I am working on Bpel 12c. I have a producer BPEL process which loops for 10 times and publishes a message to a JMS queue for each iteration. I also have a BPEL process which consumes from the above JMS queue. Everything works perfectly. But my only concern is, If I got to EM Console and try to open the instance of the consumer, I am not seeing 10 separate instances instead I am seeing the instance of the producer and when I open this instance, it shows all the 10 consumers under it. This behaviour is Okay if the parent process invokes a child process. But here It is completely two separate process and why It groups like this? Imagine if there are 100 such messages, the flow will not open at all and cause memory issue. Please let me know if there is a way to modify this behaviour and Will i be able to see all 10 instances separately?
It looks like expected behaviour from Oracle SOA, if it know of an initiating composite then it shows the whole trail (Ie the produce and the consumption), it doesnt matter if you build the consumer in a seperate project/or a the same one it still links them.
Related
We have a requirement in where we need to send only one message at a time to a backend process. The call back of this process takes around an hour, only after the call back can we send another request to the process.
I am trying to achieve this by using a manager bpel process that will hold the messages first if there is already something being processed in the backend, and then send it once it realizes that the backend is free. This approach will work, but our architect wants a cleaner solution. He suggested using JMS queues. The idea is for the jms queue to messages to be read by a amanger one at a time, only moving on to the next one once we receive the callback from the backend and we know that the composite and bpel instance is finished. I've been scouring the internet for weeks, but I couldn't find a working jms based solution for my requirement.
I've tried the suggestions for this link but turning on unit of order and acknowledgement properties does nothing.
Try this approach!!
Use a event driven bpel process.
Use a database flag as your next trigger. (flag is TRUE)
jms Adapter receives first message from the queue. Here use a delay in the adapter since you are expecting the bpel to be long running. use below setting.
<binding.jca config="MyServiceInboundQueue_jms.jca">
<property name="minimumDelayBetweenMessages">10000</property>
<property name="singleton">true</property>
</binding.jca>
if flag == TRUE in the db causes the db adapter to proceed with the bpel process,
else skip the bpel.
mark flag==FALSE
call the backend system
callback is received after an hour.
set flag==TRUE
Hi Jonar,
At my company we always use JMS queues for Asynchronous messaging. You could do with a delay timer build in your composite set to 1 hour and 15 minutes for example, and it will work most of the time, but its hella messy. The whole idea is for any asynchronous process to kick off when a message is put upon its queue target (specified by the JMS queue). The JMS adapter in the composite of your project will pick up the message from the queue when it is free to process the queue. The goal for you would be to put the message on the queue and pick it up from it using the adapter. It will know which message to pick up because you specify which queues it listens to in the adapter.
The following blog post by John-Brown Evans eplains the whole process from step one. It might be a bit tedious, but I found it very helpful. Its using SOa Suite 11g instead of the nowadays more commonly used 12c, but its fundamentals remain the same.
Awesome JMS queue tutorial
I hope this works for you!
Cheers,
Jesper
Good day everyone.
1) I have a simple app which creates JMSProducer, ActiveMQ Query and send some messages to query.
2) I also have the application which is a subscriber
of ActiveMQ Query (it receives messages from application above).
This is the situation:
I create another server config to my subscriber-App, and launch it twice at a time on different ports.
(for example: subscriber-App1 started at jetty-http-port-9998/jetty-ssl-port-9994; subscriber-App2 started at jetty-http-port-9999/jetty-ssl-port-9995).
I open subscriber-App1 console and subscriber-App2 console at Intellij IDEa and begin to send messages by producer-App. And I see that subscribers takes messages by rotation: when I send it the first time - subscriber1 takes it; 2nd time - subscriber2; 3rd time - subscriber1 etc.
The question is: how can I configure subscriber-Application to give it exclusive access to data? The main condition is: if there is the one Subscriber of my Queue - another applications can't receive messages from Queue. And if I launch two subscriberApps on different ports - all messages will be received by only one of them.
Thank you in advance!
I believe you should be able to use the exclusive consumer feature to achieve your goal.
I am working on an existing Spring jms application that pulls messages from ActiveMQ using jms:inbound-gateway. This application is a job processor that takes jobs off a queue and sends results back to the queue. Everything currently works great.
I would like to modify this application to accept one and only one job, process it, and then exit, but I have not been able to find a way to cleanly do this. The method that is called must return the results, and the results are automatically placed back onto the queue by Spring. Is there any way to tell Spring to stop accepting messages at 1? How would you know when it's done sending the reply message so you can exit.
In a more general case, if you had an application that wanted to stop accepting messages and finish processing them all so you could exit cleanly, how can that be done?
Thanks in advance for any advice.
It sounds like you should be using JmsTemplate.receive . Inbound gateway is meant for a message driven model. It sounds like while you are using a message queue for transport, you're not really doing a message driven model of processing. Obviously that's not a problem but if your aim is to process a single message you should just use JmsTemplate.
Another way to do this is to use the default message listener container, ensure threads is set to one and then make sure your activemq setup has no read-ahead setup (i.e. reads one message at a time and no more). Then, at the end of your onMessage method, call the DMLC.stop method.
I have the problem that I have to run very long running processes on my Webservice and now I'm looking for a good way to handle the result. The scenario : A user executes such a long running process via UI. Now he gets the message that his request was accepted and that he should return some time later. So there's no need to display him the status of his request or something like this. I'm just looking for a way to handle the result of the long running process properly. Since the processes are external programms, my application server is not aware of them. Therefore I have to wait for these programms to terminate. Of course I don't want to use EJBs for this because then they would block for the time no result is available. Instead I thought of using JMS or Spring Batch. Does anyone ever had the same problem or an advice which solution would be better?
It really depends on what forms of communication your external programs have available. JMS is a very good approach and immediately available in your app server but might not be the best option if your external program is a long running DB query which dumps the result in a text file...
The main advantage of Spring Batch over "just" using JMS as an aynchronous communcations channel is the transactional properties, allowing the infrastructure to retry failed jobs, group jobs together and such. Without knowing more about your specific setup, it is hard to give detailed advise.
Cheers,
I had a similar design requirement, users were sending XML files and I had to generate documents from them. Using JMS in this case is advantageous since you can always add new instances of these processes which can consume and execute the jobs in parallel.
You can use a timer task to check status or monitor these processes. Also, you can publish a message to a JMS queue once the processes are completed.
What is the best approach to connect to websphere mq v7.1 and clear all the messages of one or more specified queues using Java and JMS? Do I need to use Websphere MQ specific java API? Thanks.
Like all good questions, "it depends."
The queue can be cleared with a command only if there are no open handles on the queue. In that case sending a PCF command to clear the queue is quite effective, but if there are open handles you get back an error. PCF commands are of course a Java feature and not JMS because they are proprietary to WebSphere MQ.
On the other hand, any program authorized to perform destructive gets off a queue can clear the queue. In this case, just loop over a get until you get the 2033 return code indicating the queue is empty. This can be performed using JMS or Java but both of these manage the input buffer for you. If the queue is REALLY deep then you end up moving all that data and if the app is client connected, you are moving it at network speed instead of in memory.
To get around this, you need to specify a minimal amount of buffer and as one of the GET options also specify MQGMO.TRUNCATED_MSG_ACCEPTED. This moves only the message header during the get calls and can be significantly faster.
Finally, if you are doing this programamtically and regardless of which method you use, spin off several threads and don't use syncpoint. You actually have to go out of your way to get exclusive input on a queue so once you get a session, just spawn many threads off of it. Close each thread gracefully and shut down the the session once all the threads are closed.