I am trying to understand JMS.
What is the difference between ActiveMQ and JMS
can pool the data from NON ActiveMQ with ActiveMQ plugin in Spring?
Thanks ,In advance
JMS is a specification. JMS has three main parts to it. The first is the producer, which is nothing more than a bean that submits a "message" to a JMS broker (#2) (the system that manages messages between producers and consumers). In this case, ActiveMQ is the broker. Once the broker receives a message, the consumer (#3), or Message-Driven Bean (MDB), processes the message.
If you want to work with JMS, you'll just write both your producer/consumer code using the JMS API, but behind the scenes there is a "resource adapter" that is a special ActiveMQ driver that will connect to an ActiveMQ instance and do the management for you.
Have a look at this post I made recently. I'm still trying to figure out the best way to write JMS beans, but I've got the basics down.
The accepted answer emphasizes what is the structure of JMS is. Not disagreeing just want to add to it in case anyone else wants to know. ActiveMQ could be a JMS supplier. A JMS supplier shapes the computer program system for encouraging the utilize of JMS concepts interior an application. A single node of ActiveMQ which permits clients to associate to it and utilize these informing concepts is called an "ActiveMQ Broker."
Enterprises feel this disparity with business actions such as mergers and acquisitions. This creates the need to maintain an increasingly heterogeneous collection of business applications. As your enterprise grows, so does the need to allow all of these platforms to share data. A number of architectural patterns exist today which help to solve this problem.
Some other examples of JMS providers are:
HornetQ.
RabbitMQ.
SonicMQ.
Winsows Azure Messaging
The following example shows a simple configuration of an ActiveMQ connection:
<jms:config name="JMS_Config">
<jms:active-mq-connection >
<jms:factory-configuration brokerUrl="tcp://localhost:61616" />
</jms:active-mq-connection>
</jms:config>
This post explains a detailed difference between the ActiveMQ and JMS (or maybe about the details of their specifications). Hope it clears your concepts.
We are creating new application, which is going to use IBM's MQ as a JMS provider for a short term and switch to Tibco EMS within a year.
My question is how involving the changes would be from the Application code perspective.
So far reading from JMS documentation, my impression is it should only require minimal changes. Does anyone have experience with it and provide some input on the work involved in switching between JMS provider.
I've done POCs where I swapped out connection factories and used WMQ JMS Classes to send to various providers (TIBCO, ActiveMQ, etc), to prove out the interchangeability. I've also done full swaps from one vendors JMS to another. In theory, it should be very simple.
The biggest change will be with the connection factories. Everything JMS specific will be the same between providers. The more tightly coupled the code is to the connection factories, the more complex it will be to change the app itself. Outside of this, you may need to change vendor specific implementation of objects, such as MQQueue vs Queue.
One addition thing to keep in mid is dependent on the IBM endpoints. If you are using "target queue managers" on any producers, these will need to change. WMQ has a specific URI to reach queues on specific Queue Managers in a cluster ( "queue://target_qm/queue_name/" ). If any application uses this URI it will need to ensure it makes the proper changes here as well.
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
For me JMS and ESB seem to be very related things and I'm trying to understand how exactly they are related.
I've seen a sentence that JMS can be used as a transport for ESB - then what else except the transport should be present in such an ESB? Is JMS a simple ESB or if not, then what it lacks from the real ESB?
JMS offers a set of APIs for messaging: put a message on a queue, someone else, sometime later, perhaps geographically far away takes the message off the queue and processes it. We have decoupled in time and location of the message provider and consumer. Even if the message consumer happens to be down for a time we can keep producing messages.
JMS also offers a publish/subscribe capability where the producer puts the message to a "topic" and any interested parties can subscribe to that topic, receiving messages as and when they are produced, but for the moment focus just on the queue capabilty.
