Importance of understanding your database

Recently I was working on an integration project where the database used was MS SQL server and the integration platform was Oracle SOA Suite.

The service itself was quite simple – to fetch some data from SQL server and Enqueue it on JMS queue. We used DB Adapter for polling the database. We used the Delete strategy and the service was distributed on a cluster.

Once the ids were enqueued, there was a seperate EJB-based webservice which queried same database to create the canonical. We have used JPA Entity Beans for ORM. There is a particular query to get some extra information from a table which does not have foreign-key relation. The query used a single parameter – a string.

However we observed a huge performance issue for SQL server as well as the website hosted on the database. We observed 99% CPU usage.

It was our SQL DBA who found out the issue. The column in database was varchar, the index was based on same. However, the query parameter that got sent to the database was using nvarchar. This caused a full table scan and completely skipped the index.

The solution use “sendStringParametersAsUnicode” property of Weblogic SQL Server driver. By default everything gets sent as Unicode from JDBC Driver, using “sendStringParametersAsUnicode=false”, we made the driver send the parameter as varchar and immediately saw the difference. CPU usage was down to 1%.

This underscores the point that Frameworks and Engines abstract out a lot of features, but it is necessary to understand you database to make optimal use of it.

Reference – http://msdn.microsoft.com/en-us/library/ms378988.aspx

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Generic Architecture for Cloud Apps Integration : Integrate multiple apps using JMS Publish – Subscribe

With the advent of cloud, the trend is to use cloud-based best of breed software for different needs. Although this provides very good and deep functionality, it also opens up a lot of issues related to data management and integrity.

A very common scenario nowadays is to use SaaS application like Salesforce or SugarCRM for CRM. Then to use SaaS ERP like NetSuite or on-premise ERP. There could also be Quickbooks used for accounting. Besides these there are the HelpDesk apps.

All of these applications have their own internal databases, schemas and representation of your data. A change in one place needs to be reflected in other apps as well. This results in lot of difficulties on how to integrate the apps. Conventional star topology or app-to-app integration fall short.

This is where a Messaging Oriented Middleware (MOM) solution like ESB is very useful. I am presenting a generic architecture for multiple apps to apps integration.

Brief explanation of components in the proposed architecure -

  • Purchase Order – This is the input document that comes to the system. We generally need to update multiple systems based on the docuemnt. The format could be cXML or any custom XML schema. It could be transformed into a standard or canonical format accepted internally.
  • ActiveMQ JMS – The document is put on Topic of any messaging application. I have assumed ActiveMQ here, but it could be any MQ system that supports publish-subscribe model.
  • Transformers – We have 3 subscribers to this Topic, however each of them accepts different formats. To compensate for this, we have a trasnfromer for each of the subscriber. e.g., the PO to CRM transformer could transform the message from CXML format to SalesForce.com Schema.
  • Subscribers – All 3 subscribers receive the message document and update their respective system with the data.
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Enterprise Integration Patterns (EIP) with OpenESB Part 2 : Dynamic Router

This is second of the series Enterprise Integration Patterns (EIP) with OpenESB where we will cover Enterprise Integration Patterns using OpenESB.


According to Enterprise Integration Patterns,

The Dynamic Router is a Router that can self-configure based on special configuration messages from participating destinations.

Dynamic Router

We can realize this pattern in OpenESB using Dynamic Addressing which uses WS-Addressing to dynamically determine the service location at runtime.

To check this in action we need 3 Projects -

  • EJB Module implementing the Web Service – you can use any WSDL based web service, not necessary to use EJB.
  • BPEL – This will contain the actual code that determines the endpoint at runtime.
  • JBI / CASA – This is a composite application necessary to deploy the BPEL.

Step 1 - We create a web service with 2 operations – addition and subtraction. Both operations take 2 numbers as input and return result.
Here’s the xsd –

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    targetNamespace="http://xml.aurorite.com/schema/numberBase"
    xmlns:tns="http://xml.aurorite.com/schema/numberBase"
    elementFormDefault="qualified">

    <xsd:element name="NumbersAdditionRequest" type="tns:AdditionType"/>
    <xsd:element name="NumbersAdditionResponse" type="tns:OperationResultType"/>
    <xsd:element name="NumbersSubtractionRequest" type="tns:SubtractionType"/>
    <xsd:element name="NumbersSubtractionResponse" type="tns:OperationResultType"/>

    <xsd:complexType name="AdditionType">
        <xsd:sequence>
            <xsd:element name="number1" type="xsd:int"/>
            <xsd:element name="number2" type="xsd:int"/>
        </xsd:sequence>
    </xsd:complexType>

    <xsd:complexType name="SubtractionType">
        <xsd:sequence>
            <xsd:element name="number1" type="xsd:int"/>
            <xsd:element name="number2" type="xsd:int"/>
        </xsd:sequence>
    </xsd:complexType>

    <xsd:complexType name="OperationResultType">
        <xsd:sequence>
            <xsd:element name="result" type="xsd:int"/>
            <xsd:element name="processor" type="xsd:string"/>
        </xsd:sequence>
    </xsd:complexType>
</xsd:schema>

and here’s the wsdl -

<?xml version="1.0" encoding="UTF-8"?>
<definitions name="NumbersOperations"
    targetNamespace="http://websvcs.aurorite.com/wsdl/NumberOperationSvcs/NumbersOperations"
    xmlns="http://schemas.xmlsoap.org/wsdl/"
    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
    xmlns:tns="http://websvcs.aurorite.com/wsdl/NumberOperationSvcs/NumbersOperations"
    xmlns:ns="http://xml.aurorite.com/schema/numberBase"
    xmlns:plnk="http://docs.oasis-open.org/wsbpel/2.0/plnktype"
    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/">
    <types>
        <xsd:schema targetNamespace="http://websvcs.aurorite.com/wsdl/NumberOperationSvcs/NumbersOperations">
            <xsd:import namespace="http://xml.aurorite.com/schema/numberBase" schemaLocation="numberBase.xsd"/>
        </xsd:schema>
    </types>
    <message name="additionRequest">
        <part name="part1" element="ns:NumbersAdditionRequest"/>
    </message>
    <message name="additionResponse">
        <part name="part1" element="ns:NumbersAdditionResponse"/>
    </message>
    <message name="subtractionRequest">
        <part name="part1" element="ns:NumbersSubtractionRequest"/>
    </message>
    <message name="subtractionResponse">
        <part name="part1" element="ns:NumbersSubtractionResponse"/>
    </message>
    <portType name="NumbersOperationsPortType">
        <operation name="addition">
            <input name="input1" message="tns:additionRequest"/>
            <output name="output1" message="tns:additionResponse"/>
        </operation>
        <operation name="subtraction">
            <input name="input2" message="tns:subtractionRequest"/>
            <output name="output2" message="tns:subtractionResponse"/>
        </operation>
    </portType>
    <binding name="NumbersOperationsBinding" type="tns:NumbersOperationsPortType">
        <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
        <operation name="addition">
            <soap:operation/>
            <input name="input1">
                <soap:body use="literal"/>
            </input>
            <output name="output1">
                <soap:body use="literal"/>
            </output>
        </operation>
        <operation name="subtraction">
            <soap:operation/>
            <input name="input2">
                <soap:body use="literal"/>
            </input>
            <output name="output2">
                <soap:body use="literal"/>
            </output>
        </operation>
    </binding>
    <service name="NumbersOperationsService">
        <port name="NumbersOperationsPort" binding="tns:NumbersOperationsBinding">
            <soap:address location="http://localhost:8080/NumbersOperationsService/NumberService"/>
        </port>
    </service>
    <plnk:partnerLinkType name="NumbersOperations">
        <!-- A partner link type is automatically generated when a new port type is added. Partner link types are used by BPEL processes. 
In a BPEL process, a partner link represents the interaction between the BPEL process and a partner service. Each partner link is associated with a partner link type.
A partner link type characterizes the conversational relationship between two services. The partner link type can have one or two roles.-->
        <plnk:role name="NumbersOperationsPortTypeRole" portType="tns:NumbersOperationsPortType"/>
    </plnk:partnerLinkType>
</definitions>

Here is the implementation of the webservice operations -

@WebService(serviceName = "NumbersOperationsService", portName = "NumbersOperationsPort", endpointInterface = "com.aurorite.websvcs.wsdl.numberoperationsvcs.numbersoperations.NumbersOperationsPortType", targetNamespace = "http://websvcs.aurorite.com/wsdl/NumberOperationSvcs/NumbersOperations", wsdlLocation = "META-INF/wsdl/NumberService/NumbersOperations.wsdl")
@Stateless
public class NumberService {

