1 files changed, 15 insertions, 4 deletions
diff --git a/qpid/cpp/xml/cluster.xml b/qpid/cpp/xml/cluster.xml
index d9ab6e97cb..474c191b0b 100644
--- a/qpid/cpp/xml/cluster.xml
+++ b/qpid/cpp/xml/cluster.xml
@@ -27,16 +27,24 @@
   <class name = "cluster" code = "0x80" label="Qpid clustering extensions.">
     <doc>Qpid extension class to allow clustered brokers to communicate.</doc>
 
-    <control name="update-request" code="0x1" label="URL for a member.">
+    <!-- New joiner requests an update to url. -->
+    <control name="update-request" code="0x1">
       <field name="url" type="str16"/>
     </control>
 
-    <control name = "update-offer" code="0x2" label="Member offering to be updater for updatee.">
+    <!-- Sender offers an update to a new joiner. -->
+    <control name = "update-offer" code="0x2">
       <field name="updatee" type="uint64"/>
       <field name="cluster-id" type="uuid"/>
     </control>
 
-    <control name="ready" code="0x10" label="New member is ready.">
+    <!-- Sender retracts an offer to a new joiner. -->
+    <control name = "retract-offer" code="0x3">
+      <field name="updatee" type="uint64"/>
+    </control>
+
+    <!-- New member or updater is ready as an active member. -->
+    <control name="ready" code="0x10">
       <field name="url" type="str16"/>
     </control>
 
@@ -91,7 +99,7 @@
 	 - attach sessions, create consumers, set flow with normal AMQP cokmmands.
 	 - send /reset additional session state with controls below.
 	 - send shadow-ready to mark end of shadow update.
-	 - send update-complete when entire update is complete.
+	 - send membership when entire update is complete.
     -->
     
     <!-- Consumer state that cannot be set by standard AMQP controls. -->
@@ -166,6 +174,9 @@
       <field name="frame-seq" type="uint64"/>	 <!-- frame sequence number -->
     </control>
 
+    <!-- Updater cannot fulfill an update offer. -->
+    <control name = "retract-offer" code="0x22"/>
+
     <!-- Set the position of a replicated queue. -->
     <control name="queue-position" code="0x30">
       <field name="queue" type="str8"/>