diff --git a/tests/utests/common/__init__.py b/tests/utests/common/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/utests/common/__init__.py
diff --git a/tests/utests/common/test_event_bus.py b/tests/utests/common/test_event_bus.py
new file mode 100644
index 0000000..532befb
--- /dev/null
+++ b/tests/utests/common/test_event_bus.py
@@ -0,0 +1,197 @@
+#
+# Copyright 2016 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+import re
+
+from mock import Mock
+from mock import call
+from twisted.internet.defer import DeferredQueue, inlineCallbacks
+from twisted.trial.unittest import TestCase
+
+from common.event_bus import EventBusClient, EventBus
+
+
+class TestEventBus(TestCase):
+
+    def test_subscribe(self):
+
+        ebc = EventBusClient()
+        sub = ebc.subscribe('news', lambda msg, topic: None)
+        self.assertEqual(len(ebc.list_subscribers()), 1)
+        self.assertEqual(len(ebc.list_subscribers('news')), 1)
+        self.assertEqual(len(ebc.list_subscribers('other')), 0)
+
+    def test_unsubscribe(self):
+
+        ebc = EventBusClient(EventBus())
+        sub = ebc.subscribe('news', lambda msg, topic: None)
+        ebc.unsubscribe(sub)
+        self.assertEqual(ebc.list_subscribers(), [])
+        self.assertEqual(ebc.list_subscribers('news'), [])
+
+    def test_simple_publish(self):
+
+        ebc = EventBusClient(EventBus())
+
+        mock = Mock()
+        ebc.subscribe('news', mock)
+
+        ebc.publish('news', 'message')
+
+        self.assertEqual(mock.call_count, 1)
+        mock.assert_called_with('news', 'message')
+
+    def test_topic_filtering(self):
+
+        ebc = EventBusClient(EventBus())
+
+        mock = Mock()
+        ebc.subscribe('news', mock)
+
+        ebc.publish('news', 'msg1')
+        ebc.publish('alerts', 'msg2')
+        ebc.publish('logs', 'msg3')
+
+        self.assertEqual(mock.call_count, 1)
+        mock.assert_called_with('news', 'msg1')
+
+    def test_multiple_subscribers(self):
+
+        ebc = EventBusClient(EventBus())
+
+        mock1 = Mock()
+        ebc.subscribe('news', mock1)
+
+        mock2 = Mock()
+        ebc.subscribe('alerts', mock2)
+
+        mock3 = Mock()
+        ebc.subscribe('logs', mock3)
+
+        mock4 = Mock()
+        ebc.subscribe('logs', mock4)
+
+        ebc.publish('news', 'msg1')
+        ebc.publish('alerts', 'msg2')
+        ebc.publish('logs', 'msg3')
+
+        self.assertEqual(mock1.call_count, 1)
+        mock1.assert_called_with('news', 'msg1')
+
+        self.assertEqual(mock2.call_count, 1)
+        mock2.assert_called_with('alerts', 'msg2')
+
+        self.assertEqual(mock3.call_count, 1)
+        mock3.assert_called_with('logs', 'msg3')
+
+        self.assertEqual(mock4.call_count, 1)
+        mock4.assert_called_with('logs', 'msg3')
+
+    def test_predicates(self):
+
+        ebc = EventBusClient(EventBus())
+
+        get_foos = Mock()
+        ebc.subscribe('', get_foos, lambda msg: msg.startswith('foo'))
+
+        get_bars = Mock()
+        ebc.subscribe('', get_bars, lambda msg: msg.endswith('bar'))
+
+        get_all = Mock()
+        ebc.subscribe('', get_all)
+
+        get_none = Mock()
+        ebc.subscribe('', get_none, lambda msg: msg.find('zoo') >= 0)
+
+        errored = Mock()
+        ebc.subscribe('', errored, lambda msg: 1/0)
+
+        ebc.publish('', 'foo')
+        ebc.publish('', 'foobar')
+        ebc.publish('', 'bar')
+
+        c = call
+
+        self.assertEqual(get_foos.call_count, 2)
+        get_foos.assert_has_calls([c('', 'foo'), c('', 'foobar')])
+
+        self.assertEqual(get_bars.call_count, 2)
+        get_bars.assert_has_calls([c('', 'foobar'), c('', 'bar')])
+
+        self.assertEqual(get_all.call_count, 3)
+        get_all.assert_has_calls([c('', 'foo'), c('', 'foobar'), c('', 'bar')])
+
+        get_none.assert_not_called()
+
+        errored.assert_not_called()
+
+    def test_wildcard_topic(self):
+
+        ebc = EventBusClient(EventBus())
+        subs = []
+
+        wildcard_sub = Mock()
+        subs.append(ebc.subscribe(re.compile(r'.*'), wildcard_sub))
+
+        prefix_sub = Mock()
+        subs.append(ebc.subscribe(re.compile(r'ham.*'), prefix_sub))
+
+        contains_sub = Mock()
+        subs.append(ebc.subscribe(re.compile(r'.*burg.*'), contains_sub))
+
+        ebc.publish('news', 1)
+        ebc.publish('hamsters', 2)
+        ebc.publish('hamburgers', 3)
+        ebc.publish('nonsense', 4)
+
+        c = call
+
+        self.assertEqual(wildcard_sub.call_count, 4)
+        wildcard_sub.assert_has_calls([
+            c('news', 1),
+            c('hamsters', 2),
+            c('hamburgers', 3),
+            c('nonsense', 4)])
+
+        self.assertEqual(prefix_sub.call_count, 2)
+        prefix_sub.assert_has_calls([
+            c('hamsters', 2),
+            c('hamburgers', 3)])
+
+        self.assertEqual(contains_sub.call_count, 1)
+        contains_sub.assert_has_calls([c('hamburgers', 3)])
+
+        for sub in subs:
+            ebc.unsubscribe(sub)
+
+        self.assertEqual(ebc.list_subscribers(), [])
+
+    @inlineCallbacks
+    def test_deferred_queue_receiver(self):
+
+        ebc = EventBus()
+
+        queue = DeferredQueue()
+
+        ebc.subscribe('', lambda _, msg: queue.put(msg))
+
+        for i in xrange(10):
+            ebc.publish('', i)
+
+        self.assertEqual(len(queue.pending), 10)
+        for i in xrange(10):
+            msg = yield queue.get()
+            self.assertEqual(msg, i)
+        self.assertEqual(len(queue.pending), 0)