diff --git a/etc/object-server.conf-sample b/etc/object-server.conf-sample
index 545554ddd3..6a69058f86 100644
--- a/etc/object-server.conf-sample
+++ b/etc/object-server.conf-sample
@@ -390,6 +390,39 @@ use = egg:swift#recon
 # the environment (default). For more information, see
 # https://bugs.launchpad.net/liberasurecode/+bug/1886088
 # write_legacy_ec_crc =
+#
+# When attempting to reconstruct a missing fragment on another node from a
+# fragment on the local node, the reconstructor may fail to fetch sufficient
+# fragments to reconstruct the missing fragment. This may be because most or
+# all of the remote fragments have been deleted, and the local fragment is
+# stale, in which case the reconstructor will never succeed in reconstructing
+# the apparently missing fragment and will log errors. If the object's
+# tombstones have been reclaimed then the stale fragment will never be deleted
+# (see https://bugs.launchpad.net/swift/+bug/1655608). If an operator suspects
+# that stale fragments have been re-introduced to the cluster and is seeing
+# error logs similar to those in the bug report, then the quarantine_threshold
+# option may be set to a value greater than zero. This enables the
+# reconstructor to quarantine the stale fragments when it fails to fetch more
+# than the quarantine_threshold number of fragments (including the stale
+# fragment) during an attempt to reconstruct. For example, setting the
+# quarantine_threshold to 1 would cause a fragment to be quarantined if no
+# other fragments can be fetched. The value may be reset to zero after the
+# reconstructor has run on all affected nodes and the error logs are no longer
+# seen.
+# Note: the quarantine_threshold applies equally to all policies, but for each
+# policy it is effectively capped at (ec_ndata - 1) so that a fragment is never
+# quarantined when sufficient fragments exist to reconstruct the object.
+# Fragments are not quarantined until they are older than the reclaim_age.
+# quarantine_threshold = 0
+#
+# Sets the maximum number of nodes to which requests will be made before
+# quarantining a fragment. You can use '* replicas' at the end to have it use
+# the number given times the number of replicas for the ring being used for the
+# requests. The minimum number of nodes to which requests are made is the
+# number of replicas for the policy minus 1 (the node on which the fragment is
+# to be rebuilt). The minimum is only exceeded if request_node_count is
+# greater, and only for the purposes of quarantining.
+# request_node_count = 2 * replicas
 
 [object-updater]
 # You can override the default log routing for this app here (don't use set!):
diff --git a/etc/proxy-server.conf-sample b/etc/proxy-server.conf-sample
index d0bc1caae7..dea16eb95f 100644
--- a/etc/proxy-server.conf-sample
+++ b/etc/proxy-server.conf-sample
@@ -220,8 +220,8 @@ use = egg:swift#proxy
 # to use up to replica count threads when waiting on a response.  In
 # conjunction with the concurrency_timeout option this will allow swift to send
 # out GET/HEAD requests to the storage nodes concurrently and answer as soon as
-# the minimum number of backend responses are availabe - in replicated contexts
-# this will be the first backend replica to respond.
+# the minimum number of backend responses are available - in replicated
+# contexts this will be the first backend replica to respond.
 # concurrent_gets = off
 #
 # This parameter controls how long to wait before firing off the next
diff --git a/swift/common/utils.py b/swift/common/utils.py
index ad157e58ab..404d384c9d 100644
--- a/swift/common/utils.py
+++ b/swift/common/utils.py
@@ -515,6 +515,23 @@ def config_percent_value(value):
         raise ValueError("%s: %s" % (str(err), value))
 
 
+def config_request_node_count_value(value):
+    try:
+        value_parts = value.lower().split()
+        rnc_value = int(value_parts[0])
+    except (ValueError, AttributeError):
+        pass
+    else:
+        if len(value_parts) == 1:
+            return lambda replicas: rnc_value
+        elif (len(value_parts) == 3 and
+              value_parts[1] == '*' and
+              value_parts[2] == 'replicas'):
+            return lambda replicas: rnc_value * replicas
+    raise ValueError(
+        'Invalid request_node_count value: %r' % value)
+
+
 def append_underscore(prefix):
     if prefix and not prefix.endswith('_'):
         prefix += '_'
diff --git a/swift/obj/reconstructor.py b/swift/obj/reconstructor.py
index de29903245..5d73ba00dd 100644
--- a/swift/obj/reconstructor.py
+++ b/swift/obj/reconstructor.py
@@ -12,7 +12,7 @@
 # implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import itertools
 import json
 import errno
 import os
@@ -33,7 +33,8 @@ from swift.common.utils import (
     dump_recon_cache, mkdirs, config_true_value,
     GreenAsyncPile, Timestamp, remove_file,
     load_recon_cache, parse_override_options, distribute_evenly,
-    PrefixLoggerAdapter, remove_directory)
+    PrefixLoggerAdapter, remove_directory, config_request_node_count_value,
+    non_negative_int)
 from swift.common.header_key_dict import HeaderKeyDict
 from swift.common.bufferedhttp import http_connect
 from swift.common.daemon import Daemon
@@ -102,8 +103,8 @@ class ResponseBucket(object):
     def __init__(self):
         # count of all responses associated with this Bucket
         self.num_responses = 0
-        # map {frag_index: response} for subset of responses that
-        # could be used to rebuild the missing fragment
+        # map {frag_index: response} for subset of responses that could be used
+        # to rebuild the missing fragment
         self.useful_responses = {}
         # set if a durable timestamp was seen in responses
         self.durable = False
@@ -232,6 +233,10 @@ class ObjectReconstructor(Daemon):
                                 'of handoffs_only.')
         self.rebuild_handoff_node_count = int(conf.get(
             'rebuild_handoff_node_count', 2))
+        self.quarantine_threshold = non_negative_int(
+            conf.get('quarantine_threshold', 0))
+        self.request_node_count = config_request_node_count_value(
+            conf.get('request_node_count', '2 * replicas'))
 
         # When upgrading from liberasurecode<=1.5.0, you may want to continue
         # writing legacy CRCs until all nodes are upgraded and capabale of
@@ -368,23 +373,24 @@ class ObjectReconstructor(Daemon):
                 return False
         return True
 
-    def _get_response(self, node, part, path, headers, full_path):
+    def _get_response(self, node, policy, partition, path, headers):
         """
         Helper method for reconstruction that GETs a single EC fragment
         archive
 
         :param node: the node to GET from
-        :param part: the partition
+        :param policy: the job policy
+        :param partition: the partition
         :param path: path of the desired EC archive relative to partition dir
         :param headers: the headers to send
-        :param full_path: full path to desired EC archive
         :returns: response
         """
+        full_path = _full_path(node, partition, path, policy)
         resp = None
         try:
             with ConnectionTimeout(self.conn_timeout):
                 conn = http_connect(node['ip'], node['port'], node['device'],
-                                    part, 'GET', path, headers=headers)
+                                    partition, 'GET', path, headers=headers)
             with Timeout(self.node_timeout):
                 resp = conn.getresponse()
                 resp.full_path = full_path
@@ -462,7 +468,11 @@ class ObjectReconstructor(Daemon):
                               fi_to_rebuild)
             return None
 
-        if fi_to_rebuild == resp_frag_index:
+        durable_timestamp = resp.headers.get('X-Backend-Durable-Timestamp')
+        if durable_timestamp:
+            buckets[Timestamp(durable_timestamp)].durable = True
+
+        if resp_frag_index == fi_to_rebuild:
             # TODO: With duplicated EC frags it's not unreasonable to find the
             # very fragment we're trying to rebuild exists on another primary
             # node.  In this case we should stream it directly from the remote
@@ -471,19 +481,43 @@ class ObjectReconstructor(Daemon):
                 'Found existing frag #%s at %s while rebuilding to %s',
                 fi_to_rebuild, resp.full_path,
                 _full_path(node, partition, path, policy))
-            return None
-
-        durable_timestamp = resp.headers.get('X-Backend-Durable-Timestamp')
-        if durable_timestamp:
-            buckets[Timestamp(durable_timestamp)].durable = True
-
-        if resp_frag_index not in bucket.useful_responses:
+        elif resp_frag_index not in bucket.useful_responses:
             bucket.useful_responses[resp_frag_index] = resp
-            return bucket
-        return None
+        # else: duplicate frag_index isn't useful for rebuilding
 
-    def _make_fragment_requests(self, job, node, datafile_metadata, buckets,
-                                error_responses, nodes):
+        return bucket
+
+    def _is_quarantine_candidate(self, policy, buckets, error_responses, df):
+        # This condition is deliberately strict because it determines if
+        # more requests will be issued and ultimately if the fragment
+        # will be quarantined.
+        if list(error_responses.keys()) != [404]:
+            # only quarantine if all other responses are 404 so we are
+            # confident there are no other frags on queried nodes
+            return False
+
+        local_timestamp = Timestamp(df.get_datafile_metadata()['X-Timestamp'])
+        if list(buckets.keys()) != [local_timestamp]:
+            # don't quarantine if there's insufficient other timestamp
+            # frags, or no response for the local frag timestamp: we
+            # possibly could quarantine, but this unexpected case may be
+            # worth more investigation
+            return False
+
+        if time.time() - float(local_timestamp) <= df.manager.reclaim_age:
+            # If the fragment has not yet passed reclaim age then it is
+            # likely that a tombstone will be reverted to this node, or
+            # neighbor frags will get reverted from handoffs to *other* nodes
+            # and we'll discover we *do* have enough to reconstruct. Don't
+            # quarantine it yet: better that it is cleaned up 'normally'.
+            return False
+
+        bucket = buckets[local_timestamp]
+        return (bucket.num_responses <= self.quarantine_threshold and
+                bucket.num_responses < policy.ec_ndata and
+                df._frag_index in bucket.useful_responses)
+
+    def _make_fragment_requests(self, job, node, df, buckets, error_responses):
         """
         Issue requests for fragments to the list of ``nodes`` and sort the
         responses into per-timestamp ``buckets`` or per-status
@@ -492,16 +526,15 @@ class ObjectReconstructor(Daemon):
 
         :param job: job from ssync_sender.
         :param node: node to which we're rebuilding.
-        :param datafile_metadata:  the datafile metadata to attach to
-                                   the rebuilt fragment archive
+        :param df: an instance of :class:`~swift.obj.diskfile.BaseDiskFile`.
         :param buckets: dict of per-timestamp buckets for ok responses.
         :param error_responses: dict of per-status lists of error responses.
-        :param nodes: A list of nodes.
         :return: A per-timestamp with sufficient responses, or None if
             there is no such bucket.
         """
         policy = job['policy']
         partition = job['partition']
+        datafile_metadata = df.get_datafile_metadata()
 
         # the fragment index we need to reconstruct is the position index
         # of the node we're rebuilding to within the primary part list
@@ -521,24 +554,80 @@ class ObjectReconstructor(Daemon):
         headers['X-Backend-Fragment-Preferences'] = json.dumps(frag_prefs)
         path = datafile_metadata['name']
 
-        pile = GreenAsyncPile(len(nodes))
-        for _node in nodes:
-            full_get_path = _full_path(_node, partition, path, policy)
-            pile.spawn(self._get_response, _node, partition,
-                       path, headers, full_get_path)
+        ring = policy.object_ring
+        primary_nodes = ring.get_part_nodes(partition)
+        # primary_node_count is the maximum number of nodes to consume in a
+        # normal rebuild attempt when there is no quarantine candidate,
+        # including the node to which we are rebuilding
+        primary_node_count = len(primary_nodes)
+        # don't try and fetch a fragment from the node we're rebuilding to
+        filtered_primary_nodes = [n for n in primary_nodes
+                                  if n['id'] != node['id']]
+        # concurrency is the number of requests fired off in initial batch
+        concurrency = len(filtered_primary_nodes)
+        # max_node_count is the maximum number of nodes to consume when
+        # verifying a quarantine candidate and is at least primary_node_count
+        max_node_count = max(primary_node_count,
+                             self.request_node_count(primary_node_count))
 