    Logger logger = Logger.getLogger("soa.aurorite.com.NumberService");

    public com.aurorite.xml.schema.numberbase.OperationResultType addition(com.aurorite.xml.schema.numberbase.AdditionType part1) throws UnknownHostException {
        logger.info("Running this service at " + InetAddress.getLocalHost().getHostName() + " on port 8080");
        com.aurorite.xml.schema.numberbase.OperationResultType result = new com.aurorite.xml.schema.numberbase.OperationResultType();
        result.setProcessor(InetAddress.getLocalHost().getHostName());
        try {
            result.setResult(part1.getNumber1() + part1.getNumber2());
        } catch (Exception e){
            result.setResult(0);
        }

        return result;
        //throw new UnsupportedOperationException("Not implemented yet.");
    }

    public com.aurorite.xml.schema.numberbase.OperationResultType subtraction(com.aurorite.xml.schema.numberbase.SubtractionType part1) throws UnknownHostException {
        logger.info("Running this service at " + InetAddress.getLocalHost().getHostName() + " on port 8080");
        com.aurorite.xml.schema.numberbase.OperationResultType result = new com.aurorite.xml.schema.numberbase.OperationResultType();
        result.setProcessor(InetAddress.getLocalHost().getHostName());
        try {
            result.setResult(part1.getNumber1() - part1.getNumber2());
        } catch (Exception e){
            result.setResult(0);
        }
        return result;
        //throw new UnsupportedOperationException("Not implemented yet.");
    }

}

Note that I’m returning the machine name in the response. This’ll help us to determine who actually processed a particular operation.

Now to the BPEL. We’ll create a simple process looking like this -
Dynamic Router BPEL

In the BPEL, we add these 2 namespace references -

xmlns:sref="http://docs.oasis-open.org/wsbpel/2.0/serviceref" 
xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing"
    <import namespace="http://docs.oasis-open.org/wsbpel/2.0/serviceref" location="ws-bpel_serviceref.xsd" importType="http://www.w3.org/2001/XMLSchema"/>
    <import namespace="http://schemas.xmlsoap.org/ws/2004/08/addressing" location="addressing.xsd" importType="http://www.w3.org/2001/XMLSchema"/>

And now the most important part – Adding the Service Endpoint Reference

<assign name="assign_endpoint">
    <copy>
                        <!--<from>ns2:doXslTransform('urn:stylesheets:wrap2serviceref.xsl', $EPRVariable.eprValue)</from>-->
        <from>
            <literal>
                <sref:service-ref>
                    <wsa:EndpointReference>
                        <wsa:Address>http://machine2:8080/NumbersOperationsService/NumberService</wsa:Address>
                        <wsa:ServiceName PortName="NumbersOperationsPort"
                                        xmlns:serv="http://websvcs.aurorite.com/wsdl/NumberOperationSvcs/NumbersOperations">serv:NumbersOperationsService
                        </wsa:ServiceName>
                    </wsa:EndpointReference>
                </sref:service-ref>
            </literal>
        </from>
        <to partnerLink="NumberService"/>
    </copy>
</assign>

The portname and Service name must match to the ones in target service.

Posted in BPEL, Integration, Java, SOA | 1 Comment

Enterprise Integration Patterns (EIP) with OpenESB Part 1 : Content-Based Router

This is first of the series Enterprise Integration Patterns with OpenESB where we will cover Enterprise Integration Patterns using OpenESB.


According to Enterprise Integration Patterns,

The Content-Based Router examines the message content and routes the message onto a different channel based on data contained in the message. The routing can be based on a number of criteria such as existence of fields, specific field values etc. When implementing a Content-Based Router, special caution should be taken to make the routing function easy to maintain as the router can become a point of frequent maintenance. In more sophisticated integration scenarios, the Content-Based Router can take on the form of a configurable rules engine that computes the destination channel based on a set of configurable rules.

Content Based Router

It can be achieved in OpenESB using “If” component.

In this example it simply checks for the value in “num:operation” element.

<soapenv:Envelope xsi:schemaLocation="http://schemas.xmlsoap.org/soap/envelope/ http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:num="http://xml.aurorite.com/schema/NumberOperationSchema">
  <soapenv:Body>
    <num:OperationRequest>
      <num:operation>ADDITION</num:operation>
      <num:data>
        <num:number1>20</num:number1>
        <num:number2>30</num:number2>
      </num:data>
    </num:OperationRequest>
  </soapenv:Body>
</soapenv:Envelope>     
Posted in BPEL, Integration, Java, SOA | 1 Comment

Can a SOA be designed with REST?

Recently I answered a question on stackoverflow.com asking can a SOA be designed with REST? I’m cross-posting the answer here.


 

At a high Level the answer is Yes, however not completely.

SOA requires thinking about the system in terms of

  • Services (well-defined business functionality)
  • Components (discrete pieces of code and/or data structures)
  • Processes (Service orchestrations. Generally using BPEL)

Being able to compose new higher level services or business processes is a basic feature of a good SOA. XML, SOAP based Web Services and related standards are good fit for realizing SOA.

