RabbitMQ Manual Retry - rabbitmq

How can manual retry work in RabbitMQ after a message has been put onto dead letter queue?
Does RabbitMQ provide an user interface through which you can do this? I assume here that RabbitMQ console does not provide you this capability.

The Rabbit MQ management interface would let you do this crudely, you can go into the deadletter queue, 'get' the message then copy the content. Go to the queue you want to retry the message on and 'publish' it directly to that queue.
Alternatively, you can enable the shovel plugin which allows you to move messages from one queue to another. The RabbitMQ Management plugin directly contains instructions on how to do this.

You can write a consumer / producer using a number of various client libraries. For python a popular library is pika (https://pypi.python.org/pypi/pika).
The script can consume all the messages in a queue, then publish them to another queue.

Related

clear messages from rabbitMQ queue in mule 3

My requirement is to clear all the messages from queue before processing the flow or publishing anything in the queue.
We are using rabbitMQ and due to some reason messages are stucked in the queue and because of that we are facing some issue when we are counting the queue based on the messages. so for the next time before processing we have to clear the queue.
Here we have multiple queue like slave1, slave2,slave3 and when api will be triggered in the process section we have to clear the queue.
Kindly suggest how we can do this in mule3.
Mule 3 has a generic AMQP connector. It does not support administrative commands from a specific implementation like RabbitMQ, so you can't use the connector.
You could use RabbitMQ REST API and call it using the HTTP Request connector. See this previous answer to see how to delete queues with Curl, then implement the same request with HTTP Request: https://stackoverflow.com/a/29148299/721855

Can a MQTT Subscriber be able to take concurrently multiple messages of the Same Topic?

I am trying to create a Subscriber in my Spring Boot Application. My objective is that the publisher will send multiple messages to a topic and I have to get those message and process them .I noticed that the "handleMessage" of both Paho and Apache ActiveMq will process 1 message at a time. Is it possible to make it concurrent??
I have tried the following
Replaced Paho with ActiveMq
Provided concurrency in my listenercontainer
Provided prefetch in my subscribe URL
Please let me know if there is any way to make my MQTT subscriber to take multiple messages concurrently.
Thank You
If you supply your own thread pool you can have the handleMessage method pass the incoming message off to the threadpool to process and then pass the next message off to the pool.

What is good practice to strore application config at RabbitMQ queue?

There is a set of same listeners that listens TCP ports and publishes received data to RabbitMQ queue. I need to have ability to configure listeners from backend at other side of the queue. There is no other connection to listeners except RMQ. What is the good practice to store application config within queue? Must it be a separate queue and exchange? Which parameters queue should have, where to read more? Thanks for any advising.
RabbitMQ doesn't store data. After message is consumed, it will be deleted. If you want to use rmq to send NOTIFICATION to consumers, that is doable. For configuration, my suggestion is zookeeper which also support listener on change.

Message Retry and adding poison message to DLQ in Spring JMS And ActiveMQ

I have a requirement to load messages from two queues and i am using ActiveMQ I have to implement the Retry mechanism in case of any error or network or application server failure and load back into the same Queue. Also, I want to load any poison messages to DLQ.
Please let me know if I can acheive these through Spring JMS. Also, please advise some good examples to accomplish this task. I checked Spring JMS documentation and have not much details in that.
This is a broker function with ActiveMQ - just configure the broker with the appropriate policies.
If using a DefaultMessageListenerContainer, you must use transacted sessions; then, if the listener throws an exception the message will be rolled back onto the queue and the broker's retry/DLQ policies kick in.
See the Spring documentation about enabling transactions.

Is it possible to configure multiple queues to one shovel?

I've got a webservice that accepts messages that can be sent to a RabbitMQ cluster using whatever queue they define. This is so front-end devs can send messages via javascript.
I want to make the webservice more robust so that when we have network trouble, the webservice can still accept messages and then handle them when the network is back up. After some initial reading, it seems that the Shovel plugin should handle this nicely.
What I was thinking was to install a local instance of RabbitMQ on the webservice box with shovel turned on. I can then send all messages through the local RabbitMQ instance and have it push all messages to the cluster and deal with the network problems.
My problem is after looking at the documentation it seems that I have to configure every queue I want to forward to in the shovel config file. If that's the case I'm not sure this will work since we allow clients to define a queue through the webservice on the fly.
I would like to have the webservice take the messages, hand them off to the local rmq instance and have it pass the messages off to the cluster using the same queues/exachanges/etc.
Has anyone tried this or can explain how the shovel plugin works?
Have you considered sending messages to an exchange instead of a queue. Send all messages to one exchange possibly a topic exchange if you need that kind of flexibility. Then have the consumer handle the different messages or different queues from the exchange. Sending to one exchange would make configuring the shovel considerably easier.