订阅NServiceBus 2.5端点从NServiceBus 4.7.5端点发布的消息

Question

我有两个端点，一个是NSB 2.5并发布消息，另一个是NSB 4.7.5。我想在我的NSB4端点中订阅NSB2发布的事件，但是当我将订阅添加到NSB4端点时，我在NSB2端点中收到以下错误：

System.Xml.XmlException: Root element is missing.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.ThrowWithoutLineInfo(String res)
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.XmlLoader.Load(XmlDocument doc, XmlReader reader, Boolean preserveWhitespace)
   at System.Xml.XmlDocument.Load(XmlReader reader)
   at NServiceBus.Serializers.XML.MessageSerializer.Deserialize(Stream stream) in c:devv3NServiceBussrcimplSeri
   at NServiceBus.Unicast.Transport.Msmq.MsmqTransport.Extract(Message message) in c:devv3NServiceBussrcimpluni
   at NServiceBus.Unicast.Transport.Msmq.MsmqTransport.ReceiveFromQueue() in c:devv3NServiceBussrcimplunicastN

以及我的NSB2错误队列中的以下内容：

<?xml version="1.0"?>
<ArrayOfHeaderInfo xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <HeaderInfo>
    <Key>NServiceBus.MessageId</Key>
    <Value>7ffbe1e3-9b2c-456c-bcb7-a43d011a2389</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>NServiceBus.CorrelationId</Key>
    <Value>7ffbe1e3-9b2c-456c-bcb7-a43d011a2389</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>NServiceBus.OriginatingEndpoint</Key>
    <Value>NSB4Client</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>$.diagnostics.originating.hostid</Key>
    <Value>75e8656bb268f44ded5f2a82b8798e6a</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>NServiceBus.MessageIntent</Key>
    <Value>Subscribe</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>NServiceBus.Version</Key>
    <Value>4.7.5</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>NServiceBus.TimeSent</Key>
    <Value>2015-02-12 17:07:14:158882 Z</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>NServiceBus.OriginatingMachine</Key>
    <Value>xxx</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>NServiceBus.ControlMessage</Key>
    <Value>True</Value>
  </HeaderInfo>
  <HeaderInfo>
    <Key>SubscriptionMessageType</Key>
    <Value>MyMessages.EventMessage, MyMessages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null</Value>
  </HeaderInfo>
</ArrayOfHeaderInfo>

我假设这是因为标头在4和2之间不兼容，在这种情况下，我应该能够使用变异器转换为兼容的格式，尽管我尝试使用变异器拦截NSB4端点上的传出消息，但它似乎没有拦截消息（同时使用IMutateTransportMessages和IMutateMessages）

更新2015-02-16根据https://groups.google.com/forum/#！topic/speculatorsoftware/XVLQkCouKCk这将解释为什么我的传出突变器解决方案不工作

Answer 1

V2.5期望消息被封装在根节点中，即使只有一条消息被发送。该设置在v4中默认情况下处于禁用状态。

通过调用打开它

https://github.com/Particular/NServiceBus/blob/4.7.5/src/NServiceBus.Core/Settings/SerializationSettings.cs#L11