diff --git a/marconi/openstack/common/cache/_backends/memory.py b/marconi/openstack/common/cache/_backends/memory.py
index 1c3b0b21c..0f2d52ee2 100644
--- a/marconi/openstack/common/cache/_backends/memory.py
+++ b/marconi/openstack/common/cache/_backends/memory.py
@@ -147,7 +147,7 @@ class MemoryBackend(backends.BaseCache):
             try:
                 # NOTE(flaper87): Keys with ttl == 0
                 # don't exist in the _keys_expires dict
-                self._keys_expires[value[0]].remove(value[1])
+                self._keys_expires[value[0]].remove(key)
             except (KeyError, ValueError):
                 pass
 
diff --git a/marconi/openstack/common/cache/backends.py b/marconi/openstack/common/cache/backends.py
index 2fa4aaeb2..1bea8912a 100644
--- a/marconi/openstack/common/cache/backends.py
+++ b/marconi/openstack/common/cache/backends.py
@@ -26,9 +26,9 @@ class BaseCache(object):
 
     :params parsed_url: Parsed url object.
     :params options: A dictionary with configuration parameters
-        for the cache. For example:
-            - default_ttl: An integer defining the default ttl
-            for keys.
+      for the cache. For example:
+
+        - default_ttl: An integer defining the default ttl for keys.
     """
 
     def __init__(self, parsed_url, options=None):
@@ -43,20 +43,17 @@ class BaseCache(object):
     def set(self, key, value, ttl, not_exists=False):
         """Sets or updates a cache entry
 
-        NOTE: Thread-safety is required and has to be
-        guaranteed by the backend implementation.
+        .. note:: Thread-safety is required and has to be guaranteed by the
+           backend implementation.
 
         :params key: Item key as string.
         :type key: `unicode string`
-        :params value: Value to assign to the key. This
-                       can be anything that is handled
-                       by the current backend.
-        :params ttl: Key's timeout in seconds. 0 means
-                     no timeout.
+        :params value: Value to assign to the key. This can be anything that
+          is handled by the current backend.
+        :params ttl: Key's timeout in seconds. 0 means no timeout.
         :type ttl: int
-        :params not_exists: If True, the key will be set
-                            if it doesn't exist. Otherwise,
-                            it'll always be set.
+        :params not_exists: If True, the key will be set if it doesn't exist.
+          Otherwise, it'll always be set.
         :type not_exists: bool
 
         :returns: True if the operation succeeds, False otherwise.
@@ -74,9 +71,8 @@ class BaseCache(object):
 
         :params key: Item key as string.
         :type key: `unicode string`
-        :params value: Value to assign to the key. This
-                       can be anything that is handled
-                       by the current backend.
+        :params value: Value to assign to the key. This can be anything that
+          is handled by the current backend.
         """
         try:
             return self[key]
@@ -91,15 +87,14 @@ class BaseCache(object):
     def get(self, key, default=None):
         """Gets one item from the cache
 
-        NOTE: Thread-safety is required and it has to be
-        guaranteed by the backend implementation.
+        .. note:: Thread-safety is required and it has to be guaranteed
+           by the backend implementation.
 
-        :params key: Key for the item to retrieve
-                     from the cache.
+        :params key: Key for the item to retrieve from the cache.
         :params default: The default value to return.
 
-        :returns: `key`'s value in the cache if it exists,
-                  otherwise `default` should be returned.
+        :returns: `key`'s value in the cache if it exists, otherwise
+          `default` should be returned.
         """
         return self._get(key, default)
 
@@ -115,8 +110,8 @@ class BaseCache(object):
     def __delitem__(self, key):
         """Removes an item from cache.
 
-        NOTE: Thread-safety is required and it has to be
-        guaranteed by the backend implementation.
+        .. note:: Thread-safety is required and it has to be guaranteed by
+           the backend implementation.
 
         :params key: The key to remove.
 
@@ -130,8 +125,8 @@ class BaseCache(object):
     def clear(self):
         """Removes all items from the cache.
 
-        NOTE: Thread-safety is required and it has to be
-        guaranteed by the backend implementation.
+        .. note:: Thread-safety is required and it has to be guaranteed by
+           the backend implementation.
         """
         return self._clear()
 
@@ -143,9 +138,8 @@ class BaseCache(object):
         """Increments the value for a key
 
         :params key: The key for the value to be incremented
-        :params delta: Number of units by which to increment
-                       the value. Pass a negative number to
-                       decrement the value.
+        :params delta: Number of units by which to increment the value.
+          Pass a negative number to decrement the value.
 
         :returns: The new value
         """
@@ -158,10 +152,8 @@ class BaseCache(object):
     def append_tail(self, key, tail):
         """Appends `tail` to `key`'s value.
 
