swift: avoid Connection aborted

This change removes usage of threads with swift driver.

This avoids to get "Connection aborted" because a thread is stuck
and the server side decide to break the connection.

Related-bug: gnocchixyz#509
(cherry picked from commit bc18ebd)

gnocchi/incoming/__init__.py

@@ -43,6 +43,9 @@ class IncomingDriver(object):
     SACK_PREFIX = "incoming"
     CFG_PREFIX = 'gnocchi-config'
     CFG_SACKS = 'sacks'
+    # NOTE(sileht): By default we use threads, but some driver can disable
+    # threads by setting this to utils.sequencial_map
+    MAP_METHOD = staticmethod(utils.parallel_map)
 
     @property
     def NUM_SACKS(self):
@@ -122,11 +125,10 @@ def add_measures_batch(self, metrics_and_measures):
                                      and values are a list of
                                      :py:class:`gnocchi.incoming.Measure`.
         """
-        utils.parallel_map(
-            self._store_new_measures,
-            ((metric_id, self._encode_measures(measures))
-             for metric_id, measures
-             in six.iteritems(metrics_and_measures)))
+        self.MAP_METHOD(self._store_new_measures,
+                        ((metric_id, self._encode_measures(measures))
+                         for metric_id, measures
+                         in six.iteritems(metrics_and_measures)))
 
     @staticmethod
     def _store_new_measures(metric_id, data):

gnocchi/incoming/swift.py

@@ -21,12 +21,17 @@
 
 from gnocchi.common import swift
 from gnocchi import incoming
+from gnocchi import utils
 
 swclient = swift.swclient
 swift_utils = swift.swift_utils
 
 
 class SwiftStorage(incoming.IncomingDriver):
+    # NOTE(sileht): Using threads with swiftclient doesn't work
+    # as expected, so disable it
+    MAP_METHOD = staticmethod(utils.sequencial_map)
+
     def __init__(self, conf, greedy=True):
         super(SwiftStorage, self).__init__(conf)
         self.swift = swift.get_connection(conf)

gnocchi/storage/__init__.py

@@ -119,6 +119,10 @@ def get_driver(conf, coord):
 
 class StorageDriver(object):
 
+    # NOTE(sileht): By default we use threads, but some driver can disable
+    # threads by setting this to utils.sequencial_map
+    MAP_METHOD = staticmethod(utils.parallel_map)
+
     def __init__(self, conf, coord):
         self.coord = coord
 
@@ -127,7 +131,7 @@ def upgrade():
         pass
 
     def _get_measures(self, metric, keys, aggregation, version=3):
-        return utils.parallel_map(
+        return self.MAP_METHOD(
             self._get_measures_unbatched,
             ((metric, key, aggregation, version)
              for key in keys))
@@ -217,7 +221,7 @@ def get_measures(self, metric, granularities,
                 raise AggregationDoesNotExist(metric, aggregation, g)
             aggregations.append(agg)
 
-        agg_timeseries = utils.parallel_map(
+        agg_timeseries = self.MAP_METHOD(
             self._get_measures_timeserie,
             ((metric, ag, from_timestamp, to_timestamp)
              for ag in aggregations))
@@ -568,7 +572,7 @@ def _map_add_measures(bound_timeserie):
                     d.granularity, carbonara.round_timestamp(
                         tstamp, d.granularity))
 
-                utils.parallel_map(
+                self.MAP_METHOD(
                     self._add_measures,
                     ((aggregation, d, metric, ts,
                         current_first_block_timestamp,

gnocchi/storage/swift.py

@@ -82,6 +82,9 @@
 class SwiftStorage(storage.StorageDriver):
 
     WRITE_FULL = True
+    # NOTE(sileht): Using threads with swiftclient doesn't work
+    # as expected, so disable it
+    MAP_METHOD = staticmethod(utils.sequencial_map)
 
     def __init__(self, conf, coord=None):
         super(SwiftStorage, self).__init__(conf, coord)

gnocchi/utils.py

@@ -299,11 +299,15 @@ def get_driver_class(namespace, conf):
                                 conf.driver).driver
 
 
+def sequencial_map(fn, list_of_args):
+    return list(itertools.starmap(fn, list_of_args))
+
+
 def parallel_map(fn, list_of_args):
     """Run a function in parallel."""
 
     if parallel_map.MAX_WORKERS == 1:
-        return list(itertools.starmap(fn, list_of_args))
+        return sequencial_map(fn, list_of_args)
 
     with futures.ThreadPoolExecutor(
             max_workers=parallel_map.MAX_WORKERS) as executor: