Application Data Flow:
JSon Messages--> Active MQ --> Spring XD-- Business Login(Transform JSon to Java Object)--> Save Data to Target DB--> DB.
Question:
Sprin-Xd is running in cluster mode, configured with Radis.
Spring XD picks up the message from the Active message queue(AMQ). So message is no longer in AMQ. Now while one of the containers where this message is being processed with some business logic suddenly goes down. In this scenarios-
Will Spring-XD framework automatically re-process that particular message ? what's mechanism behind that?
Thanks,
Abhi
Not with a Redis transport; Redis has no infrastructure to support such a requirement ("transactional" reads). You would need to use a rabbit or kafka transport.
EDIT:
See Application Configuration (scroll down to RabbitMQ) and Message Bus Configuration.
Specifically, the default ackMode is AUTO which means messages are acknowledged on success.
Related
I have used the sample configuration as was listed in the spring io docs and it is working fine.
<int-kafka:message-driven-channel-adapter
id="kafkaListener"
listener-container="container1"
auto-startup="false"
phase="100"
send-timeout="5000"
channel="nullChannel"
message-converter="messageConverter"
error-channel="errorChannel" />
However, when i was testing it with downstream application where i consume from kafka and publish it to downstream. If downstream is down, the messages were still getting consumed and was not replayed.
Or lets say after consuming from kafka topic , in case i find some exception in service activator, i want to throw some exception as well which should rollback the transaction so that kafka messages can be replayed.
In brief, if the consuming application is having some issue , then i want to roll back the transaction so that messages are not automatically acknowledged and are replayed back again and again unless it is succesfuly processed.
That's not how Apache Kafka works. There is the TX semantics similar to JMS. The offset in Kafka topic has nothing with rallback or redelivery.
I suggest you to study Apache Kafka closer from their official resource.
Spring Kafka brings nothing over the regular Apache Kafka protocol, however you can consider to use retry capabilities in the Spring Kafka to redeliver the same record locally : http://docs.spring.io/spring-kafka/docs/1.2.2.RELEASE/reference/html/_reference.html#_retrying_deliveries
And yes, the ack mode must be MANUAL, do not commit offset into the Kafka automatically after consuming.
I am currently trying to write an adapter which will consume messages from ActiveMQ and publish it to Kafka.
I am thinking of using spring integration to integrate these two messaging systems.
My problem is that my application will not maintain registry of the Models using which many applications will publish the records to activeMQ. I want to receive these javax jms message and want to perform some transformation like adding jmscorrelationId into kafka message.
ALso, another requirement is to send acknowledgement to active mq only when kafka send/publish is successfull.
Can ack be send back to activemq using spring integration?
Will spring integration be a good option?
Kindly note my tech architect is not in favor of using Camel/Mule. Also, he does not want to use Kafka Connect as i was planning to use Kafka connect source.
Please suggest.
The Spring Integration Kafka extension project has a sync mode for publishing, which will block the thread until Kafka confirms delivery (or throw an exception on a failure).
The JMS inbound gateway can be used to return a reply to a JMS queue.
You can add transformers (or whatever) in the flow to modify the message.
So using JMS and ActiveMQ, I can be sure that my message sent from my Spring Boot application using JmsTemplate will reach it's destination application even if that destination application is down at the time I send the message to ActiveMQ. As when the destination application starts up, it grabs the message from the queue. Great!
However.
What happens if my Spring Boot application tries to send a JMS message to a queue on the ActiveMQ server, but the ActiveMQ server is down at that point or the network is down and I get a connection refused exception?
What is the recommended way to make sure my application keeps trying to re-sends the message to ActiveMQ until it is successful? Is this something I have to develop into my application myself? Are there any nifty Spring tools or annotations which do this for me? Any advice on best practice or how I should be handling this scenario?
You can try Spring-Retry. Has lots of fine grain controls for it:
http://www.baeldung.com/spring-retry
https://github.com/spring-projects/spring-retry
If it is critical that you don't lose this message, you will want to save it to some alternative persistent store (e.g. filesystem, local mq server) along with whatever retry code you come up with. But for those occasional network glitches or a very temporary mq shutdown/restart, Spring-Retry alone should do the trick.
Couple of approaches I can think of
1. You can set up another ActiveMq as fallback. In your code you don't have to do anything, just change your broker url from
activemq.broker.url=tcp://amq01.blah.blah.com:61616
to
activemq.broker.url=failover:(tcp://amq01.blah.blah.com:61616,tcp://amq02.blah.blah.com:61616)?randomize=false
The rest is automatically taken care of. i.e. when one of them is down, the messages are sent to other.
Another approach is to send to a internal queue (like seda, direct) when activemq is down and read from there.
Adding failover to the url is one appropriate way.
And another reasonable way is to making sure activemq always online , as activemq has the master-slave mode(http://activemq.apache.org/masterslave.html) to get high availability.
Our project is to integrate two applications, using the REST API of each and using JMS (to provide asynchronous nature). Application-1 writes the message on the queue. The next step is to read the message from the queue, process it, and send it to application2.
I have two questions:
Should we use one more queue for storing messages after processing and before sending them to application2?
Should we use spring batch or spring integration to read/process the data?
Or you don't show the whole premise, or you really try to overhead your app. If there is just need to read messages from the queue, there is just enough to use Spring JMS directly... From other side with the Spring Integration and its Adapters power you can just process messes from the <int-jms:message-driven-channel-adapter> to the <int-http:outbound-channel-adapter>.
Don't see reason to store message somewhere else in the reading and sending process. Just because with some exception here you just rollback your message to the JMS queue back.
I am using Spring Integration in my project.
We have a requirement that in case where we will have stop Spring standalone service if database goes down.
In Message listener when I persist the data into database I check if I get CannotGetJdbcConnectionException then stop the Spring service using applicationContext.close() method.
Problem here is if I received any message on to the Queue and database goes down.
I tried to close Spring service then all resource goes down except DefaultMessageListenerContainer that holds that message.
If I terminate the process manually then message goes into inbound Queue which is correct.
Is there any way I could stop Spring service forcefully and put the message back to Inbound Queue?
I hope I am clear with my point here.
Thanks
Sachin
You should configure the DMLC with setSessionTransacted(true) (acknowledge="transacted" when using the namespace to define the endpoints).
Then any in-flight messages will be rolled-back onto the queue.