+        pile = GreenAsyncPile(concurrency)
+        for primary_node in filtered_primary_nodes:
+            pile.spawn(self._get_response, primary_node, policy, partition,
+                       path, headers)
+
+        useful_bucket = None
         for resp in pile:
             bucket = self._handle_fragment_response(
                 node, policy, partition, fi_to_rebuild, path, buckets,
                 error_responses, resp)
             if bucket and len(bucket.useful_responses) >= policy.ec_ndata:
-                frag_indexes = list(bucket.useful_responses.keys())
-                self.logger.debug('Reconstruct frag #%s with frag indexes %s'
-                                  % (fi_to_rebuild, frag_indexes))
-                return bucket
-        return None
+                useful_bucket = bucket
+                break
 
-    def reconstruct_fa(self, job, node, datafile_metadata):
+        # Once all rebuild nodes have responded, if we have a quarantine
+        # candidate, go beyond primary_node_count and on to handoffs. The
+        # first non-404 response will prevent quarantine, but the expected
+        # common case is all 404 responses so we use some concurrency to get an
+        # outcome faster at the risk of some unnecessary requests in the
+        # uncommon case.
+        if (not useful_bucket and
+                self._is_quarantine_candidate(
+                    policy, buckets, error_responses, df)):
+            node_count = primary_node_count
+            handoff_iter = itertools.islice(ring.get_more_nodes(partition),
+                                            max_node_count - node_count)
+            for handoff_node in itertools.islice(handoff_iter, concurrency):
+                node_count += 1
+                pile.spawn(self._get_response, handoff_node, policy, partition,
+                           path, headers)
+            for resp in pile:
+                bucket = self._handle_fragment_response(
+                    node, policy, partition, fi_to_rebuild, path, buckets,
+                    error_responses, resp)
+                if bucket and len(bucket.useful_responses) >= policy.ec_ndata:
+                    useful_bucket = bucket
+                    self.logger.debug(
+                        'Reconstructing frag from handoffs, node_count=%d'
+                        % node_count)
+                    break
+                elif self._is_quarantine_candidate(
+                        policy, buckets, error_responses, df):
+                    try:
+                        handoff_node = next(handoff_iter)
+                        node_count += 1
+                        pile.spawn(self._get_response, handoff_node, policy,
+                                   partition, path, headers)
+                    except StopIteration:
+                        pass
+                # else: this frag is no longer a quarantine candidate, so we
+                # could break right here and ignore any remaining responses,
+                # but given that we may have actually found another frag we'll
+                # optimistically wait for any remaining responses in case a
+                # useful bucket is assembled.
+
+        return useful_bucket
+
+    def reconstruct_fa(self, job, node, df):
         """
         Reconstructs a fragment archive - this method is called from ssync
         after a remote node responds that is missing this object - the local
@@ -547,8 +636,7 @@ class ObjectReconstructor(Daemon):
 
         :param job: job from ssync_sender.
         :param node: node to which we're rebuilding.
-        :param datafile_metadata:  the datafile metadata to attach to
-                                   the rebuilt fragment archive
+        :param df: an instance of :class:`~swift.obj.diskfile.BaseDiskFile`.
         :returns: a DiskFile like class for use by ssync.
         :raises DiskFileQuarantined: if the fragment archive cannot be
             reconstructed and has as a result been quarantined.
@@ -559,6 +647,7 @@ class ObjectReconstructor(Daemon):
         # the fragment index we need to reconstruct is the position index
         # of the node we're rebuilding to within the primary part list
         fi_to_rebuild = node['backend_index']
+        datafile_metadata = df.get_datafile_metadata()
         local_timestamp = Timestamp(datafile_metadata['X-Timestamp'])
         path = datafile_metadata['name']
 
@@ -566,12 +655,13 @@ class ObjectReconstructor(Daemon):
         error_responses = defaultdict(list)  # map status code -> response list
 
         # don't try and fetch a fragment from the node we're rebuilding to
-        part_nodes = [n for n in policy.object_ring.get_part_nodes(partition)
-                      if n['id'] != node['id']]
         useful_bucket = self._make_fragment_requests(
-            job, node, datafile_metadata, buckets, error_responses, part_nodes)
+            job, node, df, buckets, error_responses)
 
         if useful_bucket:
+            frag_indexes = list(useful_bucket.useful_responses.keys())
+            self.logger.debug('Reconstruct frag #%s with frag indexes %s'
+                              % (fi_to_rebuild, frag_indexes))
             responses = list(useful_bucket.useful_responses.values())
             rebuilt_fragment_iter = self.make_rebuilt_fragment_iter(
                 responses[:policy.ec_ndata], path, policy, fi_to_rebuild)
@@ -601,6 +691,10 @@ class ObjectReconstructor(Daemon):
                     errors, 'durable' if durable else 'non-durable',
                     full_path, fi_to_rebuild))
 
+        if self._is_quarantine_candidate(policy, buckets, error_responses, df):
+            raise df._quarantine(
+                df._data_file, "Solitary fragment #%s" % df._frag_index)
+
         raise DiskFileError('Unable to reconstruct EC archive')
 
     def _reconstruct(self, policy, fragment_payload, frag_index):
diff --git a/swift/obj/ssync_sender.py b/swift/obj/ssync_sender.py
index 2a42fbf01e..27d143210c 100644
--- a/swift/obj/ssync_sender.py
+++ b/swift/obj/ssync_sender.py
@@ -374,7 +374,7 @@ class Sender(object):
                     # from the data file only.
                     df_alt = self.job.get(
                         'sync_diskfile_builder', lambda *args: df)(
-                            self.job, self.node, df.get_datafile_metadata())
+                            self.job, self.node, df)
                     self.send_put(connection, url_path, df_alt,
                                   durable=is_durable)
                 if want.get('meta') and df.data_timestamp != df.timestamp:
diff --git a/swift/proxy/server.py b/swift/proxy/server.py
index 21802c47fb..6bd7fbe918 100644
--- a/swift/proxy/server.py
+++ b/swift/proxy/server.py
@@ -35,7 +35,8 @@ from swift.common.ring import Ring
 from swift.common.utils import Watchdog, get_logger, \
     get_remote_client, split_path, config_true_value, generate_trans_id, \
     affinity_key_function, affinity_locality_predicate, list_from_csv, \
-    register_swift_info, parse_prefixed_conf, config_auto_int_value
+    register_swift_info, parse_prefixed_conf, config_auto_int_value, \
+    config_request_node_count_value
 from swift.common.constraints import check_utf8, valid_api_version
 from swift.proxy.controllers import AccountController, ContainerController, \
     ObjectControllerRouter, InfoController
@@ -279,16 +280,8 @@ class Application(object):
             conf.get('strict_cors_mode', 't'))
         self.node_timings = {}
         self.timing_expiry = int(conf.get('timing_expiry', 300))
-        value = conf.get('request_node_count', '2 * replicas').lower().split()
-        if len(value) == 1:
-            rnc_value = int(value[0])
-            self.request_node_count = lambda replicas: rnc_value
-        elif len(value) == 3 and value[1] == '*' and value[2] == 'replicas':
-            rnc_value = int(value[0])
-            self.request_node_count = lambda replicas: rnc_value * replicas
-        else:
-            raise ValueError(
-                'Invalid request_node_count value: %r' % ''.join(value))
+        value = conf.get('request_node_count', '2 * replicas')
+        self.request_node_count = config_request_node_count_value(value)
         # swift_owner_headers are stripped by the account and container
         # controllers; we should extend header stripping to object controller
         # when a privileged object header is implemented.
diff --git a/test/probe/common.py b/test/probe/common.py
index 5c437e20d4..fac9daea08 100644
--- a/test/probe/common.py
+++ b/test/probe/common.py
@@ -33,7 +33,7 @@ from six.moves.http_client import HTTPConnection
 from six.moves.urllib.parse import urlparse
 
 from swiftclient import get_auth, head_account, client
-from swift.common import internal_client, direct_client
+from swift.common import internal_client, direct_client, utils
 from swift.common.direct_client import DirectClientException
 from swift.common.ring import Ring
 from swift.common.utils import readconf, renamer, \
@@ -41,6 +41,7 @@ from swift.common.utils import readconf, renamer, \
 from swift.common.manager import Manager
 from swift.common.storage_policy import POLICIES, EC_POLICY, REPL_POLICY
 from swift.obj.diskfile import get_data_dir
+from test.debug_logger import debug_logger
 
 from test.probe import CHECK_SERVER_TIMEOUT, VALIDATE_RSYNC, PROXY_BASE_URL
 
@@ -186,6 +187,8 @@ def store_config_paths(name, configs):
     server_names = [name, '%s-replicator' % name]
     if name == 'container':
         server_names.append('container-sharder')
+    elif name == 'object':
+        server_names.append('object-reconstructor')
     for server_name in server_names:
         for server in Manager([server_name]):
             for i, conf in enumerate(server.conf_files(), 1):
@@ -563,6 +566,15 @@ class ProbeTest(unittest.TestCase):
                             for ent in os.listdir(ap_dir_fullpath)])
         return async_pendings
 
+    def run_custom_daemon(self, klass, conf_section, conf_index,
+                          custom_conf, **kwargs):
+        conf_file = self.configs[conf_section][conf_index]
+        conf = utils.readconf(conf_file, conf_section)
+        conf.update(custom_conf)
+        daemon = klass(conf, debug_logger('probe'))
+        daemon.run_once(**kwargs)
+        return daemon
+
 
 class ReplProbeTest(ProbeTest):
 
@@ -679,6 +691,7 @@ class ECProbeTest(ProbeTest):
             self.direct_get(onode, opart, require_durable=require_durable)
         except direct_client.DirectClientException as err:
             self.assertEqual(err.http_status, status)
+            return err
         else:
             self.fail('Node data on %r was not fully destroyed!' % (onode,))
 
diff --git a/test/probe/test_reconstructor_rebuild.py b/test/probe/test_reconstructor_rebuild.py
index 9f8e491a5b..e87cd95785 100644
--- a/test/probe/test_reconstructor_rebuild.py
+++ b/test/probe/test_reconstructor_rebuild.py
@@ -13,7 +13,7 @@
 # implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import itertools
 from contextlib import contextmanager
 import unittest
 import uuid
@@ -22,7 +22,9 @@ import time
 import six
 
 from swift.common.direct_client import DirectClientException
+from swift.common.manager import Manager
 from swift.common.utils import md5
+from swift.obj.reconstructor import ObjectReconstructor
 from test.probe.common import ECProbeTest
 
 from swift.common import direct_client
@@ -369,6 +371,160 @@ class TestReconstructorRebuild(ECProbeTest):
                     'X-Backend-Storage-Policy-Index': int(self.policy)})
             self.assertNotIn('X-Delete-At', headers)
 
