Getting started with NServiceBus, Request-Response example

In this blog post we explain some request-response example that we mentioned in the previous blogpost.

Below you can see the first steps to do, before we really can start with sending some messages.

  - Go to http://www.nservicebus.com à Downloads
  - Download the msi file under the “Get version 3.3.1 now” button.

 

   - Install the msi file on your system.
   -  Now you can find under “All programs > NServicebus v3.3.1” a Welcome to NServiceBus link.

You can click on the samples link to go to the samples. Or you can choose a sample below. We will talk about the “FullDuplex – RequestResponse” sample. Copy past the location of the sample and open it with visual studio. You will get the following solution.

The client is going to send a message to the server, the server will process the message and return it back to the client.

Let’s run the server and client application. You should see some screens like below.

Now we can exchange some messages between server and client. Let’s hit the “Enter” button in the Client Console. The client sends a message to the server with a Guid, which is received by the server and the server sends a message back to the client.

As you can see, this is not a real life scenario. What if the client is down? What if the server is down.

Let’s now start only the client application.

As you can see we send a message from the client to the server, but we don’t get some reaction back from the server because we didn’t start the server application. You don’t lose the message because NServicebus uses MSMQ and the message stays in the queue.

When we look in the MSMQ queue, you can see that there is a message.

Now we open the message, there you can find the DataID in the message. This ID is the same as on the Client application.

Now we can start the server application.

You can now see that the server picks up the message to process it. And send it back to the client.

I hope you enjoyed reading this blogpost.

Author: Sven Van den brande

What is NServiceBus

NServicebus is designed for collaboration between different services. It’s not just a replacement for WCF, BizTalk, ….. You can easily combine NServiceBus with BizTalk.

For BizTalk, the communication goes through one central box. We can call BizTalk a Broker style. All the information goes through BizTalk itself.

NServiceBus is something different. It’s more a peer-to-peer architecture that works on the message queues from Microsoft ( MSMQ ). So NServiceBus will do all the communication between systems with MSMQ. When you handle your message you still need to do the further communication.

When one of the “servers” go down because some hardware failure,... the communication between the other systems continues. This is some key feature for NServiceBus because you can keep sending messages. When the systems comes back online after the repair. It will get all the messages from the other systems, because they hold their  messages in the queues .

                                       

Now you know the basic difference between some other Integration tools. Like always a demo/example says more than thousands words.  So in the next blog post we will setup, the NServiceBus Environment and let you see some simple example about Request / Response.

Do you want to read more about NServiceBus, stay tuned!

Author: Sven Van den brande

Getting a glimpse of the Webmethods Integration Server OSGi-container.

After having followed an excellent presentation @Devoxx (Modular Architecture Today by Kirk Knoernschild), I decided to dive a bit into the OSGi container of SoftwareAG's Integration Server.

As documentation on this is scarce, the following information is not official and just bits and pieces I picked up, or investigated myself. The OSGi container was introduced in version 8.2.2, to cope with new components such as the Event server.

What SAG decided to do with the OSGi runtime, was to run the IS as one bundle and other components (such as the event server or common components) as other bundles. As runtime they choose the equinox implementation from Eclipse. This implementation comes with an easy to use console which can show us all the (active/loaded) bundles. This will be the goal of this article to get the console running and show us the bundles SAG is loading.

We're in luck: all we need to do is add "-console [port]" to the start-up of the OSGi-container. If you think you can find it in server.bat, you're half way there...this file now points to the OSGi-container, which you can find under [your_install_dir]\profiles\IS. We are interested in the start-up, so we will open "bin\runtime.bat". There you will find:

%JAVA_RUN% -Xbootclasspath/a:"%OSGI_CLASSPATH%" %JAVA_OPTS% %JAVA_SYSPROPS% -cp "%OSGI_FRAMEWORK_JAR%" org.eclipse.equinox.launcher.Main -configuration %OSGI_CONFIGURATION_AREA% %CMD_ARGS%

Just change it to:

%JAVA_RUN% -Xbootclasspath/a:"%OSGI_CLASSPATH%" %JAVA_OPTS% %JAVA_SYSPROPS% -cp "%OSGI_FRAMEWORK_JAR%" org.eclipse.equinox.launcher.Main -configuration %OSGI_CONFIGURATION_AREA% %CMD_ARGS% -console [port]

with [port], the port which you want to use to access the console.