Also SOA has a few accepted principles – http://en.wikipedia.org/wiki/Service-oriented_architecture#Principles

  • Standardized service contract – Services adhere to a communications agreement, as defined collectively by one or more service-description documents.
  • Service Loose Coupling – Services maintain a relationship that minimizes dependencies and only requires that they maintain an awareness of each other.
  • Service Abstraction – Beyond descriptions in the service contract, services hide logic from the outside world.
  • Service reusability – Logic is divided into services with the intention of promoting reuse.
  • Service autonomy – Services have control over the logic they encapsulate.
  • Service granularity – A design consideration to provide optimal scope and right granular level of the business functionality in a service operation.
  • Service statelessness – Services minimize resource consumption by deferring the management of state information when necessary.
  • Service discoverability – Services are supplemented with communicative meta data by which they can be effectively discovered and interpreted.
  • Service composability – Services are effective composition participants, regardless of the size and complexity of the composition.

A SOA based architecture is expected to have Service Definition. Since RESTful web services lack a definitive service definition (similar to wsdl), it is difficult for a REST based system to fulfill most of the above principles.

To achieve the same using REST, you’d need to have RESTful Web Services + Orchestration (possible using some lightweight ESB like MuleESB or Camel)

Please also see this resource – From SOA to REST


Adding this part as clarification for below comment -

Orchestration is required to compose processes. That’s what provides the main benefit of SOA.

Say you have a order processing application with operations like
-

  • addItem
  • addTax
  • calculateTotal
  • placeOrder

Initially you created a process (using BPEL) which uses these operations in sequence. You have clients who use this Composed Service. After a few months a new client comes who has tax exemption, then instead of writing new service, you could just create a new process skipping the addTax operation. Thus you could achieve faster realization of business functionality just by re-using existing service. In practice there are mutiple such services.

Thus BPEL or similar (ESB or routing) technology is essential for SOA. Without business use, a SOA is not really a SOA.

Posted in BPEL, Integration, REST, SOA, Uncategorized | Tagged , | Leave a comment

Enterprise Integration Patterns (EIP) with OpenESB

This is a series which’ll cover Enterprise Integration Patterns (EIP) using OpenESB.

Part 1:Enterprise Integration Patterns (EIP) with OpenESB Part 1 : Content-Based Router

Posted in Integration, Java, SOA | Tagged | 2 Comments

Siebel CRM On Demand Web Services – Contact Search using SoapUI

Before we begin using Siebel CRM On Demand’s web services, we require the WSDL files. The WSDL files are specific to the account and can be downloaded by logging in to Siebel COD.

Create a new SoapUI project and add the WSDL as initial WSDL. SoapUI will create a new project with placeholder requests for all operations. Let’s open ContactQueryPage operation from SoapUI.

The endpoint path will be something like – https://secure-ausoxxxxx.crmondemand.com/Services/Integration
This path is  unique to your instance of Siebel COD.

Next lets remove the body of input and replace it with -

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header/>
<soapenv:Body>
     <con:ContactQueryPage_Input xmlns:con="urn:crmondemand/ws/ecbs/contact/" xmlns:quer="urn:/crmondemand/xml/Contact/Query">
        <quer:ListOfContact startrownum="0" pagesize="100" recordcountneeded="true">
            <quer:Contact searchspec="[ContactFirstName] LIKE 'John'">
                <quer:Id/>
                <quer:ContactFirstName/>
                <quer:ContactLastName/>
                <quer:AccountId/>
            </quer:Contact>
        </quer:ListOfContact>
    </con:ContactQueryPage_Input>
</soapenv:Body>
</soapenv:Envelope>

This results in Soap Fault response with Siebel error code SBL-ODU-01006 and message : “Internal Error: Session is not available. Aborting.”
This is because we still haven’t added username/password for authentication. There is another option to first get the session and then pass that value in header of the request. However I prefer to use the Stateless version above, as it separates the responsibility of handling session.

Let’s make 2 changes to fix this error.
1) Replace first line of the SOAP request with -

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:wsse="http://schemas.xmlsoap.org/ws/2002/07/secext">

2) Add these lines just below the SOAP Envelope element -

<soapenv:Header>
   <wsse:Security>
      <wsse:UsernameToken>
         <wsse:Username>your_siebel_username</wsse:Username>
         <wsse:Password Type="wsse:PasswordText">your_siebel_password</wsse:Password>
      </wsse:UsernameToken>
   </wsse:Security>
</soapenv:Header>

What we’ve done here is added WS-SECURITY headers to the SOAP request.
Now the request should run just fine.

Note -
1) You need to add any fields you need to the request before they can be returned by Siebel CRM. e.g., <ContactFirstName/>
2) Its better to confirm data actually exists by logging through web-console.

Posted in Camel, Integration, Java, Siebel, SOA | Tagged , , , , | 10 Comments