Im doing this :
channel.basicPublish("myexchange", "routing", MessageProperties.PERSISTENT_TEXT_PLAIN,
"message".getBytes());
I would like to retry later to send the message if the publish didn't succeeded (connection loss, ...) but basicPublish is a void function and there is no callback in the arguments
Any idea ?
You are looking an HA client,
By default you have to implement the feature by your self.
If you use java there is :
https://github.com/joshdevins/rabbitmq-ha-client (it's just a bit old but it think it still work).
Anyway, if you want implement the functionality you have catch the exception and re-try later.
If the client lose the connection you should re-connect the client before re-send the message.
On the version 3.3.0 the last features is implemented by default to the java client:
java client
enhancements
14587 support automatically reconnecting to server(s) if connection is
interrupted
This point is very important you want send the messages sequentially.
A simple solution is put the messages in a client list and then remove the message from the list only if the message has been sent correctly.
I think you could find interesting also the Publisher Acknowledgements
Related
I have written an application, that successfully listens to a multicast-host 239.255.255.250:1900 and [FF02::C]:1900. I receive the desired NOTIFY and M-SEARCH messages using spring-integration-ip's MulticastSendingMessageHandler.
However: while I am able to send messages using the UnicastSendingMessageHandler, it does not seem like e.g. VLC will recognize my running server.
I went through the UPnP Device Architecture PDF back and forth and manually sent the 3+2+1 NOTIFY messages and also responded to M-SEARCH, but somehow I am not able to make e.g. VLC recognize my server.
I also see no access on my HTTP server (separate application on a different port, but properly linked in the LOCATION attribute of the NOTIFY and M-SEARCH-response messages). No attempts at all.
Do I need to send the data using MessageHeaders (headers) instead of payload? What's the pre-requisite for a possible media server to be listed? Sending the NOTIFY messages? Responding to M-SEARCH messages? More?
And what are the allowed devicetype and servicetype values? Or do they vary?
If anyone wants, I can add some code, but the listening part is working alright and messages are sent, just supposedly not understood by their receivers (sending using Unicast to the address, who sent the M-SEARCH message, but on port 1900).
Honestly: I am not sure how to even word my question(s). I tried reading through the RSSDP source code, but I still do not fully get it.
Any pointers are greatly welcomed.
I have a WCF application which consists in some async communications with ecternal services. When we start a new expedient, a new instance is created; it process data and send an xml to a external service and waits for the response. This response requires that a person review the xml and send the response so it usually it is delayed for a long time. For this reason, the workflow go to idle and we use persistence with AppFabric.
The fact is that sometime, when we receive the response, the next exception is raised:
The execution of the InstancePersistenceCommand named {urn:schemas-microsoft-com:System.Activities.Persistence/command}LoadWorkflowByInstanceKey was interrupted by an error.
Normally this error does not occur, it can occur very sporadically. However, we are trying to update the app to include a new functionality (it does not modify the workflow) but when the application is deployed to the server, the instances that were created with the old deployment and were waiting for the response, throw this exception when they receive the response from the external service. However, the instances initiated with the new deployment process the response without problem.
I have been looking for information about this problem but I haven't found much. Anybody can help me?
SOLUTION:
Thanks a lot for your answer, it may be helpful for me in the future. In this case, the problem was that I was updating an assembly version of one of the implicated project (to upload a nuget package) and for a reason that I don’t understand, the instances created with an old version raised this exception when the service with the new version had to manipulate the mentioned instances.
If I change the assembly version to upload the nuget and then set the original version and deploy with this version, everything works ok. Anybody knows what is the reason?
Thanks a lot.
This may be because there is a program running in the background and trying to extend the lock on the instance store every 30 seconds, and it seems that whenever the connection to the SQL service fails, it marks the instance store as invalid.
You can try <workflowIdle timeToUnload="0"/>, if it doesn't work you can look at the methods provided by other links.