We have decoupled some aspects of the relationship between provider and consumer. However some coupling remains. First, as things stand every message is processed in the same way. Suppose we want to introduce different kinds of processing for different kinds of messages:
if ( message.customer.type == Platinum )
do something special
Obviously we can write code like that, but an alternative would be to have a messaging system that can send different messages to different places we set up three queues:
Request Queue, the producer(s) puts their requests here
Platinum Queue, platinum consumer processing reads from here
Standard Queue, a standard consumer reads messages from here
And then all we need is a little bit of cleverness in the queue system itself to transfer then messsage from the Request Queue to the Platinum Queue or Standard Queue.
So this is a Content-Based Routing capability, and is something that an ESB provides. Note that the ESB uses the fundamental Queueing capabilities offered by JMS.
A second kind of couppling is that the consumer and producer must agree about the message format. In simple cases that's fine. But when you start to have many producers all putting message to the same queue you start to hit versioning problems. New message formats are introduced but you don't want to change all the existing providers.
Request Version 1 Queue Existing providers write here
Request Version 2 Queue New provider write here, New Consumer Reads here
And the ESB picks up the Version 1 Queue messages and transforms them into Version 2 messages and puts them onto the Version 2 queue.
Message transformation is another possible ESB capability.
Have a look at ESB products, see what they can do. As I work for IBM, I'm most familiar with WebSphere ESB
I would say ESB is like a facade into a number of protocals....JMS being one of them.
An addition to the above list is the latest Open Source ESB - UltraESB
JMS is not well suited for the integration of REST services, File systems, S/FTP, Email, Hessian, SOAP etc. which are better handled with an ESB that supports these types natively. For example, if you have a process that dumps a CSV file of 500MB at midnight, and you want another system to pickup the file, parse CSV and import into a database, this can easily be accomplished by an ESB - whereas a solution with just JMS will be bad. Similarly, integration of REST services, with load balancing/failover to multiple backend instances can be done better with an ESB supporting HTTP/S natively.
This Transformation does not happen automatically. You need to configure the mapping or write transformation service
Look at https://access.redhat.com/knowledge/docs/en-US/JBoss_Enterprise_SOA_Platform/4.2/html/SOA_ESB_Message_Transformation_Guide/ch02s03.html
Regards,
Raja Nagendra Kumar,
C.T.O
www.tejasoft.com
ESB offers integration with a lot of different protocols in addition to JMS.
Most use JMS behind the scenes to transfer, stor and move messages. One such solution OpenESB, uses XML format messages.
There are open source ESB which you could checkout -
OpenESB
Apache Camel
MuleESB
WSO2 ESB
JMS implementation like ActiveMQ come with Camel inbuilt into them.
JMS is a protocol for communicating with an underlying messaging layer. ESB operates at a higher level, offering integration with multiple technologies and protocols, one of which would be JMS, in a uniform way that makes management of complex flows much simpler.
There are JMS message brokers , that you can easily configure with ESB. https://docs.wso2.com/display/ESB470/JMS+Transport
JMS and ESB both provide a way of communication between different applications. But the context for JMS and ESB are different. JMS is for simple need. JMS is implemented by JMS Provider. It is Java specific.
Examples of JMS Providers are: Apache Active MQ, IBM MQ, HornetQ etc.
ESB is for complex need. ESB is a component in EAI providing communication facility to various applications. It is generic & not specific to Java. JMS is one of the supported protocols.
Examples of ESB provider are: MuleESB, Apache Camel, OpenESB
Use Case: It may be an overhead to use ESB, if all our communicating applications are in Java and are using the same message format. Here JMS may be sufficient.
We have been discussing this at work and now I am even more confused than ever. As far as I understand it a message bridge is used to talk to a queue in a different domain. Is this correct?
From the Weblogic documentation:
The WebLogic Messaging Bridge is a
forwarding mechanism that provides
interoperability between WebLogic JMS
implementations, and between JMS and
other messaging products. Use the
Messaging Bridge to integrate your
messaging applications between:
Any two implementations of WebLogic JMS, including those from separate
releases of WebLogic Server.
WebLogic JMS implementations that reside in separate WebLogic domains.
WebLogic JMS and a third-party JMS product (for example, MQSeries).
So transferring messages between a queue in one domain and a queue in another is an example of one possible use of a message bridge. The source and destination for your bridge can be queues, topics, or distributed destinations.