-        :params key: The key of the value to which
-                     `tail` should be appended.
-        :params tail: The list of values to append to the
-                      original.
+        :params key: The key of the value to which `tail` should be appended.
+        :params tail: The list of values to append to the original.
 
         :returns: The new value
         """
@@ -181,10 +173,8 @@ class BaseCache(object):
     def append(self, key, value):
         """Appends `value` to `key`'s value.
 
-        :params key: The key of the value to which
-                     `tail` should be appended.
-        :params value: The value to append to the
-                      original.
+        :params key: The key of the value to which `tail` should be appended.
+        :params value: The value to append to the original.
 
         :returns: The new value
         """
@@ -196,8 +186,7 @@ class BaseCache(object):
 
         :params key: The key to verify.
 
-        :returns: True if the key exists,
-                  otherwise False.
+        :returns: True if the key exists, otherwise False.
         """
 
     @abc.abstractmethod
@@ -209,9 +198,8 @@ class BaseCache(object):
         """Gets keys' value from cache
 
         :params keys: List of keys to retrieve.
-        :params default: The default value to return
-                         for each key that is not in
-                         the cache.
+        :params default: The default value to return for each key that is not
+          in the cache.
 
         :returns: A  generator of (key, value)
         """
@@ -227,13 +215,12 @@ class BaseCache(object):
     def set_many(self, data, ttl=None):
         """Puts several items into the cache at once
 
-        Depending on the backend, this operation may or may
-        not be efficient. The default implementation calls
-        set for each (key, value) pair passed, other backends
-        support set_many operations as part of their protocols.
+        Depending on the backend, this operation may or may not be efficient.
+        The default implementation calls set for each (key, value) pair
+        passed, other backends support set_many operations as part of their
+        protocols.
 
-        :params data: A dictionary like {key: val} to store
-                      in the cache.
+        :params data: A dictionary like {key: val} to store in the cache.
         :params ttl: Key's timeout in seconds.
         """
 
diff --git a/marconi/openstack/common/config/generator.py b/marconi/openstack/common/config/generator.py
index aa532a550..f302a5726 100644
--- a/marconi/openstack/common/config/generator.py
+++ b/marconi/openstack/common/config/generator.py
@@ -64,6 +64,10 @@ BASEDIR = os.path.abspath(os.path.join(os.path.dirname(__file__),
 WORDWRAP_WIDTH = 60
 
 
+def raise_extension_exception(extmanager, ep, err):
+    raise
+
+
 def generate(argv):
     parser = argparse.ArgumentParser(
         description='generate sample configuration file',
@@ -107,6 +111,7 @@ def generate(argv):
             'oslo.config.opts',
             names=list(set(parsed_args.libraries)),
             invoke_on_load=False,
+            on_load_failure_callback=raise_extension_exception
         )
         for ext in loader:
             for group, opts in ext.plugin():
@@ -145,7 +150,7 @@ def _import_module(mod_str):
 
 
 def _is_in_group(opt, group):
-    "Check if opt is in group."
+    """Check if opt is in group."""
     for value in group._opts.values():
         # NOTE(llu): Temporary workaround for bug #1262148, wait until
         # newly released oslo.config support '==' operator.
@@ -154,7 +159,7 @@ def _is_in_group(opt, group):
     return False
 
 
-def _guess_groups(opt, mod_obj):
+def _guess_groups(opt):
     # is it in the DEFAULT group?
     if _is_in_group(opt, cfg.CONF):
         return 'DEFAULT'
@@ -188,7 +193,7 @@ def _list_opts(obj):
 
     ret = {}
     for opt in opts:
-        ret.setdefault(_guess_groups(opt, obj), []).append(opt)
+        ret.setdefault(_guess_groups(opt), []).append(opt)
     return ret.items()
 
 
@@ -218,6 +223,8 @@ def _get_my_ip():
 