+    def test_rebuild_quarantines_lonely_frag(self):
+        # fail one device while the object is deleted so we are left with one
+        # fragment and some tombstones
+        failed_node = self.onodes[0]
+        device_path = self.device_dir(failed_node)
+        self.kill_drive(device_path)
+        self.assert_direct_get_fails(failed_node, self.opart, 507)  # sanity
+
+        # delete object
+        client.delete_object(self.url, self.token, self.container_name,
+                             self.object_name)
+
+        # check we have tombstones
+        for node in self.onodes[1:]:
+            err = self.assert_direct_get_fails(node, self.opart, 404)
+            self.assertIn('X-Backend-Timestamp', err.http_headers)
+
+        # run the reconstructor with zero reclaim age to clean up tombstones
+        for conf_index in self.configs['object-reconstructor'].keys():
+            self.run_custom_daemon(
+                ObjectReconstructor, 'object-reconstructor', conf_index,
+                {'reclaim_age': '0'})
+
+        # check we no longer have tombstones
+        for node in self.onodes[1:]:
+            err = self.assert_direct_get_fails(node, self.opart, 404)
+            self.assertNotIn('X-Timestamp', err.http_headers)
+
+        # revive the failed device and check it has a fragment
+        self.revive_drive(device_path)
+        self.assert_direct_get_succeeds(failed_node, self.opart)
+
+        # restart proxy to clear error-limiting so that the revived drive
+        # participates again
+        Manager(['proxy-server']).restart()
+
+        # client GET will fail with 503 ...
+        with self.assertRaises(ClientException) as cm:
+            client.get_object(self.url, self.token, self.container_name,
+                              self.object_name)
+        self.assertEqual(503, cm.exception.http_status)
+        # ... but client GET succeeds
+        headers = client.head_object(self.url, self.token, self.container_name,
+                                     self.object_name)
+        for key in self.headers_post:
+            self.assertIn(key, headers)
+            self.assertEqual(self.headers_post[key], headers[key])
+
+        # run the reconstructor without quarantine_threshold set
+        error_lines = []
+        warning_lines = []
+        for conf_index in self.configs['object-reconstructor'].keys():
+            reconstructor = self.run_custom_daemon(
+                ObjectReconstructor, 'object-reconstructor', conf_index,
+                {'reclaim_age': '0'})
+            logger = reconstructor.logger.logger
+            error_lines.append(logger.get_lines_for_level('error'))
+            warning_lines.append(logger.get_lines_for_level('warning'))
+
+        # check logs for errors
+        found_lines = False
+        for lines in error_lines:
+            if not lines:
+                continue
+            self.assertFalse(found_lines, error_lines)
+            found_lines = True
+            for line in itertools.islice(lines, 0, 6, 2):
+                self.assertIn(
+                    'Unable to get enough responses (1/4 from 1 ok '
+                    'responses)', line, lines)
+            for line in itertools.islice(lines, 1, 7, 2):
+                self.assertIn(
+                    'Unable to get enough responses (4 x 404 error '
+                    'responses)', line, lines)
+        self.assertTrue(found_lines, 'error lines not found')
+
+        for lines in warning_lines:
+            self.assertEqual([], lines)
+
+        # check we have still have a single fragment and no tombstones
+        self.assert_direct_get_succeeds(failed_node, self.opart)
+        for node in self.onodes[1:]:
+            err = self.assert_direct_get_fails(node, self.opart, 404)
+            self.assertNotIn('X-Timestamp', err.http_headers)
+
+        # run the reconstructor to quarantine the lonely frag
+        error_lines = []
+        warning_lines = []
+        for conf_index in self.configs['object-reconstructor'].keys():
+            reconstructor = self.run_custom_daemon(
+                ObjectReconstructor, 'object-reconstructor', conf_index,
+                {'reclaim_age': '0', 'quarantine_threshold': '1'})
+            logger = reconstructor.logger.logger
+            error_lines.append(logger.get_lines_for_level('error'))
+            warning_lines.append(logger.get_lines_for_level('warning'))
+
+        # check logs for errors
+        found_lines = False
+        for index, lines in enumerate(error_lines):
+            if not lines:
+                continue
+            self.assertFalse(found_lines, error_lines)
+            found_lines = True
+            for line in itertools.islice(lines, 0, 6, 2):
+                self.assertIn(
+                    'Unable to get enough responses (1/4 from 1 ok '
+                    'responses)', line, lines)
+            for line in itertools.islice(lines, 1, 7, 2):
+                self.assertIn(
+                    'Unable to get enough responses (6 x 404 error '
+                    'responses)', line, lines)
+        self.assertTrue(found_lines, 'error lines not found')
+
+        # check logs for quarantine warning
+        found_lines = False
+        for lines in warning_lines:
+            if not lines:
+                continue
+            self.assertFalse(found_lines, warning_lines)
+            found_lines = True
+            self.assertEqual(1, len(lines), lines)
+            self.assertIn('Quarantined object', lines[0])
+        self.assertTrue(found_lines, 'warning lines not found')
+
+        # check we have nothing
+        for node in self.onodes:
+            err = self.assert_direct_get_fails(node, self.opart, 404)
+            self.assertNotIn('X-Backend-Timestamp', err.http_headers)
+        # client HEAD and GET now both 404
+        with self.assertRaises(ClientException) as cm:
+            client.get_object(self.url, self.token, self.container_name,
+                              self.object_name)
+        self.assertEqual(404, cm.exception.http_status)
+        with self.assertRaises(ClientException) as cm:
+            client.head_object(self.url, self.token, self.container_name,
+                               self.object_name)
+        self.assertEqual(404, cm.exception.http_status)
+
+        # run the reconstructor once more - should see no errors in logs!
+        error_lines = []
+        warning_lines = []
+        for conf_index in self.configs['object-reconstructor'].keys():
+            reconstructor = self.run_custom_daemon(
+                ObjectReconstructor, 'object-reconstructor', conf_index,
+                {'reclaim_age': '0', 'quarantine_threshold': '1'})
+            logger = reconstructor.logger.logger
+            error_lines.append(logger.get_lines_for_level('error'))
+            warning_lines.append(logger.get_lines_for_level('warning'))
+
+        for lines in error_lines:
+            self.assertEqual([], lines)
+        for lines in warning_lines:
+            self.assertEqual([], lines)
+
 
 if six.PY2:
     class TestReconstructorRebuildUTF8(TestReconstructorRebuild):
diff --git a/test/probe/test_sharder.py b/test/probe/test_sharder.py
index 96511f6fce..2e8647c21f 100644
--- a/test/probe/test_sharder.py
+++ b/test/probe/test_sharder.py
@@ -40,7 +40,6 @@ from test.probe import PROXY_BASE_URL
 from test.probe.brain import BrainSplitter
 from test.probe.common import ReplProbeTest, get_server_number, \
     wait_for_server_to_hangup
-from test.debug_logger import debug_logger
 import mock
 
 
@@ -415,12 +414,8 @@ class BaseTestContainerSharding(ReplProbeTest):
                                additional_args='--partitions=%s' % part)
 
     def run_custom_sharder(self, conf_index, custom_conf, **kwargs):
-        conf_file = self.configs['container-sharder'][conf_index]
-        conf = utils.readconf(conf_file, 'container-sharder')
-        conf.update(custom_conf)
-        sharder = ContainerSharder(conf, logger=debug_logger('probe'))
-        sharder.run_once(**kwargs)
-        return sharder
+        return self.run_custom_daemon(ContainerSharder, 'container-sharder',
+                                      conf_index, custom_conf, **kwargs)
 
 
 class TestContainerShardingNonUTF8(BaseTestContainerSharding):
diff --git a/test/unit/common/test_utils.py b/test/unit/common/test_utils.py
index 5582edf8d4..a6d1741752 100644
--- a/test/unit/common/test_utils.py
+++ b/test/unit/common/test_utils.py
@@ -18,6 +18,7 @@ from __future__ import print_function
 
 import hashlib
 
+from test import annotate_failure
 from test.debug_logger import debug_logger
 from test.unit import temptree, make_timestamp_iter, with_tempdir, \
     mock_timestamp_now, FakeIterable
@@ -3156,6 +3157,27 @@ cluster_dfw1 = http://dfw1.host/v1/
                           'less than 100, not "{}"'.format(val),
                           cm.exception.args[0])
 
+    def test_config_request_node_count_value(self):
+        def do_test(value, replicas, expected):
+            self.assertEqual(
+                expected,
+                utils.config_request_node_count_value(value)(replicas))
+
+        do_test('0', 10, 0)
+        do_test('1 * replicas', 3, 3)
+        do_test('1 * replicas', 11, 11)
+        do_test('2 * replicas', 3, 6)
+        do_test('2 * replicas', 11, 22)
+        do_test('11', 11, 11)
+        do_test('10', 11, 10)
+        do_test('12', 11, 12)
+
+        for bad in ('1.1', 1.1, 'auto', 'bad',
+                    '2.5 * replicas', 'two * replicas'):
+            with annotate_failure(bad):
+                with self.assertRaises(ValueError):
+                    utils.config_request_node_count_value(bad)
+
     def test_config_auto_int_value(self):
         expectations = {
             # (value, default) : expected,
diff --git a/test/unit/obj/test_reconstructor.py b/test/unit/obj/test_reconstructor.py
index dc98fae975..86ddddb712 100644
--- a/test/unit/obj/test_reconstructor.py
+++ b/test/unit/obj/test_reconstructor.py
@@ -34,7 +34,7 @@ from gzip import GzipFile
 from shutil import rmtree
 from six.moves.urllib.parse import unquote
 from swift.common import utils
-from swift.common.exceptions import DiskFileError
+from swift.common.exceptions import DiskFileError, DiskFileQuarantined
 from swift.common.header_key_dict import HeaderKeyDict
 from swift.common.utils import dump_recon_cache, md5
 from swift.obj import diskfile, reconstructor as object_reconstructor
@@ -42,6 +42,7 @@ from swift.common import ring
 from swift.common.storage_policy import (StoragePolicy, ECStoragePolicy,
                                          POLICIES, EC_POLICY)
 from swift.obj.reconstructor import SYNC, REVERT
+from test import annotate_failure
 
 from test.debug_logger import debug_logger
 from test.unit import (patch_policies, mocked_http_conn, FabricatedRing,
@@ -785,10 +786,8 @@ class TestGlobalSetupObjectReconstructor(unittest.TestCase):
 
         def do_test(stat_code):
             with mocked_http_conn(stat_code):
-                resp = self.reconstructor._get_response(node, part,
-                                                        path='nada',
-                                                        headers={},
-                                                        full_path='nada/nada')
+                resp = self.reconstructor._get_response(
+                    node, self.policy, part, path='nada', headers={})
             return resp
 
         for status in (200, 400, 404, 503):
@@ -4528,17 +4527,27 @@ class TestObjectReconstructor(BaseTestObjectReconstructor):
 
 
 class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
-    obj_path = b'/a/c/o'  # subclass overrides this
+    obj_name = b'o'  # subclass overrides this
 
     def setUp(self):
         super(TestReconstructFragmentArchive, self).setUp()
+        self.obj_path = b'/a/c/' + self.obj_name
         self.obj_timestamp = self.ts()
-        self.obj_metadata = {
-            'name': self.obj_path,
-            'Content-Length': '0',
-            'ETag': 'etag',
-            'X-Timestamp': self.obj_timestamp.normal
-        }
+
+    def _create_fragment(self, frag_index, body=b'test data'):
+        utils.mkdirs(os.path.join(self.devices, 'sda1'))
+        df_mgr = self.reconstructor._df_router[self.policy]
+        if six.PY2:
+            obj_name = self.obj_name
+        else:
+            obj_name = self.obj_name.decode('utf8')
+        self.df = df_mgr.get_diskfile('sda1', 9, 'a', 'c', obj_name,
+                                      policy=self.policy)
+        write_diskfile(self.df, self.obj_timestamp, data=body,
+                       frag_index=frag_index)
+        self.df.open()
+        self.logger.clear()
+        return self.df
 
     def test_reconstruct_fa_no_errors(self):
         job = {
@@ -4565,9 +4574,9 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         called_headers = []
         orig_func = object_reconstructor.ObjectReconstructor._get_response
 
