ec: Close down some unused responses more quickly

These should get GC'ed eventually, but sooner is probably better than later.

Change-Id: I4daa18c36235e6df65e8b1c00a12dbf10677ca61

swift/proxy/controllers/obj.py

@@ -2087,6 +2087,14 @@ class ECGetResponseBucket(object):
         result = self.policy.ec_ndata - (len(self.get_responses()) + len(alts))
         return max(result, 0)
 
+    def close_conns(self):
+        """
+        Close bucket's responses; they won't be used for a client response.
+        """
+        for getter, frag_iter in self.get_responses():
+            if getattr(getter.source, 'swift_conn', None):
+                close_swift_conn(getter.source)
+
     def __str__(self):
         # return a string summarising bucket state, useful for debugging.
         return '<%s, %s, %s, %s(%s), %s>' \
@@ -2227,6 +2235,15 @@ class ECGetResponseCollection(object):
             return bucket
         return self.least_bad_bucket
 
+    def choose_best_bucket(self):
+        best_bucket = self.best_bucket
+        # it's now or never -- close down any other requests
+        for bucket in self.buckets.values():
+            if bucket is best_bucket:
+                continue
+            bucket.close_conns()
+        return best_bucket
+
     @property
     def least_bad_bucket(self):
         """
@@ -2343,6 +2360,7 @@ class ECFragGetter(object):
         self.client_chunk_size = policy.fragment_size
         self.skip_bytes = 0
         self.bytes_used_from_backend = 0
+        self.source = None
 
     def fast_forward(self, num_bytes):
         """
@@ -2452,19 +2470,15 @@ class ECFragGetter(object):
 
     def response_parts_iter(self, req):
         try:
-            source, node = next(self.source_and_node_iter)
+            self.source, self.node = next(self.source_and_node_iter)
         except StopIteration:
             return
         it = None
-        if source:
-            it = self._get_response_parts_iter(req, node, source)
+        if self.source:
+            it = self._get_response_parts_iter(req)
         return it
 
-    def _get_response_parts_iter(self, req, node, source):
-        # Someday we can replace this [mess] with python 3's "nonlocal"
-        source = [source]
-        node = [node]
-
+    def _get_response_parts_iter(self, req):
         try:
             client_chunk_size = self.client_chunk_size
             node_timeout = self.app.recoverable_node_timeout
@@ -2473,7 +2487,7 @@ class ECFragGetter(object):
             # on it, so no IO is performed.
             parts_iter = [
                 http_response_to_document_iters(
-                    source[0], read_chunk_size=self.app.object_chunk_size)]
+                    self.source, read_chunk_size=self.app.object_chunk_size)]
 
             def get_next_doc_part():
                 while True:
@@ -2497,13 +2511,13 @@ class ECFragGetter(object):
                         new_source, new_node = self._dig_for_source_and_node()
                         if new_source:
                             self.app.error_occurred(
-                                node[0], _('Trying to read object during '
-                                           'GET (retrying)'))
+                                self.node, _('Trying to read object during '
+                                             'GET (retrying)'))
                             # Close-out the connection as best as possible.
-                            if getattr(source[0], 'swift_conn', None):
-                                close_swift_conn(source[0])
-                            source[0] = new_source
-                            node[0] = new_node
+                            if getattr(self.source, 'swift_conn', None):
+                                close_swift_conn(self.source)
+                            self.source = new_source
+                            self.node = new_node
                             # This is safe; it sets up a generator but does
                             # not call next() on it, so no IO is performed.
                             parts_iter[0] = http_response_to_document_iters(
@@ -2539,13 +2553,13 @@ class ECFragGetter(object):
                         new_source, new_node = self._dig_for_source_and_node()
                         if new_source:
                             self.app.error_occurred(
-                                node[0], _('Trying to read object during '
-                                           'GET (retrying)'))
+                                self.node, _('Trying to read object during '
+                                             'GET (retrying)'))
                             # Close-out the connection as best as possible.
-                            if getattr(source[0], 'swift_conn', None):
-                                close_swift_conn(source[0])
-                            source[0] = new_source
-                            node[0] = new_node
+                            if getattr(self.source, 'swift_conn', None):
+                                close_swift_conn(self.source)
+                            self.source = new_source
+                            self.node = new_node
                             # This is safe; it just sets up a generator but
                             # does not call next() on it, so no IO is
                             # performed.
@@ -2650,7 +2664,7 @@ class ECFragGetter(object):
                     part_iter.close()
 
