Can anyone tell me what all can be the endpoints on an Websphere ESB. Like a web service, bpel process etc. what else can be there.!?
Thanks in advance!
Before I attempt to answer your question, I would like to bring something important to your attention
WebSphere ESB product has been sun-set. The product features have been merged into IIB (earlier called as WebSphere Message Broker).
If you are starting now, I would suggest that you explore IIB instead of WESB.
WESB can expose services via multiple means - WebServices (SOAP/HTTP and JMS) and messages (via both JMS or MQ).
In WESB terms we call them as exports. Exports are the ways by which a service is exposed to the external world.
Note: BPEL processes cannot be hosted in a WESB environment.
Related
We are designing a solution that will consume messages from IBM MQ using JMS. The plan is to use WAS Liberty, so JMS is the technology of choice. We will create Message-Drive beans that will listen for messages in MQ queues.
We are considering both WAS Liberty and OpenLiberty as well.
The trick here is that we must implement it with fail-over, so that if one of our server fail, the other will keep consuming messages from MQ automatically. Like in a ative/passive mechanism.
I'm aware that the MQ adapter needs to be installed as it is not provided out-of-the-box.
I have the following questions:
Does WAS Liberty messaging implementation supports fail-over? Meaning that if the ative message consumer node fails, the stand-by node will automatically migrate and start consuming messages from MQ? What about OpenLiberty?
How can I configure the message system to work that way? Can you point out to the documentation?
Or is this feature only provided by WebSphere?
There is no such functionality in WebSphere Liberty or Open Liberty yet. You can create RFE here https://www.ibm.com/developerworks/rfe/?PROD_ID=544 .
There are ways to do it manually, check these links:
JMS Activation spec on Liberty: “WAS_EndpointInitialState” full profile equivalent property?
Controlling the state of endpoints at runtime
Solution that you could do:
create a script/application that will monitor your servers and call that API to enable/disable endpoint in specific server
or use Dynamic cluster/ auto scaling feature of Liberty and divide you app to two clusters - one with MDBs, one without. And then define policy that MDBs cluster has 1 instance always available. So once the server dies it is automatically restarted somewhere in the cluster
or use Kubernetes/ICP platform in the same way - so deploying 2 versions of app, and defining different replicasets parameters.
I want to know the major difference between VM and JMS component of Mule ESB. Can someone help me to know it.
As per Mule documentation, VM transport is for intra-JVM communication between Mule flows. So, that means when you use a VM in your flow, you can communicate between different flows in the application.
A flow containing VM inbound cannot be called externally from external application as thus the flow is equivalent to a private flow used within the application. By default uses in-memory queues.
Please go through the documentation :- https://docs.mulesoft.com/mule-user-guide/v/3.8/vm-transport-reference
On the other hand as per Mule documentation, JMS is an external host, allows communication between different components of a distributed application and JMS transport lets you easily send and receive messages to queues and topics for any message service which implements the JMS specification.
A flow, which has JMS inbound can be called from externally unlike VM. Documentation is here :- https://docs.mulesoft.com/mule-user-guide/v/3.8/jms-transport-reference
Within the application, if you send the control from one flow to another flow we use VM.VM can be used as both inbound and outbound.
Outside the application, for example, A application want to send something to B application(external application) there we use JMS.
I have few basic douts.
I have developed a JMS application for P-P and the messages are geeting stored in Jboss 7.1 JMS engine. My questions are below.
1.For any JMS application do we need to have any messaging engine like IBM MQ,HornetQ,Active MQ etc
If Yes then we need to configure the MQ to atlk to Appserver Messaging engine.
3.If No, Then we need to have to create a message consumer
JMS is a specification of a messaging interface - and a state model for how messages are handled in transactions.
jms.jar contains pretty much all interfaces - no implementations. Therefore whilst you can write an application against jms.jar you can't actually run it.
You'll need to pick some type of messaging provider. That's appropriate to your requirements.
That's not a discussion for here however keep in mind that they each have possible extensions and functional behavior outside of the specification so if you want to be portable between providers pay close attention to only use specification defined functionality.
Within a JavaEE Application Server there will be a JMS implementation that provides messaging features. Therefore an app here in JBOSS will be a MOM (messaging oridentated middleware) application. If you want the message to be accessed by an application not running in a JavaEE server then that is possible with some providers. There's often a JavaEE client container. Or the messaging engine will have a JavaSE based client that can be used. (WAS thin client client for example).
Remember that with JavaEE servers you are not restricted to a the choice of messaging provider - you can use the JCA interface to directly plug in a external messagin implementation. This might present an easier route if a lot of messaging will be outside the JavaEE server.
EDIT - added JavaEE notes
I am not expert in JMS and recently came across a situation in my project where they wanted to use JMS to communicate between applications. Is it possible to make use of JMS without an underlying MQ software like Websphere MQ / TIBCO EMS to communicate asynchronously. My thinking is that just like we use JDBC API to speak to a physical Database product (like Oracle/DB2 DB) underneath, we would use JMS to speak to a physical queue. But my team says just JMS and no queue. Can anyone help me understand? We use Websphere 6.0 server and use spring framework.
Thanks in advance.
You are correct: JMS is solely an interface, it contains no implementation. The comparison with JDBC is quite fitting.
When using JMS you always need a JMS provider. A provider is the JMS implementation, which interfaces a message oriented middleware.
Most application servers have built in JMS providers, so maybe your team meant using JMS without an external provider.
Is it possible to make use of JMS without an underlying MQ software like Websphere MQ / TIBCO EMS to communicate asynchronously
This makes no sense. Few points to note -
JMS is just specs. By specs you can imagine it as set of APIs/interfaces/ method signatures and governing rules.
There are various organization/companies that provide implementation of these APIs.Apache's ActiveMQ,IBM's Websphere MQ or TIBCO EMS are some of the examples.
Now when you say I want to use JMS then you need a JMS compatible server i.e server which understands the rules laid down by specs. This is generally know as MQ server and is provided by the provider.
My thinking is that just like we use JDBC API to speak to a physical Database product (like Oracle/DB2 DB) underneath, we would use JMS to speak to a physical queue. But my team says just JMS and no queue
Two things to note here. When you say you want to use databases and JDBC APIs to communicate JMS comes no where in the picture. Please understand why JMS is used. In short it is used to transfer messages between two decoupled system. What storage type JMS server uses(and if it is configurable) will depend on the provider. Generally all have DB storage type and can be configured to use your DB.
Next JMS has two types of communications - PTP(peer to peer) which uses queues and PUBSUB(publish subscribe) which uses Topics. When you say you are using JMS everything boils down to either of these two and some of it's variants.Now when you say JMS without a queue perhaps your team meant using PUBSUB. But again it is not something you decide randomly and use it in your application. This decision is takes as per what your requirement is as both of them behave differently.
First you will need queues/topics to use JMS.
Second (your team probably means not using WebSphere MQ because my team was saying the same thing)
This diagram in IBM's Red Book will fully answer your question (it is the same as WS6):
http://www.redbooks.ibm.com/redbooks/pdfs/sg247770.pdf
page 4.
Probably what you will be using is the WebSphere Default Messaging Provider.
I have a application in which I need to route my JMS messages to different managed servers based on some selector value. But I cannot use JMS bridges for the purpose as the application has more than 20 managed servers in production.so with the JMS bridge approach, it will become a hurdle for the deployment team to do such huge configuration.
Maybe You could try to use the Mule ESB or other ESB approach. I recommend the Mule ESB because it's simple, well documented and pretty lightweight.