-        def _get_response_hook(self, node, part, path, headers, policy):
+        def _get_response_hook(self, node, policy, part, path, headers):
             called_headers.append(headers)
-            return orig_func(self, node, part, path, headers, policy)
+            return orig_func(self, node, policy, part, path, headers)
 
         codes, body_iter, headers = zip(*responses)
         get_response_path = \
@@ -4576,7 +4585,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
             with mocked_http_conn(
                     *codes, body_iter=body_iter, headers=headers):
                 df = self.reconstructor.reconstruct_fa(
-                    job, node, self.obj_metadata)
+                    job, node, self._create_fragment(2, body=b''))
                 self.assertEqual(0, df.content_length)
                 fixed_body = b''.join(df.reader())
         self.assertEqual(len(fixed_body), len(broken_body))
@@ -4635,7 +4644,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
             with mocked_http_conn(*codes, body_iter=body_iter,
                                   headers=headers_iter):
                 df = self.reconstructor.reconstruct_fa(
-                    job, node, dict(self.obj_metadata))
+                    job, node, self._create_fragment(2))
                 fixed_body = b''.join(df.reader())
                 self.assertEqual(len(fixed_body), len(broken_body))
                 self.assertEqual(
@@ -4676,7 +4685,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         with mocked_http_conn(*codes, body_iter=body_iter,
                               headers=headers_iter):
             df = self.reconstructor.reconstruct_fa(
-                job, node, dict(self.obj_metadata))
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -4722,7 +4731,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         with mocked_http_conn(*codes, body_iter=body_iter,
                               headers=headers_iter):
             df = self.reconstructor.reconstruct_fa(
-                job, node, dict(self.obj_metadata))
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             # ... this bad response should be ignored like any other failure
             self.assertEqual(len(fixed_body), len(broken_body))
@@ -4761,7 +4770,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
             with mocked_http_conn(*codes, body_iter=body_iter,
                                   headers=headers_iter):
                 df = self.reconstructor.reconstruct_fa(
-                    job, node, dict(self.obj_metadata))
+                    job, node, self._create_fragment(2))
                 fixed_body = b''.join(df.reader())
                 self.assertEqual(len(fixed_body), len(broken_body))
                 self.assertEqual(
@@ -4783,7 +4792,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
                  range(policy.object_ring.replicas - 1)]
         with mocked_http_conn(*codes):
             self.assertRaises(DiskFileError, self.reconstructor.reconstruct_fa,
-                              job, node, self.obj_metadata)
+                              job, node, self._create_fragment(2))
         error_lines = self.logger.get_lines_for_level('error')
         # # of replicas failed and one more error log to report not enough
         # responses to reconstruct.
@@ -4799,6 +4808,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         self.assertFalse(self.logger.get_lines_for_level('warning'))
 
     def test_reconstruct_fa_all_404s_fails(self):
+        self._create_fragment(2)
         job = {
             'partition': 0,
             'policy': self.policy,
@@ -4811,7 +4821,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes = [404 for i in range(policy.object_ring.replicas - 1)]
         with mocked_http_conn(*codes):
             self.assertRaises(DiskFileError, self.reconstructor.reconstruct_fa,
-                              job, node, self.obj_metadata)
+                              job, node, self.df)
         error_lines = self.logger.get_lines_for_level('error')
         # only 1 log to report not enough responses
         self.assertEqual(1, len(error_lines))
@@ -4823,7 +4833,51 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         # no warning
         self.assertFalse(self.logger.get_lines_for_level('warning'))
 
+    def test_reconstruct_fa_all_404s_fails_custom_request_node_count(self):
+        # verify that when quarantine_threshold is not set the number of
+        # requests is capped at replicas - 1 regardless of request_node_count
+        self._create_fragment(2)
+        job = {
+            'partition': 0,
+            'policy': self.policy,
+        }
+        part_nodes = self.policy.object_ring.get_part_nodes(0)
+        node = part_nodes[1]
+        node['backend_index'] = self.policy.get_backend_index(node['index'])
+        ring = self.policy.object_ring
+        # sanity check: number of handoffs available == replicas
+        self.assertEqual(ring.max_more_nodes, ring.replicas)
+        for request_node_count in (0,
+                                   self.policy.ec_ndata - 1,
+                                   ring.replicas + 1,
+                                   2 * ring.replicas - 1,
+                                   2 * ring.replicas,
+                                   3 * ring.replicas,
+                                   99 * ring.replicas):
+            with annotate_failure(request_node_count):
+                self.logger.clear()
+                self.reconstructor.request_node_count = \
+                    lambda replicas: request_node_count
+                # request count capped at num primaries - 1
+                exp_requests = ring.replicas - 1
+                codes = [404 for i in range(exp_requests)]
+                with mocked_http_conn(*codes):
+                    self.assertRaises(DiskFileError,
+                                      self.reconstructor.reconstruct_fa,
+                                      job, node, self.df)
+                error_lines = self.logger.get_lines_for_level('error')
+                # only 1 log to report not enough responses
+                self.assertEqual(1, len(error_lines))
+                self.assertIn(
+                    'Unable to get enough responses (%s x 404 error responses)'
+                    % exp_requests,
+                    error_lines[0],
+                    "Unexpected error line found: %s" % error_lines[0])
+                # no warning
+                self.assertFalse(self.logger.get_lines_for_level('warning'))
+
     def test_reconstruct_fa_mixture_of_errors_fails(self):
+        self._create_fragment(2)
         job = {
             'partition': 0,
             'policy': self.policy,
@@ -4839,7 +4893,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
                                    range(policy.object_ring.replicas - 4)]
         with mocked_http_conn(*codes):
             self.assertRaises(DiskFileError, self.reconstructor.reconstruct_fa,
-                              job, node, self.obj_metadata)
+                              job, node, self.df)
         exp_timeouts = len([c for c in codes if isinstance(c, Timeout)])
         exp_404s = len([c for c in codes if c == 404])
         exp_507s = len([c for c in codes if c == 507])
@@ -4901,7 +4955,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             df = self.reconstructor.reconstruct_fa(
-                job, node, self.obj_metadata)
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -4941,7 +4995,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             df = self.reconstructor.reconstruct_fa(
-                job, node, dict(self.obj_metadata))
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -4958,7 +5012,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             df = self.reconstructor.reconstruct_fa(
-                job, node, dict(self.obj_metadata))
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -4995,7 +5049,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             df = self.reconstructor.reconstruct_fa(
-                job, node, dict(self.obj_metadata))
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -5016,7 +5070,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             df = self.reconstructor.reconstruct_fa(
-                job, node, dict(self.obj_metadata))
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -5080,7 +5134,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             self.assertRaises(DiskFileError, self.reconstructor.reconstruct_fa,
-                              job, node, self.obj_metadata)
+                              job, node, self._create_fragment(2))
 
         error_lines = self.logger.get_lines_for_level('error')
         # 1 error log per etag to report not enough responses
@@ -5111,6 +5165,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         self.assertFalse(self.logger.get_lines_for_level('warning'))
 
     def test_reconstruct_fa_with_mixed_etags_same_timestamp_fail(self):
+        self._create_fragment(2)
         job = {
             'partition': 0,
             'policy': self.policy,
@@ -5157,7 +5212,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             self.assertRaises(DiskFileError, self.reconstructor.reconstruct_fa,
-                              job, node, self.obj_metadata)
+                              job, node, self.df)
 
         error_lines = self.logger.get_lines_for_level('error')
         self.assertGreater(len(error_lines), 1)
@@ -5219,7 +5274,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             df = self.reconstructor.reconstruct_fa(
-                job, node, self.obj_metadata)
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -5234,7 +5289,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         # redundant frag found once in first ec_ndata responses
         self.assertIn(
             'Found existing frag #%s at' % broken_index,
-            debug_log_lines[0])
+            debug_log_lines[0], debug_log_lines)
 
         # N.B. in the future, we could avoid those check because
         # definitely sending the copy rather than reconstruct will
@@ -5251,6 +5306,537 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
             debug_log_lines[1][len(log_prefix):])
         self.assertNotIn(broken_index, got_frag_index_list)
 