 def _sanitize_default(name, value):
     """Set up a reasonably sensible default for pybasedir, my_ip and host."""
+    hostname = socket.gethostname()
+    fqdn = socket.getfqdn()
     if value.startswith(sys.prefix):
         # NOTE(jd) Don't use os.path.join, because it is likely to think the
         # second part is an absolute pathname and therefore drop the first
@@ -229,8 +236,13 @@ def _sanitize_default(name, value):
         return value.replace(BASEDIR, '')
     elif value == _get_my_ip():
         return '10.0.0.1'
-    elif value in (socket.gethostname(), socket.getfqdn()) and 'host' in name:
-        return 'marconi'
+    elif value in (hostname, fqdn):
+        if 'host' in name:
+            return 'marconi'
+    elif value.endswith(hostname):
+        return value.replace(hostname, 'marconi')
+    elif value.endswith(fqdn):
+        return value.replace(fqdn, 'marconi')
     elif value.strip() != value:
         return '"%s"' % value
     return value
@@ -241,7 +253,6 @@ def _print_opt(opt):
     if not opt_help:
         sys.stderr.write('WARNING: "%s" is missing help string.\n' % opt_name)
         opt_help = ""
-    opt_type = None
     try:
         opt_type = OPTION_REGEX.search(str(type(opt))).group(0)
     except (ValueError, AttributeError) as err:
diff --git a/marconi/openstack/common/excutils.py b/marconi/openstack/common/excutils.py
index c0817428d..3d7c3002f 100644
--- a/marconi/openstack/common/excutils.py
+++ b/marconi/openstack/common/excutils.py
@@ -49,9 +49,22 @@ class save_and_reraise_exception(object):
               decide_if_need_reraise()
               if not should_be_reraised:
                   ctxt.reraise = False
+
+    If another exception occurs and reraise flag is False,
+    the saved exception will not be logged.
+
+    If the caller wants to raise new exception during exception handling
+    he/she sets reraise to False initially with an ability to set it back to
+    True if needed::
+
+      except Exception:
+          with save_and_reraise_exception(reraise=False) as ctxt:
+              [if statements to determine whether to raise a new exception]
+              # Not raising a new exception, so reraise
+              ctxt.reraise = True
     """
-    def __init__(self):
-        self.reraise = True
+    def __init__(self, reraise=True):
+        self.reraise = reraise
 
     def __enter__(self):
         self.type_, self.value, self.tb, = sys.exc_info()
@@ -59,10 +72,11 @@ class save_and_reraise_exception(object):
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         if exc_type is not None:
-            logging.error(_LE('Original exception being dropped: %s'),
-                          traceback.format_exception(self.type_,
-                                                     self.value,
-                                                     self.tb))
+            if self.reraise:
+                logging.error(_LE('Original exception being dropped: %s'),
+                              traceback.format_exception(self.type_,
+                                                         self.value,
+                                                         self.tb))
             return False
         if self.reraise:
             six.reraise(self.type_, self.value, self.tb)
diff --git a/marconi/openstack/common/fileutils.py b/marconi/openstack/common/fileutils.py
index b7c2285ab..bbf445e39 100644
--- a/marconi/openstack/common/fileutils.py
+++ b/marconi/openstack/common/fileutils.py
@@ -99,13 +99,13 @@ def remove_path_on_error(path, remove=delete_if_exists):
 def file_open(*args, **kwargs):
     """Open file
 
-    see built-in file() documentation for more details
+    see built-in open() documentation for more details
 
     Note: The reason this is kept in a separate module is to easily
     be able to provide a stub module that doesn't alter system
     state at all (for unit tests)
     """
-    return file(*args, **kwargs)
+    return open(*args, **kwargs)
 
 
 def write_to_tempfile(content, path=None, suffix='', prefix='tmp'):
diff --git a/marconi/openstack/common/lockutils.py b/marconi/openstack/common/lockutils.py
index 963dd5705..65e0b86ef 100644
--- a/marconi/openstack/common/lockutils.py
+++ b/marconi/openstack/common/lockutils.py
@@ -38,10 +38,10 @@ LOG = logging.getLogger(__name__)
 
 util_opts = [
     cfg.BoolOpt('disable_process_locking', default=False,
-                help='Whether to disable inter-process locks'),
+                help='Enables or disables inter-process locks.'),
     cfg.StrOpt('lock_path',
                default=os.environ.get("MARCONI_LOCK_PATH"),
-               help=('Directory to use for lock files.'))
+               help='Directory to use for lock files.')
 ]
 
 
@@ -239,7 +239,7 @@ def external_lock(name, lock_file_prefix=None, lock_path=None):
 
 
 def remove_external_lock_file(name, lock_file_prefix=None):
-    """Remove a external lock file when it's not used anymore
+    """Remove an external lock file when it's not used anymore
     This will be helpful when we have a lot of lock files
     """
     with internal_lock(name):
@@ -276,7 +276,7 @@ def lock(name, lock_file_prefix=None, external=False, lock_path=None):
 
     :param external: The external keyword argument denotes whether this lock
       should work across multiple processes. This means that if two different
-      workers both run a a method decorated with @synchronized('mylock',
+      workers both run a method decorated with @synchronized('mylock',
       external=True), only one of them will execute at a time.
     """
     int_lock = internal_lock(name)
@@ -287,6 +287,7 @@ def lock(name, lock_file_prefix=None, external=False, lock_path=None):
                 yield ext_lock
         else:
             yield int_lock
+    LOG.debug('Released semaphore "%(lock)s"', {'lock': name})
 
 
 def synchronized(name, lock_file_prefix=None, external=False, lock_path=None):