add ignore_cluster_errors params

Author: opapy

README.rst

@@ -52,6 +52,7 @@ Your cache backend should look something like this::
             'OPTIONS': {
               'cluster_timeout': 1, # its used when get cluster info
               'ignore_exc': True, # pymemcache Client params
+              'ignore_cluster_errors': True, # ignore get cluster info error
             }
         }
     }

django_elastipymemcache/cluster_utils.py

@@ -19,7 +19,7 @@ def __init__(self, cmd, response):
             'Unexpected response {} for command {}'.format(response, cmd))
 
 
-def get_cluster_info(host, port, timeout=socket._GLOBAL_DEFAULT_TIMEOUT):
+def get_cluster_info(host, port, ignore_cluster_errors=False, timeout=socket._GLOBAL_DEFAULT_TIMEOUT):
     """
     return dict with info about nodes in cluster and current version
     {
@@ -48,6 +48,14 @@ def get_cluster_info(host, port, timeout=socket._GLOBAL_DEFAULT_TIMEOUT):
     ])
     client.close()
 
+    if res == b'ERROR\r\n' and ignore_cluster_errors:
+        return {
+            'version': version,
+            'nodes': [
+                (smart_text(host), int(port))
+            ]
+        }
+
     ls = list(filter(None, re.compile(br'\r?\n').split(res)))
     if len(ls) != 4:
         raise WrongProtocolData(cmd, res)

django_elastipymemcache/memcached.py

@@ -70,6 +70,8 @@ def __init__(self, server, params):
         self._options = self._options or dict()
         self._cluster_timeout = self._options.get(
                 'cluster_timeout', socket._GLOBAL_DEFAULT_TIMEOUT)
+        self._ignore_cluster_errors = self._options.get(
+                'ignore_cluster_errors', False)
 
     def clear_cluster_nodes_cache(self):
         """clear internal cache with list of nodes in cluster"""
@@ -85,6 +87,7 @@ def get_cluster_nodes(self):
             return get_cluster_info(
                 server,
                 port,
+                self._ignore_cluster_errors,
                 self._cluster_timeout
             )['nodes']
         except (OSError, socket.gaierror, socket.timeout) as err:
@@ -105,6 +108,7 @@ def _cache(self):
             options['deserializer'] = deserialize_pickle
             options.setdefault('ignore_exc', True)
             options.pop('cluster_timeout', None)
+            options.pop('ignore_cluster_errors', None)
 
             self._client = self._lib.Client(
                 self.get_cluster_nodes(), **options)