+    def test_quarantine_threshold_conf(self):
+        reconstructor = object_reconstructor.ObjectReconstructor({})
+        self.assertEqual(0, reconstructor.quarantine_threshold)
+
+        reconstructor = object_reconstructor.ObjectReconstructor(
+            {'quarantine_threshold': '0'})
+        self.assertEqual(0, reconstructor.quarantine_threshold)
+
+        reconstructor = object_reconstructor.ObjectReconstructor(
+            {'quarantine_threshold': '1'})
+        self.assertEqual(1, reconstructor.quarantine_threshold)
+
+        reconstructor = object_reconstructor.ObjectReconstructor(
+            {'quarantine_threshold': 2.0})
+        self.assertEqual(2, reconstructor.quarantine_threshold)
+
+        for bad in ('1.1', 1.1, '-1', -1, 'auto', 'bad'):
+            with annotate_failure(bad):
+                with self.assertRaises(ValueError):
+                    object_reconstructor.ObjectReconstructor(
+                        {'quarantine_threshold': bad})
+
+    def test_request_node_count_conf(self):
+        # default is 1 * replicas
+        reconstructor = object_reconstructor.ObjectReconstructor({})
+        self.assertEqual(6, reconstructor.request_node_count(3))
+        self.assertEqual(22, reconstructor.request_node_count(11))
+
+        def do_test(value, replicas, expected):
+            reconstructor = object_reconstructor.ObjectReconstructor(
+                {'request_node_count': value})
+            self.assertEqual(expected,
+                             reconstructor.request_node_count(replicas))
+        do_test('0', 10, 0)
+        do_test('1 * replicas', 3, 3)
+        do_test('1 * replicas', 11, 11)
+        do_test('2 * replicas', 3, 6)
+        do_test('2 * replicas', 11, 22)
+        do_test('11', 11, 11)
+        do_test('10', 11, 10)
+        do_test('12', 11, 12)
+
+        for bad in ('1.1', 1.1, 'auto', 'bad',
+                    '2.5 * replicas', 'two * replicas'):
+            with annotate_failure(bad):
+                with self.assertRaises(ValueError):
+                    object_reconstructor.ObjectReconstructor(
+                        {'request_node_count': bad})
+
+    def _do_test_reconstruct_insufficient_frags(
+            self, extra_conf, num_frags, other_responses,
+            local_frag_index=2, frag_index_to_rebuild=1,
+            resp_timestamps=None, resp_etags=None):
+        # num_frags is number of ok responses, other_responses is bad responses
+        # By default frag_index_to_rebuild is less than local_frag_index and
+        # all frag responses have indexes >= local_frag_index
+        self.assertGreater(num_frags, 0)
+        self.logger.clear()
+        self._configure_reconstructor(**extra_conf)
+        self._create_fragment(local_frag_index)
+        job = {
+            'partition': 0,
+            'policy': self.policy,
+        }
+        part_nodes = self.policy.object_ring.get_part_nodes(0)
+        node = part_nodes[frag_index_to_rebuild]
+        node['backend_index'] = self.policy.get_backend_index(node['index'])
+
+        test_data = (b'rebuild' * self.policy.ec_segment_size)[:-777]
+        etag = md5(test_data, usedforsecurity=False).hexdigest()
+        ec_archive_bodies = encode_frag_archive_bodies(self.policy, test_data)
+        frags = ec_archive_bodies[
+            local_frag_index:local_frag_index + num_frags]
+
+        if resp_etags:
+            self.assertEqual(len(frags), len(resp_etags))
+            etags = []
+            for other_etag in resp_etags:
+                # use default etag where other_etag is None
+                etags.append(other_etag if other_etag else etag)
+        else:
+            etags = [etag] * len(frags)
+
+        def make_header(body):
+            headers = get_header_frag_index(self, body)
+            headers.update({'X-Object-Sysmeta-Ec-Etag': etags.pop(0)})
+            return headers
+
+        responses = [(200, frag, make_header(frag)) for frag in frags]
+        codes, body_iter, headers = zip(*(responses + other_responses))
+        resp_timestamps = (resp_timestamps if resp_timestamps
+                           else [self.obj_timestamp] * len(codes))
+        resp_timestamps = [ts.internal for ts in resp_timestamps]
+        with mocked_http_conn(*codes, body_iter=body_iter,
+                              headers=headers,
+                              timestamps=resp_timestamps):
+            with self.assertRaises(DiskFileError) as cm:
+                self.reconstructor.reconstruct_fa(
+                    job, node, self._create_fragment(2))
+        return cm.exception
+
+    def _verify_error_lines(self, num_frags, other_responses,
+                            exp_useful_responses):
+        error_lines = self.logger.get_lines_for_level('error')
+        self.assertEqual(2, len(error_lines), error_lines)
+        self.assertIn(
+            'Unable to get enough responses (%d/%d from %d ok responses)'
+            % (exp_useful_responses, self.policy.ec_ndata, num_frags),
+            error_lines[0])
+        bad_codes = collections.Counter(
+            status for status, _, _ in other_responses)
+        errors = ', '.join('%s x %s' % (num, code)
+                           for code, num in sorted(bad_codes.items()))
+        self.assertIn('Unable to get enough responses (%s error responses)'
+                      % errors, error_lines[1])
+
+    def _assert_diskfile_quarantined(self):
+        warning_lines = self.logger.get_lines_for_level('warning')
+        self.assertEqual(1, len(warning_lines), warning_lines)
+        self.assertIn('Quarantined object', warning_lines[0])
+
+        # Check the diskfile has moved to quarantine dir
+        data_filename = os.path.basename(self.df._data_file)
+        df_hash = os.path.basename(self.df._datadir)
+        quarantine_dir = os.path.join(
+            self.df._device_path, 'quarantined',
+            diskfile.get_data_dir(self.policy), df_hash)
+        self.assertTrue(os.path.isdir(quarantine_dir))
+        quarantine_file = os.path.join(quarantine_dir, data_filename)
+        self.assertTrue(os.path.isfile(quarantine_file))
+        with open(quarantine_file, 'r') as fd:
+            self.assertEqual('test data', fd.read())
+        self.assertFalse(os.path.exists(self.df._data_file))
+
+    def _assert_diskfile_not_quarantined(self):
+        # Check the diskfile has not moved to quarantine dir
+        quarantine_dir = os.path.join(
+            self.df._device_path, 'quarantined')
+        self.assertFalse(os.path.isdir(quarantine_dir))
+        self.assertTrue(os.path.exists(self.df._data_file))
+        with open(self.df._data_file, 'r') as fd:
+            self.assertEqual('test data', fd.read())
+
+    def test_reconstruct_fa_quarantine_threshold_one_rnc_two_replicas(self):
+        # use default request_node_count == 2 * replicas
+        num_other_resps = 2 * self.policy.object_ring.replicas - 2
+        other_responses = [(404, None, None)] * num_other_resps
+        conf = {'quarantine_threshold': 1, 'reclaim_age': 0}
+        exc = self._do_test_reconstruct_insufficient_frags(
+            conf, 1, other_responses)
+        self.assertIsInstance(exc, DiskFileQuarantined)
+        self._assert_diskfile_quarantined()
+        self._verify_error_lines(1, other_responses, 1)
+
+    def test_reconstruct_fa_quarantine_threshold_one_rnc_three_replicas(self):
+        num_other_resps = 3 * self.policy.object_ring.replicas - 2
+        other_responses = [(404, None, None)] * num_other_resps
+        conf = {'quarantine_threshold': 1, 'reclaim_age': 0,
+                'request_node_count': '3 * replicas'}
+        # set ring get_more_nodes to yield enough handoffs
+        self.policy.object_ring.max_more_nodes = (
+            2 * self.policy.object_ring.replicas)
+        exc = self._do_test_reconstruct_insufficient_frags(
+            conf, 1, other_responses)
+        self.assertIsInstance(exc, DiskFileQuarantined)
+        self._assert_diskfile_quarantined()
+        self._verify_error_lines(1, other_responses, 1)
+
+    def test_reconstruct_fa_quarantine_threshold_one_rnc_four_replicas(self):
+        # verify handoff search exhausting handoff node iter
+        num_other_resps = 3 * self.policy.object_ring.replicas - 2
+        other_responses = [(404, None, None)] * num_other_resps
+        conf = {'quarantine_threshold': 1, 'reclaim_age': 0,
+                'request_node_count': '4 * replicas'}
+        # limit ring get_more_nodes to yield less than
+        # (request_node_count - 1 * replicas) nodes
+        self.policy.object_ring.max_more_nodes = (
+            2 * self.policy.object_ring.replicas)
+        exc = self._do_test_reconstruct_insufficient_frags(
+            conf, 1, other_responses)
+        self.assertIsInstance(exc, DiskFileQuarantined)
+        self._assert_diskfile_quarantined()
+        self._verify_error_lines(1, other_responses, 1)
+
+    def test_reconstruct_fa_quarantine_threshold_one_rnc_absolute_number(self):
+        def do_test(rnc_num):
+            if rnc_num < self.policy.object_ring.replicas:
+                num_other_resps = self.policy.object_ring.replicas - 2
+            else:
+                num_other_resps = rnc_num - 2
+            other_responses = [(404, None, None)] * num_other_resps
+            conf = {'quarantine_threshold': 1, 'reclaim_age': 0,
+                    'request_node_count': str(rnc_num)}
+            # set ring get_more_nodes to yield enough handoffs
+            self.policy.object_ring.max_more_nodes = (
+                2 * self.policy.object_ring.replicas)
+            exc = self._do_test_reconstruct_insufficient_frags(
+                conf, 1, other_responses)
+            self.assertIsInstance(exc, DiskFileQuarantined)
+            self._assert_diskfile_quarantined()
+            self._verify_error_lines(1, other_responses, 1)
+
+        for rnc_num in range(0, 3 * self.policy.object_ring.replicas):
+            do_test(rnc_num)
+
+    def test_reconstruct_fa_quarantine_threshold_two(self):
+        num_other_resps = 2 * self.policy.object_ring.replicas - 3
+        other_responses = [(404, None, None)] * num_other_resps
+        conf = {'quarantine_threshold': 2, 'reclaim_age': 0}
+        exc = self._do_test_reconstruct_insufficient_frags(
+            conf, 2, other_responses)
+        self.assertIsInstance(exc, DiskFileQuarantined)
+        self._assert_diskfile_quarantined()
+        self._verify_error_lines(2, other_responses, 2)
+
+    def test_reconstruct_fa_no_quarantine_more_than_threshold_frags(self):
+        # default config
+        num_other_resps = self.policy.object_ring.replicas - 2
+        other_responses = [(404, None, None)] * num_other_resps
+        exc = self._do_test_reconstruct_insufficient_frags(
+            {'reclaim_age': 0}, 1, other_responses)
+        self.assertIsInstance(exc, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+
+        # configured quarantine_threshold
+        for quarantine_threshold in range(self.policy.ec_ndata):
+            for num_frags in range(quarantine_threshold + 1,
+                                   self.policy.ec_ndata):
+                num_other_resps = (self.policy.object_ring.replicas -
+                                   num_frags - 1)
+                other_responses = [(404, None, None)] * num_other_resps
+                exc = self._do_test_reconstruct_insufficient_frags(
+                    {'quarantine_threshold': quarantine_threshold,
+                     'reclaim_age': 0},
+                    num_frags, other_responses)
+                self.assertIsInstance(exc, DiskFileError)
+                self._assert_diskfile_not_quarantined()
+                self._verify_error_lines(num_frags, other_responses, num_frags)
+                warning_lines = self.logger.get_lines_for_level('warning')
+                self.assertEqual([], warning_lines)
+
+        # responses include the frag_index_to_rebuild - verify that response is
+        # counted against the threshold
+        num_other_resps = self.policy.object_ring.replicas - 3
+        other_responses = [(404, None, None)] * num_other_resps
+        exc = self._do_test_reconstruct_insufficient_frags(
+            {'quarantine_threshold': 1, 'reclaim_age': 0}, 2, other_responses,
+            local_frag_index=2, frag_index_to_rebuild=3)
+        self.assertIsInstance(exc, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        self._verify_error_lines(2, other_responses, 1)
+
+    def test_reconstruct_fa_no_quarantine_non_404_response(self):
+        num_frags = 1
+        ring = self.policy.object_ring
+        for bad_status in (400, 503, 507):
+            # a non-404 in primary responses will prevent quarantine
+            num_other_resps = ring.replicas - num_frags - 1
+            other_responses = [(404, None, None)] * (num_other_resps - 1)
+            other_responses.append((bad_status, None, None))
+            exc = self._do_test_reconstruct_insufficient_frags(
+                {'quarantine_threshold': 1, 'reclaim_age': 0},
+                num_frags, other_responses)
+            self.assertIsInstance(exc, DiskFileError)
+            self._assert_diskfile_not_quarantined()
+            self._verify_error_lines(num_frags, other_responses, num_frags)
+            warning_lines = self.logger.get_lines_for_level('warning')
+            self.assertEqual(1, len(warning_lines), warning_lines)
+            self.assertIn('Invalid response %s' % bad_status, warning_lines[0])
+
+            # a non-404 in handoff responses will prevent quarantine; non-404
+            # is the *final* handoff response...
+            ring.max_more_nodes = (13 * ring.replicas)
+            for request_node_count in (2, 3, 13):
+                num_other_resps = (request_node_count * ring.replicas
+                                   - num_frags - 1)
+                other_responses = [(404, None, None)] * (num_other_resps - 1)
+                other_responses.append((bad_status, None, None))
+                with annotate_failure(
+                        'request_node_count=%d' % request_node_count):
+                    exc = self._do_test_reconstruct_insufficient_frags(
+                        {'quarantine_threshold': 1,
+                         'reclaim_age': 0,
+                         'request_node_count': '%s * replicas'
+                                               % request_node_count},
+                        num_frags, other_responses)
+                self.assertIsInstance(exc, DiskFileError)
+                self._assert_diskfile_not_quarantined()
+                self._verify_error_lines(num_frags, other_responses, num_frags)
+                warning_lines = self.logger.get_lines_for_level('warning')
+                self.assertEqual(1, len(warning_lines), warning_lines)
+                self.assertIn('Invalid response %s' % bad_status,
+                              warning_lines[0])
+
+            # a non-404 in handoff responses will prevent quarantine; non-404
+            # is part way through all handoffs so not all handoffs are used
+            # regardless of how big request_node_count is
+            non_404_handoff = 3
+            for request_node_count in (2, 3, 13):
+                # replicas - 1 - num_frags other_responses from primaries,
+                # plus a batch of replicas - 1 during which non-404 shows up,
+                # plus some that trickle out before the non-404 shows up, but
+                # limited to (request_node_count * replicas - num_frags - 1)
+                # e.g. for 10+4 policy with request_node_count > 2
+                #   - batch of 13 requests go to primaries,
+                #   - 12 other_responses are consumed,
+                #   - then a batch of 13 handoff requests is sent,
+                #   - the non-404 is the 4th response in that batch,
+                #   - so 3 more requests will have been trickled out
+                batch_size = ring.replicas - 1