         except ChunkReadTimeout:
-            self.app.exception_occurred(node[0], _('Object'),
+            self.app.exception_occurred(self.node, _('Object'),
                                         _('Trying to read during GET'))
             raise
         except ChunkWriteTimeout:
@@ -2677,8 +2691,8 @@ class ECFragGetter(object):
             raise
         finally:
             # Close-out the connection as best as possible.
-            if getattr(source[0], 'swift_conn', None):
-                close_swift_conn(source[0])
+            if getattr(self.source, 'swift_conn', None):
+                close_swift_conn(self.source)
 
     @property
     def last_status(self):
@@ -2727,6 +2741,7 @@ class ECFragGetter(object):
                 not Timestamp(src_headers.get('x-backend-timestamp', 0)):
             # throw out 5XX and 404s from handoff nodes unless the data is
             # really on disk and had been DELETEd
+            conn.close()
             return None
 
         self.status = possible_source.status
@@ -2737,6 +2752,7 @@ class ECFragGetter(object):
             return possible_source
         else:
             self.body = possible_source.read()
+            conn.close()
 
             if possible_source.status == HTTP_INSUFFICIENT_STORAGE:
                 self.app.error_limit(node, _('ERROR Insufficient Storage'))
@@ -2939,7 +2955,7 @@ class ECObjectController(BaseObjectController):
         # Put this back, since we *may* need it for kickoff()/_fix_response()
         # (but note that _fix_ranges() may also pop it back off before then)
         req.range = orig_range
-        best_bucket = buckets.best_bucket
+        best_bucket = buckets.choose_best_bucket()
         if best_bucket.shortfall <= 0 and best_bucket.durable:
             # headers can come from any of the getters
             resp_headers = best_bucket.headers
@@ -2979,6 +2995,7 @@ class ECObjectController(BaseObjectController):
             reasons = []
             bodies = []
             headers = []
+            best_bucket.close_conns()
             for status, bad_bucket in buckets.bad_buckets.items():
                 for getter, _parts_iter in bad_bucket.get_responses():
                     if best_bucket.durable:

test/unit/__init__.py

@@ -1029,6 +1029,10 @@ def fake_http_connect(*code_iter, **kwargs):
         def getheader(self, name, default=None):
             return HeaderKeyDict(self.getheaders()).get(name, default)
 
+        def nuke_from_orbit(self):
+            # wrapped connections from buffered_http have this helper
+            self.close()
+
         def close(self):
             self.closed = True
 
@@ -1091,10 +1095,13 @@ def fake_http_connect(*code_iter, **kwargs):
             body = static_body or b''
         else:
             body = next(body_iter)
-        return FakeConn(status, etag, body=body, timestamp=timestamp,
+        conn = FakeConn(status, etag, body=body, timestamp=timestamp,
                         headers=headers, expect_headers=expect_headers,
                         connection_id=i, give_send=kwargs.get('give_send'),
                         give_expect=kwargs.get('give_expect'))
+        if 'capture_connections' in kwargs:
+            kwargs['capture_connections'].append(conn)
+        return conn
 
     connect.unexpected_requests = unexpected_requests
     connect.code_iter = code_iter
@@ -1105,6 +1112,7 @@ def fake_http_connect(*code_iter, **kwargs):
 @contextmanager
 def mocked_http_conn(*args, **kwargs):
     requests = []
+    responses = []
 
     def capture_requests(ip, port, method, path, headers, qs, ssl):
         if six.PY2 and not isinstance(ip, bytes):
@@ -1120,8 +1128,10 @@ def mocked_http_conn(*args, **kwargs):
         }
         requests.append(req)
     kwargs.setdefault('give_connect', capture_requests)
+    kwargs['capture_connections'] = responses
     fake_conn = fake_http_connect(*args, **kwargs)
     fake_conn.requests = requests
+    fake_conn.responses = responses
     with mocklib.patch('swift.common.bufferedhttp.http_connect_raw',
                        new=fake_conn):
         yield fake_conn
@@ -1185,6 +1195,10 @@ class StubResponse(object):
         fake_reason = ('Fake', 'This response is a lie.')
         self.reason = swob.RESPONSE_REASONS.get(status, fake_reason)[0]
 
