Made uwsgi pids retrieval compatible with psutil>2.0.0

Also added some logging and cleaned code

Change-Id: Icd5f239d346d2e7120ce000dc500cde09228a6b5

stackalytics/processor/main.py

@@ -38,22 +38,20 @@ LOG = logging.getLogger(__name__)
 
 
 def get_pids():
-    uwsgi_dict = {}
+    # needs to be compatible with psutil >= 1.1.1 since it's a global req.
+    PSUTIL2 = psutil.version_info >= (2, 0)
+    result = set([])
     for pid in psutil.get_pid_list():
         try:
             p = psutil.Process(pid)
-            if p.cmdline and p.cmdline[0].find('/uwsgi'):
-                if p.parent:
-                    uwsgi_dict[p.pid] = p.parent.pid
+            name = p.name() if PSUTIL2 else p.name
+            if name == 'uwsgi':
+                LOG.debug('Found uwsgi process, pid: %s', pid)
+                result.add(pid)
         except Exception as e:
             LOG.debug('Exception while iterating process list: %s', e)
             pass
 
-    result = set()
-    for pid in uwsgi_dict:
-        if uwsgi_dict[pid] in uwsgi_dict:
-            result.add(pid)
-
     return result
 
 

stackalytics/processor/runtime_storage.py

@@ -162,6 +162,7 @@ class MemcachedStorage(RuntimeStorage):
         stored_pids = self.memcached.get('pids') or set()
         for pid in stored_pids:
             if pid not in pids:
+                LOG.debug('Purge dead uwsgi pid %s from pids list', pid)
                 self.memcached.delete('pid:%s' % pid)
 
         self.memcached.set('pids', pids)
@@ -175,11 +176,15 @@ class MemcachedStorage(RuntimeStorage):
                     min_update = n
 
         first_valid_update = self.memcached.get('first_valid_update') or 0
+        LOG.debug('Purge polled updates from %(first)s to %(min)s',
+                  {'first': first_valid_update, 'min': min_update})
+
         for delete_id_set in utils.make_range(first_valid_update, min_update,
                                               BULK_DELETE_SIZE):
             if not self.memcached.delete_multi(delete_id_set,
                                                key_prefix=UPDATE_ID_PREFIX):
                 raise Exception('Failed to delete from memcache')
+
         self.memcached.set('first_valid_update', min_update)
 
     def _get_update_count(self):