+                num_other_resps = min(
+                    2 * batch_size - num_frags + non_404_handoff,
+                    request_node_count * ring.replicas - 1 - num_frags)
+                other_responses = [(404, None, None)] * (num_other_resps - 1)
+                other_responses.insert(
+                    batch_size - num_frags + non_404_handoff,
+                    (bad_status, None, None))
+                exc = self._do_test_reconstruct_insufficient_frags(
+                    {'quarantine_threshold': 1, 'reclaim_age': 0,
+                     'request_node_count': '%s * replicas'
+                                           % request_node_count},
+                    num_frags, other_responses)
+                self.assertIsInstance(exc, DiskFileError)
+                self._assert_diskfile_not_quarantined()
+                self._verify_error_lines(num_frags, other_responses, num_frags)
+                warning_lines = self.logger.get_lines_for_level('warning')
+                self.assertEqual(1, len(warning_lines), warning_lines)
+                self.assertIn('Invalid response %s' % bad_status,
+                              warning_lines[0])
+
+    def test_reconstruct_fa_no_quarantine_frag_not_old_enough(self):
+        # verify that solitary fragment is not quarantined if it has not
+        # reached reclaim_age
+        num_other_resps = self.policy.object_ring.replicas - 2
+        other_responses = [(404, None, None)] * num_other_resps
+        exc = self._do_test_reconstruct_insufficient_frags(
+            {'quarantine_threshold': 1, 'reclaim_age': 10000},
+            1, other_responses)
+        self.assertIsInstance(exc, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        self._verify_error_lines(1, other_responses, 1)
+
+        exc = self._do_test_reconstruct_insufficient_frags(
+            {'quarantine_threshold': 1},  # default reclaim_age
+            1, other_responses)
+        self.assertIsInstance(exc, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        self._verify_error_lines(1, other_responses, 1)
+
+    def test_reconstruct_fa_no_quarantine_frag_resp_different_timestamp(self):
+        # verify that solitary fragment is not quarantined if the only frag
+        # response is for a different timestamp than the local frag
+        resp_timestamp = utils.Timestamp(float(self.obj_timestamp) + 1)
+        num_other_resps = self.policy.object_ring.replicas - 2
+        other_responses = [(404, None, None)] * num_other_resps
+        resp_timestamps = [resp_timestamp] * (num_other_resps + 1)
+        exc = self._do_test_reconstruct_insufficient_frags(
+            {'quarantine_threshold': 1, 'reclaim_age': 0},
+            1, other_responses, resp_timestamps=resp_timestamps)
+        self.assertIsInstance(exc, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        self._verify_error_lines(1, other_responses, 1)
+
+    def test_reconstruct_fa_no_quarantine_frag_resp_mixed_timestamps(self):
+        # verify that solitary fragment is not quarantined if there is a
+        # response for a frag at different timestamp in addition to the
+        # response for the solitary local frag
+        resp_timestamp = utils.Timestamp(float(self.obj_timestamp) + 1)
+        num_other_resps = self.policy.object_ring.replicas - 3
+        other_responses = [(404, None, None)] * num_other_resps
+        resp_timestamps = ([self.obj_timestamp] +
+                           [resp_timestamp] * (num_other_resps + 1))
+        exc = self._do_test_reconstruct_insufficient_frags(
+            {'quarantine_threshold': 1, 'reclaim_age': 0},
+            2, other_responses, resp_timestamps=resp_timestamps)
+        self.assertIsInstance(exc, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        error_lines = self.logger.get_lines_for_level('error')
+        self.assertEqual(3, len(error_lines), error_lines)
+        self.assertIn(
+            'Unable to get enough responses (1/%d from 1 ok responses)'
+            % (self.policy.ec_ndata,), error_lines[0])
+        self.assertIn(
+            'Unable to get enough responses (1/%d from 1 ok responses)'
+            % (self.policy.ec_ndata,), error_lines[1])
+        self.assertIn(
+            'Unable to get enough responses (%d x 404 error responses)'
+            % num_other_resps, error_lines[2])
+
+    def test_reconstruct_fa_no_quarantine_frag_resp_mixed_etags(self):
+        # verify that solitary fragment is not quarantined if there is a
+        # response for a frag with different etag in addition to the
+        # response for the solitary local frag
+        etags = [None, 'unexpected_etag']
+        num_other_resps = self.policy.object_ring.replicas - 3
+        other_responses = [(404, None, None)] * num_other_resps
+        exc = self._do_test_reconstruct_insufficient_frags(
+            {'quarantine_threshold': 1, 'reclaim_age': 0},
+            2, other_responses, resp_etags=etags)
+        self.assertIsInstance(exc, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        error_lines = self.logger.get_lines_for_level('error')
+        self.assertEqual(3, len(error_lines), error_lines)
+        self.assertIn(
+            'Mixed Etag', error_lines[0])
+        self.assertIn(
+            'Unable to get enough responses (1/%d from 2 ok responses)'
+            % (self.policy.ec_ndata,), error_lines[1])
+        self.assertIn(
+            'Unable to get enough responses (%d x 404 error responses)'
+            % num_other_resps, error_lines[2])
+
+    def _do_test_reconstruct_fa_no_quarantine_bad_headers(self, bad_headers):
+        # verify that responses with invalid headers count against the
+        # quarantine_threshold
+        self._configure_reconstructor(reclaim_age=0, quarantine_threshold=1)
+        local_frag_index = 2
+        self._create_fragment(local_frag_index)
+        job = {
+            'partition': 0,
+            'policy': self.policy,
+        }
+        part_nodes = self.policy.object_ring.get_part_nodes(0)
+        node = part_nodes[0]
+        node['backend_index'] = self.policy.get_backend_index(node['index'])
+
+        test_data = (b'rebuild' * self.policy.ec_segment_size)[:-777]
+        etag = md5(test_data, usedforsecurity=False).hexdigest()
+        ec_archive_bodies = encode_frag_archive_bodies(self.policy, test_data)
+
+        def make_header(body):
+            headers = get_header_frag_index(self, body)
+            headers.update({'X-Object-Sysmeta-Ec-Etag': etag})
+            return headers
+
+        responses = []
+        body = ec_archive_bodies[2]
+        headers = make_header(body)
+        responses.append((200, body, headers))
+        body = ec_archive_bodies[3]
+        headers = make_header(body)
+        headers.update(bad_headers)
+        responses.append((200, body, headers))
+        other_responses = ([(404, None, None)] *
+                           (self.policy.object_ring.replicas - 3))
+        codes, body_iter, headers = zip(*(responses + other_responses))
+        resp_timestamps = [self.obj_timestamp] * len(codes)
+        resp_timestamps = [ts.internal for ts in resp_timestamps]
+        with mocked_http_conn(*codes, body_iter=body_iter,
+                              headers=headers,
+                              timestamps=resp_timestamps):
+            with self.assertRaises(DiskFileError) as cm:
+                self.reconstructor.reconstruct_fa(
+                    job, node, self._create_fragment(2))
+        self.assertIsInstance(cm.exception, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        error_lines = self.logger.get_lines_for_level('error')
+        self.assertEqual(2, len(error_lines), error_lines)
+        self.assertIn(
+            'Unable to get enough responses (1/%d from 1 ok responses)'
+            % (self.policy.ec_ndata,), error_lines[0])
+        self.assertIn(
+            'Unable to get enough responses '
+            '(1 x unknown, %d x 404 error responses)'
+            % len(other_responses), error_lines[1])
+
+    def test_reconstruct_fa_no_quarantine_invalid_frag_index_header(self):
+        self._do_test_reconstruct_fa_no_quarantine_bad_headers(
+            {'X-Object-Sysmeta-Ec-Frag-Index': 'two'})
+
+    def test_reconstruct_fa_no_quarantine_missing_frag_index_header(self):
+        self._do_test_reconstruct_fa_no_quarantine_bad_headers(
+            {'X-Object-Sysmeta-Ec-Frag-Index': ''})
+
+    def test_reconstruct_fa_no_quarantine_missing_timestamp_header(self):
+        self._do_test_reconstruct_fa_no_quarantine_bad_headers(
+            {'X-Backend-Data-Timestamp': ''})
+
+    def test_reconstruct_fa_no_quarantine_missing_etag_header(self):
+        self._do_test_reconstruct_fa_no_quarantine_bad_headers(
+            {'X-Object-Sysmeta-Ec-Etag': ''})
+
+    def test_reconstruct_fa_frags_on_handoffs(self):
+        # just a lonely old frag on primaries: this appears to be a quarantine
+        # candidate, but unexpectedly the other frags are found on handoffs so
+        # expect rebuild
+        # set reclaim_age to 0 to make lonely frag old enugh for quarantine
+        self._configure_reconstructor(quarantine_threshold=1, reclaim_age=0)
+        job = {
+            'partition': 0,
+            'policy': self.policy,
+        }
+        part_nodes = self.policy.object_ring.get_part_nodes(0)
+        node = part_nodes[1]
+        node['backend_index'] = self.policy.get_backend_index(node['index'])
+
+        test_data = (b'rebuild' * self.policy.ec_segment_size)[:-777]
+        etag = md5(test_data, usedforsecurity=False).hexdigest()
+        ec_archive_bodies = encode_frag_archive_bodies(self.policy, test_data)
+        broken_body = ec_archive_bodies.pop(1)
+
+        # arrange for just one 200 to come from a primary, then 404s, then 200s
+        # from handoffs
+        responses = list()
+        for i, body in enumerate(ec_archive_bodies):
+            if i == 1:
+                # skip: this is the frag index we're rebuilding; insert 404s
+                responses.extend(
+                    ((404, None, None),) * self.policy.object_ring.replicas)
+            headers = get_header_frag_index(self, body)
+            headers.update({'X-Object-Sysmeta-Ec-Etag': etag})
+            responses.append((200, body, headers))
+
+        codes, body_iter, headers = zip(*responses)
+        with mocked_http_conn(
+                *codes, body_iter=body_iter, headers=headers,
+                timestamps=[self.obj_timestamp.internal] * len(codes)):
+            df = self.reconstructor.reconstruct_fa(
+                job, node, self._create_fragment(0, body=b''))
+            self.assertEqual(0, df.content_length)
+            fixed_body = b''.join(df.reader())
+        self.assertEqual(len(fixed_body), len(broken_body))
+        self.assertEqual(md5(fixed_body, usedforsecurity=False).hexdigest(),
+                         md5(broken_body, usedforsecurity=False).hexdigest())
+        # no error and warning
+        self.assertFalse(self.logger.get_lines_for_level('error'))
+        self.assertFalse(self.logger.get_lines_for_level('warning'))
+        debug_lines = self.logger.get_lines_for_level('debug')
+        self.assertIn('Reconstructing frag from handoffs, node_count=%d'
+                      % (self.policy.object_ring.replicas * 2), debug_lines)
+
     def test_reconstruct_fa_finds_duplicate_does_not_fail(self):
         job = {
             'partition': 0,
@@ -5280,7 +5866,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
         codes, body_iter, headers = zip(*responses)
         with mocked_http_conn(*codes, body_iter=body_iter, headers=headers):
             df = self.reconstructor.reconstruct_fa(
-                job, node, self.obj_metadata)
+                job, node, self._create_fragment(2))
             fixed_body = b''.join(df.reader())
             self.assertEqual(len(fixed_body), len(broken_body))
             self.assertEqual(
@@ -5339,7 +5925,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
             with mocked_http_conn(
                     *codes, body_iter=body_iter, headers=headers) as mock_conn:
                 df = self.reconstructor.reconstruct_fa(
-                    job, node, self.obj_metadata)
+                    job, node, self._create_fragment(2))
                 fixed_body = b''.join(df.reader())
                 self.assertEqual(len(fixed_body), len(broken_body))
                 self.assertEqual(
@@ -5408,7 +5994,7 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
             with mocked_http_conn(
                     *codes, body_iter=body_iter, headers=headers) as mock_conn:
                 df = self.reconstructor.reconstruct_fa(
-                    job, node, self.obj_metadata)
+                    job, node, self._create_fragment(2))
                 fixed_body = b''.join(df.reader())
                 self.assertEqual(len(fixed_body), len(broken_body))
                 self.assertEqual(
@@ -5439,7 +6025,60 @@ class TestReconstructFragmentArchive(BaseTestObjectReconstructor):
 @patch_policies(with_ec_default=True)
 class TestReconstructFragmentArchiveUTF8(TestReconstructFragmentArchive):
     # repeat superclass tests with an object path that contains non-ascii chars
-    obj_path = b'/a/c/o\xc3\xa8'
+    obj_name = b'o\xc3\xa8'
+
+
+@patch_policies([ECStoragePolicy(0, name='ec', is_default=True,
+                                 ec_type=DEFAULT_TEST_EC_TYPE,
+                                 ec_ndata=10, ec_nparity=4,
+                                 ec_segment_size=4096,
+                                 ec_duplication_factor=2),
+                 StoragePolicy(1, name='other')],
+                fake_ring_args=[{'replicas': 28}, {'replicas': 3}])
+class TestReconstructFragmentArchiveECDuplicationFactor(
+        TestReconstructFragmentArchive):
+    def test_reconstruct_fa_no_quarantine_duplicate_frags(self):
+        # verify that quarantine does not happen if the only other response in
+        # addition to the lonely frag's own response is for the same
+        # (duplicate) frag index
+        self._configure_reconstructor(quarantine_threshold=1, reclaim_age=0)
+        local_frag_index = 2
+        self._create_fragment(local_frag_index)
+        job = {
+            'partition': 0,
+            'policy': self.policy,
+        }
+        part_nodes = self.policy.object_ring.get_part_nodes(0)
+        node = part_nodes[0]
+        node['backend_index'] = self.policy.get_backend_index(node['index'])
+
+        test_data = (b'rebuild' * self.policy.ec_segment_size)[:-777]
+        etag = md5(test_data, usedforsecurity=False).hexdigest()
+        ec_archive_bodies = encode_frag_archive_bodies(self.policy, test_data)
+        frags = [
+            ec_archive_bodies[local_frag_index],
+            ec_archive_bodies[local_frag_index +
+                              self.policy.ec_n_unique_fragments]]
+
+        def make_header(body):
+            headers = get_header_frag_index(self, body)
+            headers.update({'X-Object-Sysmeta-Ec-Etag': etag})
+            return headers
+
+        responses = [(200, frag, make_header(frag)) for frag in frags]
+        other_responses = ([(404, None, None)] *
+                           (self.policy.ec_n_unique_fragments * 2 - 3))
+        codes, body_iter, headers = zip(*(responses + other_responses))
+        resp_timestamps = [self.obj_timestamp.internal] * len(codes)
+        with mocked_http_conn(*codes, body_iter=body_iter,
+                              headers=headers,
+                              timestamps=resp_timestamps):
+            with self.assertRaises(DiskFileError) as cm:
+                self.reconstructor.reconstruct_fa(
+                    job, node, self._create_fragment(2))
+        self.assertIsInstance(cm.exception, DiskFileError)
+        self._assert_diskfile_not_quarantined()
+        self._verify_error_lines(2, other_responses, 1)
 
