Aggregation Nodes WMB

WebService scenario in WMB V7.0

This post elaborates a particulate scenario where Aggregation is being implemented using different web service nodes ( SOAP & HTTP Nodes)

Background :
Aggregation is the generation and fan-out of related requests that are derived from a single input message. It is also the fan-in of the corresponding replies to produce a single aggregated reply message.

Aggregation is an advanced form of message routing. With aggregation, a request message is received, and multiple new different request messages are generated. Each new message is routed to its  destination using a request-reply interaction.

Aggregation Nodes:

• AggregateControl, AggregateRequest nodes (Used in Fan-Out to broadcast the request message to multiple destinations 
• AggregateReply (Used in Fan-In to collect responses)
• ‘Aggregate Name’ property of AggregateControl & AggregateReply nodes should be the same.
• ‘Folder Name’ property of the AggregateRequest node decide how the input will be structured  in Fan-Out flow.
• The AggregateReply node creates a folder in the combined message tree below Root, called ComIbmAggregateReplyBody. Below this folder, the node creates a number of subfolders using the names that you set in the AggregateRequest nodes. These subfolders are populated with the associated reply messages.

Broker internally maintains aggregation state in following queues:

• SYSTEM.BROKER.AGGR.REQUEST
• SYSTEM.BROKER.AGGR.CONTROL
• SYSTEM.BROKER.AGGR.REPLY
• SYSTEM.BROKER.AGGR.UNKNOWN
• SYSTEM.BROKER.AGGR.TIMEOUT

Core Aggregation Flows :

Fan Out Flow :

Fan In Flow :

Input :

      <myms:SaleEnvelope  xmlns:myms="http://tempuri.org/MyMS">
         <myms:SaleList>
            <myms:Invoice>
               <myms:Initial>A</myms:Initial>
               <myms:Balance>B</myms:Balance>
               <myms:Currency>C</myms:Currency>
            </myms:Invoice>
         </myms:SaleList>
       <myms:SaleList>
            <myms:Invoice>
               <myms:Initial>A1</myms:Initial>
               <myms:Balance>B1</myms:Balance>
               <myms:Currency>C1</myms:Currency>
            </myms:Invoice>
         </myms:SaleList>
      </myms:SaleEnvelope>

Output :
<ABC>
 <AG2>
  <SaleEnvelope>
   <SaleList>
    <Invoice xmlns:NS1="http://tempuri.org/MyMS">
     <Initial>a</Initial>
     <Balance>60.16</Balance>
     <Currency>Dollar</Currency>
    </Invoice>
   </SaleList>
  </SaleEnvelope>
 </AG2>
 <AG1>
  <SaleEnvelope>
   <SaleList>
    <Invoice xmlns:NS1="http://tempuri.org/MyMS">
     <Initial>S</Initial>
     <Balance>07.55</Balance>
     <Currency>Rupees</Currency>
    </Invoice>
   </SaleList>
  </SaleEnvelope>
 </AG1>
</ABC>

Wrapper (Web Service) Flows :

The same flow can be called by HTTPInput Node or SOAPInput Node.

HTTPCaller Flow :

Input & Output for the above flow would be same as normal flow mentioned above.

Different ways of calling HTTPInput node (Web Service implemented using HTTP nodes) :

• nettool (Its a tool ; Need to give the URL & input xml)
• Another message flow which uses HTTPRequest node to call HTTPCaller flow.
• Java : Can be called through plain Java code; following code sample is a standalone Java program to call HTTPCaller flow.

Code :

import java.io.BufferedReader;

import java.io.DataOutputStream;

import java.io.FileReader;

import java.io.InputStreamReader;

import java.net.URL;

import java.net.URLConnection;

public class HTTPCaller{

public static void main(String[] args) throws Exception {

// Default port for HTTPInput node is 7080

// Path suffix for URL :/path/to/aggrservice/

URL url = new URL("http://localhost:7080/path/to/aggrservice/");

URLConnection urlConn = url.openConnection();

FileReader fileReader = new FileReader("C://Input.xml"); // Input XML (It is same as above input xml)

urlConn.setDoOutput(true);

InputStreamReader inStream = null;

BufferedReader buff = null;

String nextLine;

String inputLine;

BufferedReader in = new BufferedReader(fileReader);

DataOutputStream printout = new DataOutputStream(urlConn.getOutputStream());

while ((inputLine = in.readLine()) != null){

printout.writeBytes(inputLine);

}

printout.flush();

printout.close();

// Get Response data.

inStream = new InputStreamReader(urlConn.getInputStream());

buff = new BufferedReader(inStream);

while (true) {

nextLine = buff.readLine();

if (nextLine != null) {

System.out.println(nextLine);

} else {

break;

}

}

in.close();

}

}

SOAPCaller Flow :

Input :
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:myms="http://tempuri.org/MyMS">
   <soapenv:Header/>
   <soapenv:Body>
      <myms:SaleEnvelope>
          <myms:SaleList>
            <myms:Invoice>
               <myms:Initial>A</myms:Initial>
               <myms:Balance>B</myms:Balance>
               <myms:Currency>C</myms:Currency>
            </myms:Invoice>
         </myms:SaleList>
         <myms:SaleList>
            <myms:Invoice>
               <myms:Initial>A1</myms:Initial>
               <myms:Balance>B1</myms:Balance>
               <myms:Currency>C1</myms:Currency>
            </myms:Invoice>
         </myms:SaleList>
      </myms:SaleEnvelope>
   </soapenv:Body>
</soapenv:Envelope>

Output :

<soapenv:Envelope xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

   <soapenv:Body>
      <ABC>
         <AG1>
            <SaleEnvelope>
               <SaleList>
                  <NS1:Invoice xmlns:NS1="http://tempuri.org/MyMS">
                     <NS1:Initial>A</NS1:Initial>
                     <NS1:Balance>B</NS1:Balance>
                     <NS1:Currency>C</NS1:Currency>
                  </NS1:Invoice>
               </SaleList>
            </SaleEnvelope>
         </AG1>
         <AG2>
            <SaleEnvelope>
               <SaleList>
                  <NS1:Invoice xmlns:NS1="http://tempuri.org/MyMS">
                     <NS1:Initial>A1</NS1:Initial>
                     <NS1:Balance>B1</NS1:Balance>
                     <NS1:Currency>C1</NS1:Currency>
                  </NS1:Invoice>
               </SaleList>
            </SaleEnvelope>
         </AG2>
      </ABC>
   </soapenv:Body>
</soapenv:Envelope>

Different ways of calling SOAPInput node (Web Service implemented using SOAP nodes) :

• SoapUI (Its a tool ; Need to give wsdl & input xml)
• Another message flow which uses SOAPRequest node to call SOAPCaller flow.
• Java : Can be called through plain Java code; following post has example of how to call a web service: http://harishonsoa.blogspot.com/2011/12/calling-any-service-using-webservice.html

// Default port for SOAPInput node is 7800

// Path suffix for URL : /MyMSSOAP_HTTP_Service ; so the URL would be http://localhost:7800/MyMSSOAP_HTTP_Service?wsdl