.status['id'] = self.worker_id
+        self.name = "Worker:%d" % self.worker_id
+        self.manager.redis_connection.sadd('workers', self._key)
+        self._save_status()
+        self.set_title()
+
         logging.info("[%s] started.", self.name)
+
+        signal.signal(signal.SIGINT, self._stop)
+        signal.signal(signal.SIGTERM, self._stop)
+
+        self._wait_for_jobs()
+
+    def _stop(self, signum, frame):
+        self.continue_working = False
+        if self.current_job_id:
+            job = Job.load(self.manager.redis_connection, self.current_job_id)
+            if job:
+                job.cancel()
+
+    def _wait_for_jobs(self):
         while self.continue_working:
             job_id = self.manager.queue.pop()
             if job_id:
@@ -270,6 +290,7 @@ class Worker(threading.Thread):
         self.manager.redis_connection.hmset(self._key, self.status)
 
     def _fork_and_process(self, job_id):
+        self.current_job_id = job_id
         self.child_pid = os.fork()
         if self.child_pid == 0:
             self.set_title("processing %s" % job_id)
@@ -291,6 +312,9 @@ class Worker(threading.Thread):
             logging.info("[%s] Finished Processing %s (pid: %d status: %d)",
                          self.name, job_id, self.child_pid, status)
 
+            self.child_pid = None
+            self.current_job_id = None
+
     def _process(self, job_id):
         redis_connection = redis.StrictRedis(**self.redis_connection_params)
         job = Job.load(redis_connection, job_id)