Short tutorial on WS-RM

WS-Reliable Messaging( or WS-RM for short) is specification that defines reliable message delivery of between components.

When a WS-RM client talks to a WS-RM enable server there are three messages that goes between them. First the client requests the server with a WS-RM create sequence first try to create a sequence by sending a message with CreateSequence element. This is to initiate a WS-RM session and the request looks like below (note the SOAP body).

<?xml version='1.0' encoding='UTF-8'?> 
   <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"> 
      <soapenv:Header> 
         <wsa:To xmlns:wsa="http://www.w3.org/2005/08/addressing">http://localhost:8281/services/StockQuoteProxy</wsa:To> 
         <wsa:MessageID xmlns:wsa="http://www.w3.org/2005/08/addressing">urn:uuid:F6BE3F51CABFB86C131305006461276</wsa:MessageID> 
         <wsa:Action xmlns:wsa="http://www.w3.org/2005/08/addressing">http://schemas.xmlsoap.org/ws/2005/02/rm/CreateSequence</wsa:Action> 
      </soapenv:Header> 
      <soapenv:Body> 
         <wsrm:CreateSequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"> 
            <wsrm:AcksTo> 
               <wsa:Address xmlns:wsa="http://www.w3.org/2005/08/addressing">http://www.w3.org/2005/08/addressing/anonymous</wsa:Address> 
            </wsrm:AcksTo> 
            <wsrm:Offer> 
               <wsrm:Identifier>urn:uuid:C9C5EC706B1630B02F70948019826771537414401</wsrm:Identifier> 
            </wsrm:Offer> 
         </wsrm:CreateSequence> 
      </soapenv:Body> 
   </soapenv:Envelope> 

Once the WS-RM enabled server receive this request he responds with a create sequence response which looks like below.

<?xml version='1.0' encoding='UTF-8'?> 
   <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"> 
      <soapenv:Header xmlns:wsa="http://www.w3.org/2005/08/addressing"> 
         <wsa:MessageID>urn:uuid:8FBBE3295CC69847831305006465945</wsa:MessageID> 
         <wsa:Action>http://schemas.xmlsoap.org/ws/2005/02/rm/CreateSequenceResponse</wsa:Action> 
         <wsa:RelatesTo>urn:uuid:F6BE3F51CABFB86C131305006461276</wsa:RelatesTo> 
      </soapenv:Header> 
      <soapenv:Body> 
         <wsrm:CreateSequenceResponse xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"> 
            <wsrm:Identifier>urn:uuid:8FBBE3295CC69847831305006465893</wsrm:Identifier> 
            <wsrm:Accept> 
               <wsrm:AcksTo> 
                  <wsa:Address xmlns:wsa="http://www.w3.org/2005/08/addressing">http://localhost:8281/services/StockQuoteProxy</wsa:Address> 
               </wsrm:AcksTo> 
            </wsrm:Accept> 
         </wsrm:CreateSequenceResponse> 
      </soapenv:Body> 
   </soapenv:Envelope>

Once the sequence is established, client sends the request to the server with the pre-negotiated sequence ID.

<?xml version='1.0' encoding='UTF-8'?> 
   <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"> 
      <soapenv:Header> 
         <wsa:To xmlns:wsa="http://www.w3.org/2005/08/addressing">http://localhost:8281/services/StockQuoteProxy</wsa:To> 
         <wsa:FaultTo xmlns:wsa="http://www.w3.org/2005/08/addressing"> 
            <wsa:Address>http://www.w3.org/2005/08/addressing/anonymous</wsa:Address> 
         </wsa:FaultTo> 
         <wsa:MessageID xmlns:wsa="http://www.w3.org/2005/08/addressing">urn:uuid:F6BE3F51CABFB86C131305006461045</wsa:MessageID> 
         <wsa:Action xmlns:wsa="http://www.w3.org/2005/08/addressing">urn:getQuote</wsa:Action> 
         <wsrm:Sequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm" soapenv:mustUnderstand="1"> 
            <wsrm:Identifier>urn:uuid:8FBBE3295CC69847831305006465893</wsrm:Identifier> 
            <wsrm:MessageNumber>1</wsrm:MessageNumber> 
            <wsrm:LastMessage /> 
         </wsrm:Sequence> 
      </soapenv:Header> 
      <soapenv:Body> 
         <m0:getQuote xmlns:m0="http://services.samples"> 
            <m0:request> 
               <m0:symbol>IBM</m0:symbol> 
            </m0:request> 
         </m0:getQuote> 
      </soapenv:Body> 
   </soapenv:Envelope> 

Client keeps on sending above message till the server responds with a valid response message with 200 OK HTTP header. If the server is not ready with a response, it will respond with 202 Accepted HTTP header for all requests. Once the server is ready with a response it will send the response message with sequence ID as follows.