+    def nuke_from_orbit(self):
+        if hasattr(self, 'swift_conn'):
+            self.swift_conn.close()
+
     def getheader(self, header_name, default=None):
         return self.headers.get(header_name, default)
 

test/unit/proxy/controllers/test_obj.py

@@ -2061,6 +2061,7 @@ def capture_http_requests(get_response):
             self.req = req
             self.resp = None
             self.path = "/"
+            self.closed = False
 
         def getresponse(self):
             self.resp = get_response(self.req)
@@ -2075,6 +2076,9 @@ def capture_http_requests(get_response):
         def endheaders(self):
             pass
 
+        def close(self):
+            self.closed = True
+
     class ConnectionLog(object):
 
         def __init__(self):
@@ -2826,7 +2830,16 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
 
         self.assertEqual(resp.status_int, 200)
         self.assertEqual(resp.headers['etag'], obj2['etag'])
+        closed_conn = defaultdict(set)
+        for conn in log:
+            etag = conn.resp.headers['X-Object-Sysmeta-Ec-Etag']
+            closed_conn[etag].add(conn.closed)
+        self.assertEqual({
+            obj1['etag']: {True},
+            obj2['etag']: {False},
+        }, closed_conn)
         self.assertEqual(md5(resp.body).hexdigest(), obj2['etag'])
+        self.assertEqual({True}, {conn.closed for conn in log})
 
         collected_responses = defaultdict(set)
         for conn in log:
@@ -2999,6 +3012,15 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
         with capture_http_requests(fake_response) as log:
             resp = req.get_response(self.app)
 
+        closed_conn = defaultdict(set)
+        for conn in log:
+            etag = conn.resp.headers.get('X-Object-Sysmeta-Ec-Etag')
+            closed_conn[etag].add(conn.closed)
+        self.assertEqual({
+            obj1['etag']: {True},
+            obj2['etag']: {True},
+            None: {True},
+        }, dict(closed_conn))
         self.assertEqual(resp.status_int, 503)
 
         collected_responses = defaultdict(set)
@@ -3148,10 +3170,12 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
 
         collected_etags = set()
         collected_status = set()
+        closed_conn = defaultdict(set)
         for conn in log:
             etag = conn.resp.headers['X-Object-Sysmeta-Ec-Etag']
             collected_etags.add(etag)
             collected_status.add(conn.resp.status)
+            closed_conn[etag].add(conn.closed)
 
         # default node_iter will exhaust at 2 * replicas
         self.assertEqual(len(log), 2 * self.replicas())
@@ -3159,6 +3183,12 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
             {obj1['etag'], obj2['etag'], obj3['etag'], obj4['etag']},
             collected_etags)
         self.assertEqual({200}, collected_status)
+        self.assertEqual({
+            obj1['etag']: {True},
+            obj2['etag']: {True},
+            obj3['etag']: {True},
+            obj4['etag']: {True},
+        }, closed_conn)
 
     def test_GET_with_mixed_durable_and_nondurable_frags_will_503(self):
         # all nodes have a frag but there is no one set that reaches quorum,
@@ -3208,12 +3238,14 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
 
         self.assertEqual(resp.status_int, 503)
 
+        closed_conn = defaultdict(set)
         collected_etags = set()
         collected_status = set()
         for conn in log:
             etag = conn.resp.headers['X-Object-Sysmeta-Ec-Etag']
             collected_etags.add(etag)
             collected_status.add(conn.resp.status)
+            closed_conn[etag].add(conn.closed)
 
         # default node_iter will exhaust at 2 * replicas
         self.assertEqual(len(log), 2 * self.replicas())
@@ -3221,6 +3253,12 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
             {obj1['etag'], obj2['etag'], obj3['etag'], obj4['etag']},
             collected_etags)
         self.assertEqual({200}, collected_status)
+        self.assertEqual({
+            obj1['etag']: {True},
+            obj2['etag']: {True},
+            obj3['etag']: {True},
+            obj4['etag']: {True},
+        }, closed_conn)
 
     def test_GET_with_mixed_durable_frags_and_no_quorum_will_503(self):
         # all nodes have a frag but there is no one set that reaches quorum,
@@ -3270,12 +3308,17 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
 
         self.assertEqual(resp.status_int, 503)
 