 
 @patch_policies([ECStoragePolicy(0, name='ec', is_default=True,
@@ -5455,6 +6094,13 @@ class TestObjectReconstructorECDuplicationFactor(TestObjectReconstructor):
         self.fabricated_ring = FabricatedRing(replicas=28, devices=56)
 
     def _test_reconstruct_with_duplicate_frags_no_errors(self, index):
+        utils.mkdirs(os.path.join(self.devices, 'sda1'))
+        df_mgr = self.reconstructor._df_router[self.policy]
+        df = df_mgr.get_diskfile('sda1', 9, 'a', 'c', 'o',
+                                 policy=self.policy)
+        write_diskfile(df, self.ts(), data=b'', frag_index=2)
+        df.open()
+
         job = {
             'partition': 0,
             'policy': self.policy,
@@ -5462,12 +6108,6 @@ class TestObjectReconstructorECDuplicationFactor(TestObjectReconstructor):
         part_nodes = self.policy.object_ring.get_part_nodes(0)
         node = part_nodes[index]
         node['backend_index'] = self.policy.get_backend_index(node['index'])
-        metadata = {
-            'name': '/a/c/o',
-            'Content-Length': 0,
-            'ETag': 'etag',
-            'X-Timestamp': '1234567890.12345',
-        }
 
         test_data = (b'rebuild' * self.policy.ec_segment_size)[:-777]
         etag = md5(test_data, usedforsecurity=False).hexdigest()
@@ -5486,9 +6126,9 @@ class TestObjectReconstructorECDuplicationFactor(TestObjectReconstructor):
         called_headers = []
         orig_func = object_reconstructor.ObjectReconstructor._get_response
 
-        def _get_response_hook(self, node, part, path, headers, policy):
+        def _get_response_hook(self, node, policy, part, path, headers):
             called_headers.append(headers)
-            return orig_func(self, node, part, path, headers, policy)
+            return orig_func(self, node, policy, part, path, headers)
 
         # need parity + 1 node failures to reach duplicated fragments
         failed_start_at = (
@@ -5505,7 +6145,7 @@ class TestObjectReconstructorECDuplicationFactor(TestObjectReconstructor):
             with mocked_http_conn(
                     *codes, body_iter=body_iter, headers=headers):
                 df = self.reconstructor.reconstruct_fa(
-                    job, node, metadata)
+                    job, node, df)
                 fixed_body = b''.join(df.reader())
                 self.assertEqual(len(fixed_body), len(broken_body))
                 self.assertEqual(
diff --git a/test/unit/obj/test_ssync.py b/test/unit/obj/test_ssync.py
index 1322e89c32..be98e66f58 100644
--- a/test/unit/obj/test_ssync.py
+++ b/test/unit/obj/test_ssync.py
@@ -16,11 +16,9 @@ from collections import defaultdict
 
 import mock
 import os
-import time
 import unittest
 
 import eventlet
-import itertools
 from six.moves import urllib
 
 from swift.common.exceptions import DiskFileNotExist, DiskFileError, \
@@ -28,8 +26,7 @@ from swift.common.exceptions import DiskFileNotExist, DiskFileError, \
 from swift.common import swob
 from swift.common import utils
 from swift.common.storage_policy import POLICIES, EC_POLICY
-from swift.common.utils import Timestamp
-from swift.obj import ssync_sender, server
+from swift.obj import ssync_sender, server, diskfile
 from swift.obj.reconstructor import RebuildingECDiskFileStream, \
     ObjectReconstructor
 from swift.obj.replicator import ObjectReplicator
@@ -38,7 +35,7 @@ from test import listen_zero
 from test.debug_logger import debug_logger
 from test.unit.obj.common import BaseTest
 from test.unit import patch_policies, encode_frag_archive_bodies, \
-    skip_if_no_xattrs, quiet_eventlet_exceptions
+    skip_if_no_xattrs, quiet_eventlet_exceptions, make_timestamp_iter
 
 
 class TestBaseSsync(BaseTest):
@@ -62,8 +59,7 @@ class TestBaseSsync(BaseTest):
             'log_requests': 'false'}
         self.rx_logger = debug_logger()
         self.rx_controller = server.ObjectController(conf, self.rx_logger)
-        self.ts_iter = (Timestamp(t)
-                        for t in itertools.count(int(time.time())))
+        self.ts_iter = make_timestamp_iter()
         self.rx_ip = '127.0.0.1'
         sock = listen_zero()
         self.rx_server = eventlet.spawn(
@@ -653,11 +649,12 @@ class TestSsyncEC(TestBaseSsyncEC):
 
         reconstruct_fa_calls = []
 
-        def fake_reconstruct_fa(job, node, metadata):
-            reconstruct_fa_calls.append((job, node, policy, metadata))
+        def fake_reconstruct_fa(job, node, df):
+            reconstruct_fa_calls.append((job, node, policy, df))
             if len(reconstruct_fa_calls) == 2:
                 # simulate second reconstruct failing
                 raise DiskFileError
+            metadata = df.get_datafile_metadata()
             content = self._get_object_data(metadata['name'],
                                             frag_index=rx_node_index)
             return RebuildingECDiskFileStream(
@@ -702,7 +699,8 @@ class TestSsyncEC(TestBaseSsyncEC):
 
         # remove the failed df from expected synced df's
         expect_sync_paths = ['/a/c/o1', '/a/c/o2', '/a/c/o3', '/a/c/o5']
-        failed_path = reconstruct_fa_calls[1][3]['name']
+        failed_df = reconstruct_fa_calls[1][3]
+        failed_path = failed_df.get_datafile_metadata()['name']
         expect_sync_paths.remove(failed_path)
         failed_obj = None
         for obj, diskfiles in tx_objs.items():
@@ -843,26 +841,26 @@ class TestSsyncEC(TestBaseSsyncEC):
 
 
 class FakeResponse(object):
-    def __init__(self, frag_index, obj_data, length=None):
-        self.headers = {
-            'X-Object-Sysmeta-Ec-Frag-Index': str(frag_index),
-            'X-Object-Sysmeta-Ec-Etag': 'the etag',
-            'X-Backend-Timestamp': '1234567890.12345'
-        }
+    def __init__(self, frag_index, obj_data, length=None, status=200):
         self.frag_index = frag_index
         self.obj_data = obj_data
         self.data = b''
         self.length = length
-        self.status = 200
+        self.status = status
 
-    def init(self, path):
+    def init(self, path, conf):
         if isinstance(self.obj_data, Exception):
             self.data = self.obj_data
         else:
             self.data = self.obj_data[path][self.frag_index]
+        self.conf = conf
 
     def getheaders(self):
-        return self.headers
+        return {
+            'X-Object-Sysmeta-Ec-Frag-Index': str(self.frag_index),
+            'X-Object-Sysmeta-Ec-Etag': 'the etag',
+            'X-Backend-Timestamp': self.conf['timestamp'].internal
+        }
 
     def read(self, length):
         if isinstance(self.data, Exception):
@@ -878,7 +876,9 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
         self.rx_node_index = 0
         self.tx_node_index = 1
 
-        # create sender side diskfiles...
+        # create sender side diskfiles...ensure their timestamps are in the
+        # past so that tests that set reclaim_age=0 succeed in reclaiming
+        self.ts_iter = make_timestamp_iter(offset=-1000)
         self.tx_objs = {}
         tx_df_mgr = self.daemon._df_router[self.policy]
         t1 = next(self.ts_iter)
@@ -887,6 +887,8 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
         t2 = next(self.ts_iter)
         self.tx_objs['o2'] = self._create_ondisk_files(
             tx_df_mgr, 'o2', self.policy, t2, (self.tx_node_index,))
+        self.response_confs = {'/a/c/o1': {'timestamp': t1},
+                               '/a/c/o2': {'timestamp': t2}}
 
         self.suffixes = set()
         for diskfiles in list(self.tx_objs.values()):
@@ -900,7 +902,7 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
         self.frag_length = int(
             self.tx_objs['o1'][0].get_metadata()['Content-Length'])
 