HTTP/1.1 200 OK 
Content-Type: text/xml; charset=UTF-8 
Date: Tue, 10 May 2011 05:47:48 GMT 
Transfer-Encoding: chunked 

85a 
<?xml version='1.0' encoding='UTF-8'?> 
   <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"> 
      <soapenv:Header> 
         <wsa:FaultTo xmlns:wsa="http://www.w3.org/2005/08/addressing"> 
            <wsa:Address>http://www.w3.org/2005/08/addressing/anonymous</wsa:Address> 
         </wsa:FaultTo> 
         <wsa:MessageID xmlns:wsa="http://www.w3.org/2005/08/addressing">urn:uuid:CD6DD195597E970CCC7102452795842-1496332077</wsa:MessageID> 
         <wsa:Action xmlns:wsa="http://www.w3.org/2005/08/addressing">//services.samples/SimpleStockQuoteServicePortType/getQuoteResponse</wsa:Action> 
         <wsa:RelatesTo xmlns:wsa="http://www.w3.org/2005/08/addressing">urn:uuid:F6BE3F51CABFB86C131305006461045</wsa:RelatesTo> 
         <wsrm:Sequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm" soapenv:mustUnderstand="1"> 
            <wsrm:Identifier>urn:uuid:C9C5EC706B1630B02F70948019826771537414401</wsrm:Identifier> 
            <wsrm:MessageNumber>1</wsrm:MessageNumber> 
            <wsrm:LastMessage /> 
         </wsrm:Sequence> 
         <wsrm:SequenceAcknowledgement xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm" soapenv:mustUnderstand="0"> 
            <wsrm:Identifier>urn:uuid:8FBBE3295CC69847831305006465893</wsrm:Identifier> 
            <wsrm:AcknowledgementRange Lower="1" Upper="1" /> 
         </wsrm:SequenceAcknowledgement> 
      </soapenv:Header> 
      <soapenv:Body> 
         <ns:getQuoteResponse xmlns:ns="http://services.samples"> 
            <ns:return xmlns:ax21="http://services.samples/xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="ax21:GetQuoteResponse"> 
               <ax21:change>-2.6700218511136207</ax21:change> 
               <ax21:earnings>-8.794748965262057</ax21:earnings> 
               <ax21:high>-187.17305566079403</ax21:high> 
               <ax21:last>187.8527959982049</ax21:last> 
               <ax21:lastTradeTimestamp>Tue May 10 11:17:47 IST 2011</ax21:lastTradeTimestamp> 
               <ax21:low>194.26444313628625</ax21:low> 
               <ax21:marketCap>4.0781086886418656E7</ax21:marketCap> 
               <ax21:name>IBM Company</ax21:name> 
               <ax21:open>196.0840596773702</ax21:open> 
               <ax21:peRatio>-17.81582827663666</ax21:peRatio> 
               <ax21:percentageChange>1.4459782819162954</ax21:percentageChange> 
               <ax21:prevClose>-184.65158740663455</ax21:prevClose> 
               <ax21:symbol>IBM</ax21:symbol> 
               <ax21:volume>18332</ax21:volume> 
            </ns:return> 
         </ns:getQuoteResponse> 
      </soapenv:Body> 
   </soapenv:Envelope>

Note the http status code.

Now both client and the server are done with the actual message exchange. Then client sends a request(terminate sequence) to terminate the sequence as follows:

<?xml version='1.0' encoding='UTF-8'?> 
   <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"> 
      <soapenv:Header> 
         <wsa:To xmlns:wsa="http://www.w3.org/2005/08/addressing">http://localhost:8281/services/StockQuoteProxy</wsa:To> 
         <wsa:MessageID xmlns:wsa="http://www.w3.org/2005/08/addressing">urn:uuid:F6BE3F51CABFB86C131305006468790</wsa:MessageID> 
         <wsa:Action xmlns:wsa="http://www.w3.org/2005/08/addressing">http://schemas.xmlsoap.org/ws/2005/02/rm/TerminateSequence</wsa:Action> 
         <wsrm:SequenceAcknowledgement xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm" soapenv:mustUnderstand="0"> 
            <wsrm:Identifier>urn:uuid:C9C5EC706B1630B02F70948019826771537414401</wsrm:Identifier> 
            <wsrm:AcknowledgementRange Lower="1" Upper="1" /> 
         </wsrm:SequenceAcknowledgement> 
      </soapenv:Header> 
      <soapenv:Body> 
         <wsrm:TerminateSequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"> 
            <wsrm:Identifier>urn:uuid:8FBBE3295CC69847831305006465893</wsrm:Identifier> 
         </wsrm:TerminateSequence> 
      </soapenv:Body> 
   </soapenv:Envelope> 

Server responds to the sequence termination message, accepting to terminate the sequence as follows.

<?xml version='1.0' encoding='UTF-8'?> 
   <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"> 
      <soapenv:Header xmlns:wsa="http://www.w3.org/2005/08/addressing"> 
         <wsa:ReplyTo> 
            <wsa:Address>http://localhost:8281/services/StockQuoteProxy</wsa:Address> 
         </wsa:ReplyTo> 
         <wsa:MessageID>urn:uuid:8FBBE3295CC69847831305006472014</wsa:MessageID> 
         <wsa:Action>http://schemas.xmlsoap.org/ws/2005/02/rm/TerminateSequence</wsa:Action> 
      </soapenv:Header> 
      <soapenv:Body> 
         <wsrm:TerminateSequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"> 
            <wsrm:Identifier>urn:uuid:C9C5EC706B1630B02F70948019826771537414401</wsrm:Identifier> 
         </wsrm:TerminateSequence> 
      </soapenv:Body> 
   </soapenv:Envelope>

Note that although each of above messages are separate SOAP messages, in most cases they will be exchanged in a single socket connection as HTTP Keep-Alive header is used. As you have observed these messages go between the client and the server ( and when you monitor you should see three pair of request/response).

Unlike in WS-Security case when you enable WS-RM for a web service you can't see any WS-RM specific information on the service's WSDL. When you generate clients against a WS-RM enabled service you'll have to enable the required parameters at the client code.