Now just launch the server.bat. In your prompt, you should see something like: "Listening on port [port] ...". So lets now connect to the console, just open a telnet session to the port and your there:

telnet localhost [port]

Next type "ss" and you should get a list of all the bundles that are loaded:

Some useful commands are listed below:

start	Starts a bundle given an ID or symbolic name
stop	Stops a bundle given an ID or symbolic name
install	Adds a bundle given a URL for the current instance
uninstall	Removes a bundle given a URL for the current instance
update	Updates a bundle given a URL for the current instance
active	Lists all active bundles in the current instance
headers	List the headers for a bundle given an ID or symbolic name
ss	Lists a short status of all the bundles registered in the current instance
services <filter>	Lists services given the proper filter
diag	Runs diagnostics on a bundle given an ID or symbolic name

Hopefully this could prove helpful, especially when SAG extends its use of OSGi.

Author: Stefan

SAP NetWeaver Cloud Integration

During the TechEd conference, SAP has released more information about their new Netweaver Cloud Integration offering, that is the "Integration-As-As-Service" offering from SAP.

From this presentation we learn that Netweaver Cloud Integration is not "SAP PI in the cloud", but comes very close to it.  Netweaver Cloud Integration is fully compatible and integrated with the on-premise version of SAP PI. Same development, configuration and monitoring approach.

Also interesting is the blog entry of Prasanna Burri where he talks about using Netweaver Cloud Integration with SuccessFactors.  In his answers to questions, Prasanna mentions an availability date of Feb. 2013.

Author: Guy

IBM DataPower as ESX appliance

i8c does quite some work with IBM WebSphere DataPower.  And counts a number of experienced and certified DataPower developers and architects.  DataPower is great at securing and mediating web services.

Colleague Kim came up with a very interesting evolution: DataPower as a virtual appliance, so the XG45 gateway and XI52 integration appliance as ESX images.

This is similar to the CastIron offering of IBM that comes with on-premise hardware and virtual appliances.  Right now we have a CastIron instance running on our ESX server (i8c employees can deploy their images either on an ESX server or a Windows server running HyperV).

Note: together with Joris Verberckmoes (Lead Designer SOA Services @ Gdf-Suez) I'll be giving a presentation at the Belgian WebSphere User Group on Nov 27; topic is the use of DataPower @ Gdf-Suez

Author: Guy

Web Service incompatibilities

SOAP Web Services have lost quite some of their popularity: too complex, incompatibilities etc.  My answer is always that 1) SOAP just adds a very simple envelope around the request and response messages and 2) SOAP does work fine when you stick to the rules (a copy of a slide I use in my training classes):

Just recently I had encountered 2 nice examples of SOAP incompatibilities.
 

Cookies and SOAP

While investigating the web services API of a cloud SAAS application, encountered another example how things should not be done.  First of all it was not "stateless" but required the use of a login and logout operation. With security not based on standard HTTP basic authentication or WS-Security, but a proprietary scheme:

  <urn:credential>

    <urn:companyId>company-id</urn:companyId>

    <urn:username>user-name</urn:username>

    <urn:password>password</urn:password>

  </urn:credential>

But then came the surprise: the login operation returns a session handle which is actually a cookie! The cookie is to be passed as an HTTP header in each subsequent web service.  Had seen many ways to make web service implementations incompatible, but this is one for the top 5!  Obviously most web service clients require some hack to pass this cookie along the SOAP request.
 

Doc/literal with 2 parts

A more subtle challenge came recently by at a customer: the IBM DataPower ESB refused to import the WSDL file an Oracle product.  The web service used the document/literal style and one of the operations had a request message consisting of 2 parts.  So who was wrong and who was right: IBM or Oracle?

SOAP went through some growing pains in the beginning. The initial idea was an RPC mechanism whereby an operation could have multiple parameters. These parameters are passed as multiple parts in a request and response message. But with a better understanding of XML and XML schema's, the world move to a model whereby XML documents were passed. Microsoft introduced the document/literal wrapped style whereby the root contains the name of the operation.