-    def _test_reconstructor_sync_job(self, frag_responses):
+    def _test_reconstructor_sync_job(self, frag_responses, custom_conf=None):
         # Helper method to mock reconstructor to consume given lists of fake
         # responses while reconstructing a fragment for a sync type job. The
         # tests verify that when the reconstructed fragment iter fails in some
@@ -908,25 +910,31 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
         # node which have incorrect data.
         # See https://bugs.launchpad.net/swift/+bug/1631144
 
+        custom_conf = custom_conf if custom_conf else {}
         # frag_responses is a list of two lists of responses to each
         # reconstructor GET request for a fragment archive. The two items in
         # the outer list are lists of responses for each of the two fragments
-        # to be reconstructed. Items in the inner lists are responses for each
-        # of the other fragments fetched during the reconstructor rebuild.
+        # to be reconstructed, and are used in the order that ssync syncs the
+        # fragments. Items in the inner lists are responses for each of the
+        # other fragments fetched during the reconstructor rebuild.
         path_to_responses = {}
         fake_get_response_calls = []
 
-        def fake_get_response(recon, node, part, path, headers, policy):
+        def fake_get_response(recon, node, policy, part, path, headers):
             # select a list of fake responses for this path and return the next
-            # from the list
+            # from the list: we don't know the order in which paths will show
+            # up but we do want frag_responses[0] to be used first, so the
+            # frag_responses aren't bound to a path until this point
             if path not in path_to_responses:
                 path_to_responses[path] = frag_responses.pop(0)
             response = path_to_responses[path].pop()
-            # the frag_responses list is in ssync task order, we only know the
+            # the frag_responses list is in ssync task order: we only know the
             # path when consuming the responses so initialise the path in the
             # response now
             if response:
-                response.init(path)
+                response.init(path, self.response_confs[path])
+                # should be full path but just used for logging...
+                response.full_path = path
             fake_get_response_calls.append(path)
             return response
 
@@ -944,17 +952,19 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
                 mock.patch.object(
                     self.policy.object_ring, 'get_part_nodes',
                     fake_get_part_nodes):
-            self.reconstructor = ObjectReconstructor(
-                {}, logger=self.logger)
+            conf = self.daemon_conf
+            conf.update(custom_conf)
+            self.reconstructor = ObjectReconstructor(conf, logger=self.logger)
             job = {
                 'device': self.device,
                 'partition': self.partition,
                 'policy': self.policy,
+                'frag_index': self.tx_node_index,
                 'sync_diskfile_builder':
                     self.reconstructor.reconstruct_fa
             }
             sender = ssync_sender.Sender(
-                self.daemon, self.job_node, job, self.suffixes)
+                self.reconstructor, self.job_node, job, self.suffixes)
             sender.connect, trace = self.make_connect_wrapper(sender)
             sender()
         return trace
@@ -975,7 +985,7 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
                 df = self._open_rx_diskfile(
                     obj_name, self.policy, self.rx_node_index)
                 msgs.append('Unexpected rx diskfile for %r with content %r' %
-                            (obj_name, ''.join([d for d in df.reader()])))
+                            (obj_name, b''.join([d for d in df.reader()])))
             except DiskFileNotExist:
                 pass  # expected outcome
         if msgs:
@@ -987,6 +997,7 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
         # trampoline for the receiver to write a log
         eventlet.sleep(0)
         log_lines = self.rx_logger.get_lines_for_level('warning')
+        self.assertEqual(1, len(log_lines), self.rx_logger.all_log_lines())
         self.assertIn('ssync subrequest failed with 499',
                       log_lines[0])
         self.assertFalse(log_lines[1:])
@@ -1009,7 +1020,7 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
                 df = self._open_rx_diskfile(
                     obj_name, self.policy, self.rx_node_index)
                 msgs.append('Unexpected rx diskfile for %r with content %r' %
-                            (obj_name, ''.join([d for d in df.reader()])))
+                            (obj_name, b''.join([d for d in df.reader()])))
             except DiskFileNotExist:
                 pass  # expected outcome
         if msgs:
@@ -1053,7 +1064,7 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
                 df = self._open_rx_diskfile(
                     obj_name, self.policy, self.rx_node_index)
                 msgs.append('Unexpected rx diskfile for %r with content %r' %
-                            (obj_name, ''.join([d for d in df.reader()])))
+                            (obj_name, b''.join([d for d in df.reader()])))
             except DiskFileNotExist:
                 pass  # expected outcome
         if msgs:
@@ -1111,7 +1122,7 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
             df = self._open_rx_diskfile(
                 obj_name, self.policy, self.rx_node_index)
             msgs.append('Unexpected rx diskfile for %r with content %r' %
-                        (obj_name, ''.join([d for d in df.reader()])))
+                        (obj_name, b''.join([d for d in df.reader()])))
         except DiskFileNotExist:
             pass  # expected outcome
         if msgs:
@@ -1123,6 +1134,109 @@ class TestSsyncECReconstructorSyncJob(TestBaseSsyncEC):
         self.assertFalse(self.rx_logger.get_lines_for_level('warning'))
         self.assertFalse(self.rx_logger.get_lines_for_level('error'))
 
+    def test_sync_reconstructor_quarantines_lonely_frag(self):
+        # First fragment to sync gets only one response for reconstructor to
+        # rebuild with, and that response is for the tx_node frag index: it
+        # should be quarantined, but after that the ssync session should still
+        # proceeed with rebuilding the second frag.
+        lonely_frag_responses = [
+            FakeResponse(i, self.obj_data, status=404)
+            for i in range(self.policy.ec_ndata + self.policy.ec_nparity)]
+        lonely_frag_responses[self.tx_node_index].status = 200
+        frag_responses = [
+            lonely_frag_responses,
+            [FakeResponse(i, self.obj_data)
+             for i in range(self.policy.ec_ndata + self.policy.ec_nparity)]]
+
+        # configure reconstructor to quarantine the lonely frag
+        custom_conf = {'reclaim_age': 0, 'quarantine_threshold': 1}
+        trace = self._test_reconstructor_sync_job(frag_responses, custom_conf)
+        results = self._analyze_trace(trace)
+        self.assertEqual(2, len(results['tx_missing']))
+        self.assertEqual(2, len(results['rx_missing']))
+        self.assertEqual(1, len(results['tx_updates']))
+        self.assertFalse(results['rx_updates'])
+        self.assertEqual('PUT', results['tx_updates'][0].get('method'))
+        synced_obj_path = results['tx_updates'][0].get('path')
+        synced_obj_name = synced_obj_path[-2:]
+
+        # verify that the second frag was rebuilt on rx node...
+        msgs = []
+        try:
+            df = self._open_rx_diskfile(
+                synced_obj_name, self.policy, self.rx_node_index)
+            self.assertEqual(
+                self._get_object_data(synced_obj_path,
+                                      frag_index=self.rx_node_index),
+                b''.join([d for d in df.reader()]))
+        except DiskFileNotExist:
+            msgs.append('Missing rx diskfile for %r' % synced_obj_name)
+        # ...and it is still on tx node...
+        try:
+            df = self._open_tx_diskfile(
+                synced_obj_name, self.policy, self.tx_node_index)
+            self.assertEqual(
+                self._get_object_data(df._name,
+                                      frag_index=self.tx_node_index),
+                b''.join([d for d in df.reader()]))
+        except DiskFileNotExist:
+            msgs.append('Missing tx diskfile for %r' % synced_obj_name)
+
+        # verify that the lonely frag was not rebuilt on rx node and was
+        # removed on tx node
+        obj_names = list(self.tx_objs)
+        obj_names.remove(synced_obj_name)
+        quarantined_obj_name = obj_names[0]
+        try:
+            df = self._open_rx_diskfile(
+                quarantined_obj_name, self.policy, self.rx_node_index)
+            msgs.append(
+                'Unexpected rx diskfile for %r with content %r' %
+                (quarantined_obj_name, b''.join([d for d in df.reader()])))
+        except DiskFileNotExist:
+            pass  # expected outcome
+        try:
+            df = self._open_tx_diskfile(
+                quarantined_obj_name, self.policy, self.tx_node_index)
+            msgs.append(
+                'Unexpected tx diskfile for %r with content %r' %
+                (quarantined_obj_name, b''.join([d for d in df.reader()])))
+        except DiskFileNotExist:
+            pass  # expected outcome
+
+        if msgs:
+            self.fail('Failed with:\n%s' % '\n'.join(msgs))
+        error_lines = self.logger.get_lines_for_level('error')
+        self.assertEqual(2, len(error_lines), error_lines)
+        self.assertIn('Unable to get enough responses', error_lines[0])
+        self.assertIn('Unable to get enough responses', error_lines[1])
+        warning_lines = self.logger.get_lines_for_level('warning')
+        self.assertEqual(1, len(warning_lines), warning_lines)
+        self.assertIn('Quarantined object', warning_lines[0])
+
+        # check we have a quarantined data file
+        df_mgr = self.daemon._df_router[self.policy]
+        quarantined_df = df_mgr.get_diskfile(
+            self.device, self.partition, account='a', container='c',
+            obj=quarantined_obj_name, policy=self.policy,
+            frag_index=self.tx_node_index)
+        df_hash = os.path.basename(quarantined_df._datadir)
+        quarantine_dir = os.path.join(
+            quarantined_df._device_path, 'quarantined',
+            diskfile.get_data_dir(self.policy), df_hash)
+        self.assertTrue(os.path.isdir(quarantine_dir))
+        data_file = os.listdir(quarantine_dir)[0]
+        with open(os.path.join(quarantine_dir, data_file), 'rb') as fd:
+            self.assertEqual(
+                self._get_object_data(quarantined_df._name,
+                                      frag_index=self.tx_node_index),
+                fd.read())
+
+        # trampoline for the receiver to write a log
+        eventlet.sleep(0)
+        self.assertFalse(self.rx_logger.get_lines_for_level('warning'))
+        self.assertFalse(self.rx_logger.get_lines_for_level('error'))
+
     def test_sync_reconstructor_rebuild_ok(self):
         # Sanity test for this class of tests. Both fragments get a full
         # complement of responses and rebuild correctly.
diff --git a/test/unit/proxy/test_server.py b/test/unit/proxy/test_server.py
index e8f7eef532..ee25376b83 100644
--- a/test/unit/proxy/test_server.py
+++ b/test/unit/proxy/test_server.py
@@ -4699,10 +4699,30 @@ class TestReplicatedObjectController(
             self.assertEqual(resp.status_int, 503)
 
     def test_node_request_setting(self):
-        baseapp = proxy_server.Application({'request_node_count': '3'},
+        # default is 2 * replicas
+        baseapp = proxy_server.Application({},
                                            container_ring=FakeRing(),
                                            account_ring=FakeRing())
-        self.assertEqual(baseapp.request_node_count(3), 3)
+        self.assertEqual(6, baseapp.request_node_count(3))
+
+        def do_test(value, replicas, expected):
+            baseapp = proxy_server.Application({'request_node_count': value},
+                                               container_ring=FakeRing(),
+                                               account_ring=FakeRing())
+            self.assertEqual(expected, baseapp.request_node_count(replicas))
+
+        do_test('3', 4, 3)
+        do_test('1 * replicas', 4, 4)
+        do_test('2 * replicas', 4, 8)
+        do_test('4', 4, 4)
+        do_test('5', 4, 5)
+
+        for bad in ('1.1', 1.1, 'auto', 'bad',
+                    '2.5 * replicas', 'two * replicas'):
+            with self.assertRaises(ValueError):
+                proxy_server.Application({'request_node_count': bad},
+                                         container_ring=FakeRing(),
+                                         account_ring=FakeRing())
 
     def test_iter_nodes(self):
         with save_globals():