+        for conn in log:
+            etag = conn.resp.headers.get('X-Object-Sysmeta-Ec-Etag')
+
         collected_etags = set()
         collected_status = set()
+        closed_conn = defaultdict(set)
         for conn in log:
             etag = conn.resp.headers['X-Object-Sysmeta-Ec-Etag']
             collected_etags.add(etag)
             collected_status.add(conn.resp.status)
+            closed_conn[etag].add(conn.closed)
 
         # default node_iter will exhaust at 2 * replicas
         self.assertEqual(len(log), 2 * self.replicas())
@@ -3283,6 +3326,12 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
             {obj1['etag'], obj2['etag'], obj3['etag'], obj4['etag']},
             collected_etags)
         self.assertEqual({200}, collected_status)
+        self.assertEqual({
+            obj1['etag']: {True},
+            obj2['etag']: {True},
+            obj3['etag']: {True},
+            obj4['etag']: {True},
+        }, closed_conn)
 
     def test_GET_with_quorum_durable_files(self):
         # verify that only (ec_nparity + 1) nodes need to be durable for a GET
@@ -3436,9 +3485,18 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
         fake_response = self._fake_ec_node_response(list(node_frags))
 
         req = swob.Request.blank('/v1/a/c/o')
-        with capture_http_requests(fake_response):
+        with capture_http_requests(fake_response) as log:
             resp = req.get_response(self.app)
 
+        closed_conn = defaultdict(set)
+        for conn in log:
+            etag = conn.resp.headers.get('X-Object-Sysmeta-Ec-Etag')
+            closed_conn[etag].add(conn.closed)
+        self.assertEqual({
+            obj1['etag']: {False},
+            obj2['etag']: {True},
+        }, closed_conn)
+
         self.assertEqual(resp.status_int, 200)
         self.assertEqual(resp.headers['etag'], obj1['etag'])
         self.assertEqual(md5(resp.body).hexdigest(), obj1['etag'])
@@ -3530,6 +3588,15 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
         with capture_http_requests(fake_response) as log:
             resp = req.get_response(self.app)
 
+        closed_conn = defaultdict(set)
+        for conn in log:
+            etag = conn.resp.headers.get('X-Object-Sysmeta-Ec-Etag')
+            closed_conn[etag].add(conn.closed)
+        self.assertEqual({
+            obj1['etag']: {True},
+            obj2['etag']: {False},
+        }, closed_conn)
+
         self.assertEqual(resp.status_int, 200)
         self.assertEqual(resp.headers['etag'], obj2['etag'])
         self.assertEqual(md5(resp.body).hexdigest(), obj2['etag'])
@@ -3922,6 +3989,16 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
         with capture_http_requests(get_response) as log:
             resp = req.get_response(self.app)
 
+        closed_conn = defaultdict(set)
+        for conn in log:
+            etag = conn.resp.headers.get('X-Object-Sysmeta-Ec-Etag')
+            closed_conn[etag].add(conn.closed)
+        self.assertEqual({
+            old_etag: {True},
+            new_etag: {False},
+            None: {True},
+        }, dict(closed_conn))
+
         self.assertEqual(resp.status_int, 200)
         self.assertEqual(resp.body, new_data[:segment_size])
         self.assertEqual(len(log), self.policy.ec_ndata + 10)
@@ -4134,8 +4211,8 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
         self.app.recoverable_node_timeout = 0.01
         req = swob.Request.blank('/v1/a/c/o')
         status_codes, body_iter, headers = zip(*responses)
-        with set_http_connect(*status_codes, body_iter=body_iter,
-                              headers=headers):
+        with mocked_http_conn(*status_codes, body_iter=body_iter,
+                              headers=headers) as log:
             resp = req.get_response(self.app)
             self.assertEqual(resp.status_int, 200)
             self.assertEqual(md5(resp.body).hexdigest(), etag1)
@@ -4143,6 +4220,13 @@ class TestECObjController(ECObjectControllerMixin, unittest.TestCase):
         self.assertEqual(2, len(error_lines))
         for line in error_lines:
             self.assertIn('retrying', line)
+        etag2_conns = []
+        for conn in log.responses:
+            if conn.headers.get('X-Object-Sysmeta-Ec-Etag') == etag2:
+                etag2_conns.append(conn)
+        self.assertEqual(
+            ([True] * 8) + [False],  # the resumed etag2 doesn't get closed
+            [conn.closed for conn in etag2_conns])
 
     def test_fix_response_HEAD(self):
         headers = {'X-Object-Sysmeta-Ec-Content-Length': '10',