Only raise EtcdClusterIdChanged on first request after change.

2 files changed, 25 insertions, 12 deletions

diff --git a/src/etcd/client.py b/src/etcd/client.py
index 809b4a9..3a7e3ca 100644
--- a/src/etcd/client.py
+++ b/src/etcd/client.py
@@ -624,18 +624,21 @@ class Client(object):
                 some_request_failed = True
 
             else:
-                # Check the cluster ID hasn't changed under us.
-                # We need preload_content == False above to ensure we can read
-                # the headers here before waiting for the content of a watch
-                # below.
+                # Check the cluster ID hasn't changed under us.  We use
+                # preload_content=False above so we can read the headers
+                # before we wait for the content of a long poll.
                 cluster_id = response.getheader("x-etcd-cluster-id")
-                if self.expected_cluster_id:
-                    if self.expected_cluster_id != cluster_id:
-                        raise etcd.EtcdClusterIdChanged(
-                            'The UUID of the cluster changed from {} to '
-                            '{}.'.format(self.expected_cluster_id, cluster_id))
-                else:
-                    self.expected_cluster_id = cluster_id
+                id_changed = (self.expected_cluster_id and
+                              cluster_id != self.expected_cluster_id)
+                # Update the ID so we only raise the exception once.
+                self.expected_cluster_id = cluster_id
+                if id_changed:
+                    # Defensive: clear the pool so that we connect afresh next
+                    # time.
+                    self.http.clear()
+                    raise etcd.EtcdClusterIdChanged(
+                        'The UUID of the cluster changed from {} to '
+                        '{}.'.format(self.expected_cluster_id, cluster_id))
 
         if some_request_failed:
             if not self._use_proxies:
diff --git a/src/etcd/tests/unit/test_request.py b/src/etcd/tests/unit/test_request.py
index 23a5690..2f36168 100644
--- a/src/etcd/tests/unit/test_request.py
+++ b/src/etcd/tests/unit/test_request.py
@@ -513,9 +513,19 @@ class TestClientRequest(TestClientApiInterface):
 
     def test_read_cluster_id_changed(self):
         """ Read timeout set to the default """
-        self._mock_api(200, {}, cluster_id="notabcd1234")
+        d = {u'action': u'set',
+             u'node': {
+                u'expiration': u'2013-09-14T00:56:59.316195568+02:00',
+                u'modifiedIndex': 6,
+                u'key': u'/testkey',
+                u'ttl': 19,
+                u'value': u'test'
+                }
+             }
+        self._mock_api(200, d, cluster_id="notabcd1234")
         self.assertRaises(etcd.EtcdClusterIdChanged,
                           self.client.read, '/testkey')
+        self.client.read("/testkey")
 
     def test_not_in(self):
         pass