<soap:Envelope xmlns:soap="http://www.w3.org/2001/12/soap-envelope">

  <soap:Body>

    <OperationName>

      actual XML document...

    </operationName>

  <soap:Body>

</soap:Envelope

</soap:Envelope>

So my initial response was, document/literal web services should only have one part and Oracle is wrong. But a colleague pointed to the fact that Oracle would not implement web services that violate the standards. And indeed, the IBM article clearly explains that a document/literal web service can have multiple parts in a message.

The WS-I Basic Profile was an initiative to sharpen the rules and states: "R2201 A document-literal binding in a DESCRIPTION MUST, in each of its soapbind:body element(s), have at most one part listed in the parts attribute, if the parts attribute is specified.". So the Oracle web service is not WS-I basic compliant but does not violate the SOAP/WSDL specifications.

Again a situation where one has to go for workaround, this time in the DataPower ESB. Had IBM implemented the specs correctly and/or Oracle stuck to the widely accepted ways-of-working and the WS-I Basic profile, everything would have worked smoothly.

 

Author: Guy

Live from Software AG Processworld 2012: Day 2

On day 2 of ProcessWorld I attended some sessions that were focusing on the 9.0 release. The first one was about a general introduction to webMethods 9.0. It started with a short overview of the new products: webMethods cloudStreams, webMethods Pulse, Command Central, ActiveTransfer, etc. After that they dived into the new functions of the existing components like IntegrationServer, Broker, Optimize, etc. The most important ones are:

For integration server:

• Support for webservice reliable messaging, SFTP and JSON. 
• Worry-free updates with maintenance mode support. You can put the integration server in maintenance mode to perform updates. 
• Local development. 
• BigXML and service caching thanks to the implementation of TerraCotta. 
• WebMethods Command Central Integration. 

For Trading Networks: 

• Community management & partner on-boarding 
• Integration of the new webMethods ActiveTransfer product. 

For BPM: 

• Improved architecture by OSGI enablement of the my webMethods Server. 
• Event-enabled BPM processes can feed webMethods Pulse, Business Events & Mashzone. 
• BPMN 2.0 support for sub-processes & debugging 

Optimize:

• Improved usability & management of KPI data. 
• Enhanced dashboards with MashZone. 
• Improved reliability. 
• WebMethods Command Central Integration 

CentraSite: 

• New business UI for occasional & non-technical users 
• Easy keyword search 
• Event-based automatic promotion across life-cycle states 
• Simplified infrastructure 
• WebMethods Command Central Integration 

Nirvana messaging: 
Something I forgot to mention in my previous blog post is that Nirvana also supports priority messaging and message throttling for bandwidth limitations.
 

Important to mention are the following system requirements for the whole webMethods 9.0 suite.

• There will be ipV6 support 
• Only 64-bit operating systems will be supported 
• The standard JDK is Java 7 
• The ability to define checkpoints & the rollback of deployments  

Another new webMethods product that I didn’t mention yesterday is webMethods ActiveTransfer for Managed File Transfer. There are two major components: ActiveTransfer server & ActiveTransfer proxy. The ActiveTransfer server needs to be installed on an IntegrationServer in the trusted zone of your IT infrastructure. The server part allows you to:

• Configure and manage all server instances centrally. It allows you to define IP banning rules and/or filename or folder restrictions. 
• Manage users and their access privileges by prioritizing file transfers, restrict file transfer actions and inheritance of user settings from templates. 
• Perform post-processing and alerting by the definition of file transfer criteria based triggers. Based on these triggers IntegrationServer services can be invoked or native scripts can be called. 
• Perform scheduled and event-driven transfers 
• Accelerate file transfers in high latency environments by definition of multiple active transfer tunnels. This allows file transfers speed up to 20 times faster. 
• Suspend and resume file transfers by the definition of checkpoints 
• Provide centralized monitoring to keep track of all transfers.

 

The ActiveTransfer proxy server part runs on a reverse gateway IntegrationServer in the DMZ and communicates with third parties.

Author: Dimitri Van Kerckhoven