I've camel route which is reading from file and pushing the content to active mq queue. In case if the broker disk space is full (may be by some other process which is causing disk space issue), camel route stops pushing content to queue, but no exception is being thrown. I need to raise an alert and send email using on exception block in this case.
You can try to configure the jms/activemq connection factory to use sync sending (turn off async send) so if the broker does not accept the message due disk full etc, then the client (eg Camel) would be able to detect this and raise an exception.
See details at:
http://activemq.apache.org/async-sends.html
http://activemq.apache.org/how-do-i-enable-asynchronous-sending.html
Related
Bit of a Camel newbie but here goes.
I have the following route:
from("activemq:queue:outputQueue").inputType(HelloWorld.class)
.to("log:stream")
.marshal().json(JsonLibrary.Jackson, HelloWorld.class)
.to("http:localhost:5000/messageForYouSir?bridgeEndpoint=true");
This retrieves messages from the queue and sends them to the HTTP endpoint as JSON. Fine.
But what if there is an error? Say a HTTP error code of 400? Then I want the message to stay on the queue. I have tried looking into not acknowledging the message, but have not been able to make it work.
Also I have made an Exception handler
onException(HttpOperationFailedException.class)
.handled(false)
.setBody().constant("Vi fekk ein feil");
But still the messages are gone from the queue. Is there some magic spell that can make Camel not acknowledge the messages when there is some error?
You have to consume transacted from the queue to be able to do a rollback. This is configured on the connection configuration to the broker.
Take a look at the Camel JMS docs (the ActiveMQ component extends the JMS component), especially the sections about cache levels and transacted consumption.
The most simple setup is using broker transactions by simply set transacted = true and lazyCreateTransactionManager = false on the JmsConfiguration. This way no Spring TX manager is required.
If transacted consumption is in place and the HTTP server returns an error (basically if an Exception occurs in the Camel Route), Camel does automatically a rollback (if you don't catch the error).
I am trying to setup a camel context that polls a weblogic jms queue, consumes the message and sends it to a webservice endpoint. Incase any error occurs in the transaction or the target system is unavailable, I need to redeliver the same message without losing sequence/ordering.
I have set up a camel jms route with single consumer and enabled transacted attribute as per https://camel.apache.org/transactional-client.html and set the redelivery as unlimited.
When the transaction fails with messageA, the jms message consumption from weblogic queue is rollbacked and the messageA is marked for redelivery (state string is marked delayed) in weblogic. But during this time if another message reaches the weblogic queue, the camel route picks the messageB and forwards it to the target endpoint although the messageA is still in retrying mode. This distorts the whole ordering of the messages.
The transaction client is used to ensure that messages are not lost while the application is shutdown during redelivery.
I expect that there are no message loss and the messages are always sent in the correct order as per generated into the weblogic queue to the target endpoint.
That a newly arrived message outpaces an existing message that has to be redelivered, sounds like a broker (Weblogic) issue or feature.
I never saw this behavior with ActiveMQ. A failed message that is redelivered, is redelivered immediately by the Apache broker.
It sounds like the message is "put aside" internally to redeliver it later. This can absolutely make sense to avoid blocking message processing.
Is there something like a "redelivery delay" set on Weblogic you can configure? I could imagine that a delayed redelivery is like an internal error queue with a scheduled consumer.
We have a camel route where we read a message from an input queue, process it, set some JMS Header( using Exchange.getIn().setHeader(...) ) and then route the message to some output queue. During MQ Failover scenario, the message is redelivered. However, while the message is redelivered the JMS Headers which I put earlier are lost.
Is there any way to preserve the JMS Headers even after redelivery ?
JMS redelivery
No, not if the message is redelivered from the input queue. Simply because it is the same original message you received before. The JMS broker does not know anything about the modifications you did in the Camel route.
However, this is normally not a problem. Because on a redelivery, the same consumer consumes the message again and does the same modifications again on the message.
As soon as you reach a "transaction boundary" in your route (that means, something has done that cannot be repeated or would yield a different result), you should put the modified message on another queue to "save" its current state.
From there you can continue with another consumer and so forth. If you build a processing chain like this, your system is a Pipes and Filter EIP.
Camel redelivery
Another possibility is to use the Camel ErrorHandler. It handles errors on a single route-step level. It can also do retries, but then you have to make sure the message is correctly handled if all Camel retries fail (for example send the message to an error queue).
As long as the broker redelivery is the last resort for your message, you should build your system with potential redelivery in mind.
I have this problem, too. i'm forced to convert my objects to json and save in headers of jms. and after i convert again to object. it's worked for me!
I have:
Camel route (transacted=true), consuming from an MQ Queue
Using Spring's WebSphereUowTransactionManager
Transactionality works
Running on IBM Liberty
But, I get this message:
Setup of JMS message listener invoker failed for destination 'MY.QUEUE' - trying to recover.
Cause: Local JMS transaction failed to commit; nested exception is com.ibm.msg.client.jms.DetailedIllegalStateException:
MQJCA1020: The session is closed.
The application attempted to use a JMS session after it had closed the session.
Modify the application so that it closes the JMS session only after it has finished using the session.
This appears to be related to this other Stack Overflow question, but I've tried changing the configuration in server.xml, with no success.
You can try setting cacheLevelName=CACHE_CONSUMER which allows to re-use the JMS consumer and avoids endless of creation/destruction of JMS resources, as indicated by the error message may be the cause.
You can see more about the importanse of cache levels on the Camel JMS documentation: http://camel.apache.org/jms
I have a small Camel route which just forward messages to another queue with an expiration time like this:
#Override
public void configure() throws Exception {
defaultOnException();
// Route all messages generated by system A (in OUTBOUND_A) to system B (INBOUND_B)
// #formatter:off
from("activemq:queue:OUTBOUND_A")
// ASpecificProcessor transform the coming message to another one.
.processor(new ASpecificProcessor())
.to("activemq:INBOUND_B?explicitQosEnabled=true&timeToLive={{b.inbound.message.ttl}}");
// #formatter:on
}
I need the messages posted in INBOUND_B to be persistent and by default the expired message goes to ActiveMQ.DLQ queue after expired.
I know I can modify the ActiveMQ configuration in the conf/activemq.xml with
<policyEntry queue="INBOUND_B">
<!--
Tell the dead letter strategy not to process expired messages
so that they will just be discarded instead of being sent to
the DLQ
-->
<deadLetterStrategy>
<sharedDeadLetterStrategy processExpired="false" />
</deadLetterStrategy>
</policyEntry>
But I would prefer not to change the ActiveMQ configuration (because it needs a restart) and I am wondering if it is possible to send such policy through the Camel endpoint configuration?
No, ActiveMQ broker side configuration cannot be updated via the client, that would lead to all sorts of security problems. You would need to update the broker configuration and possibly not need a restart if you use the runtime configuration plugin on the broker.