Windows workflow 4.0 InstancePersistenceCommand Error
Why do I get exception "The execution of the InstancePersistenceCommand named LoadWorkflowByInstanceKey was interrupted by an error"
WF4 InstancePersistenceCommand interrupted
I use ApiKit to receive queries. Occasionally I get the following line in a log file:
WARN org.mule.module.http.internal.listener.grizzly.ResponseCompletionHandler - HTTP response sending task failed with error: Locally closed
It seems that in this case the integration has not sent a response to the party that called the integration. I thought that there might be a sort of timeout before ApiKit closes the connection to caller but based on timestamps that might not be the case as everything happens within a second.
In this case the payload is sent to Artemis queue before this warning and despite the warning the message is read from Artemis normally and the whole flow works otherwise just fine besides this warning and not sending the response.
So, am I correct when I think that this warning is an indication why the response is not sent? In addition to that what can be done to prevent this situation?
In our system, virtual hosts configuration is stored in redis. During connection setup, when the SNI is received, we would like to query redis for the correct certificate and key pair to use for the TLS connection and create a new Context instance with that attached.
The bulk of the code is similar to the accepted answer here: Twisted listenSSL virtualhosts
The issue we are facing is that, since accessing the certificates involves an additional network operation, we would like to make the set_tlsext_servername_callback function return a deferred.
Is there a way to tell Twisted/pyOpenSSL to wait until the deferred fires?
Edit: I found this link which seems promising, but falls short of providing a solution: https://mta.openssl.org/pipermail/openssl-dev/2015-January/000480.html
You can find an example of Twisted and SNI here: https://pypi.python.org/pypi/txsni. I would really, really like that callback to be able to take a Deferred. I think that the way to do this would be to pause the underlying transport from delivering any further bytes either in or out (stopReading/stopWriting) and then resume when the Deferred fires, after doing the rest of the SNI dance. However, I'm not even sure if this is possible with OpenSSL, because the SNI is received with the rest of ClientHello and you may need to be able to react immediately to serve the correct certificate. In this worst-possible-case scenario, you could feed the first chunk of bytes you receive into a dummy memory-BIO, wait for the TLS handshake, throw it away and never deliver any generated responses, and then don't initialize your "real" sub-transport until you've decided on which context object to use.
Hope this helps - and if you figure it out, please contribute a patch to TxSNI or Twisted!
I have wrote server-client application.
Server Side
server will initilise a queue queue1 with routing key key1 on direct exchange.
After initilise and declaration it consume data whenever someone write on it.
Client Side
client will publish some data on that exchange using routing key key1 .
Also i have set mandotory flag to true before i publish.
Problem
everything is fine when i start server first .but i got problem when i start client first and it publish data with routing key. When client published data there is no exception from broker.
Requirement
I want exception or error when i published data on non existing queue.
If you will publish messages with mandatory flag set to true, then that message will returned back in case it cannot be routed to any queue.
As to nonexistent exchanges, it is forbidden to publish messages to non-existent exchanges, so you'll have to get an error about that, something like NOT_FOUND - no exchange 'nonexistent_exchange' in vhost '/'.
You can declare exchanges an queues and bind them as you need on client side too. These operations are idempotent.
Note, that creating and binding exchanges and queues on every publish may have negative performance impact, so do that on client start, not every publish.
P.S.: if you use rabbitmq-c, then it is worth to cite basic_publish documentation
Note that at the AMQ protocol level basic.publish is an async method:
this means error conditions that occur on the broker (such as publishing to a non-existent exchange) will not be reflected in the return value of this function.
I spend a lot time to find do that. I have a example code in python using pika lib to show how to send messsage with delivery mode to prevent waiting response when send message to noneexist queue(broker will ignore meessage so that do not need receive response message)
import pika
# Open a connection to RabbitMQ on localhost using all default parameters
connection = pika.BlockingConnection()
# Open the channel
channel = connection.channel()
# Declare the queue
channel.queue_declare(queue="test", durable=True, exclusive=False, auto_delete=False)
# Enabled delivery confirmations
channel.confirm_delivery()
# Send a message
if channel.basic_publish(exchange='test',
routing_key='test',
body='Hello World!',
properties=pika.BasicProperties(content_type='text/plain',
delivery_mode=1),
mandatory=True):
print('Message was published')
else:
print('Message was returned')
Reference:
http://pika.readthedocs.org/en/latest/examples/blocking_publish_mandatory.html